WO2016042385A1 - Control device and program - Google Patents

Control device and program Download PDF

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Publication number
WO2016042385A1
WO2016042385A1 PCT/IB2015/001645 IB2015001645W WO2016042385A1 WO 2016042385 A1 WO2016042385 A1 WO 2016042385A1 IB 2015001645 W IB2015001645 W IB 2015001645W WO 2016042385 A1 WO2016042385 A1 WO 2016042385A1
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WO
WIPO (PCT)
Prior art keywords
communication
multicast
request information
control device
relay device
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PCT/IB2015/001645
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French (fr)
Japanese (ja)
Inventor
敬司 阪口
Original Assignee
パナソニックIpマネジメント株式会社
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Publication of WO2016042385A1 publication Critical patent/WO2016042385A1/en

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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W4/00Services specially adapted for wireless communication networks; Facilities therefor
    • H04W4/06Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services

Definitions

  • the present invention generally relates to a control device and a program, and more specifically to a control device and a program that perform communication by multicast.
  • Multicast is a technique for allowing data to reach a plurality of devices in a single transmission.
  • information for requesting transfer of a multi-destination message is transmitted to a router interposed between devices.
  • a representative device of a group (multi-destination group) composed of a plurality of devices sends a presence signal corresponding to information for requesting transfer of a multi-destination message to a group control unit corresponding to a relay device (router). Send regularly to.
  • the multi-destination message is received by the group control unit, the multi-destination message is transferred to all devices belonging to the group.
  • the control device provides a communication path for receiving the request information after receiving the request information for requesting transfer of data transmitted by multicast until the end of the multicast transfer period.
  • a control device that communicates with one or more communication devices to be controlled via a relay device that permits transfer of the data, and controls the one or more communication devices, the relay device And a communication processing unit that communicates with the one or more communication devices via the relay device, and the communication processing unit includes the request information within the multicast transfer period. Transmitting to the communication unit.
  • the program of the present invention is a program for causing a computer to function as the control device. Advantages of the Invention The present invention has an effect that multicast communication can be performed while preventing a decrease in reliability of the entire system.
  • FIG. 3 is a flowchart illustrating the operation of the control device according to the first embodiment. It is a figure explaining the structure of the control system of Embodiment 2, and a control apparatus. It is a sequence diagram explaining the operation
  • 6 is a flowchart for explaining the operation of the control device according to the second embodiment. It is a figure explaining the structure of the control system of Embodiment 3, and a control apparatus. It is a figure explaining the structure of the control system of Embodiment 4, and a control apparatus.
  • FIG. 3 is a flowchart illustrating the operation of the control device according to the first embodiment. It is a figure explaining the structure of the control system of Embodiment 2, and a control apparatus. It is a sequence diagram explaining the operation
  • 6 is a flowchart for explaining the operation of the control device according to the second embodiment. It is a figure explaining the structure of the control system of Embodi
  • FIG. 10 is a sequence diagram illustrating an operation outline of a control system according to a fourth embodiment. 10 is a flowchart for explaining the operation of the control device according to the fourth embodiment.
  • FIG. 10 is a sequence diagram for explaining an operation outline of a control system according to a fifth embodiment. 10 is a flowchart for explaining the operation of the control device of the fifth embodiment.
  • FIG. 10 is a sequence diagram illustrating an outline of operation of a control system according to a sixth embodiment. 14 is a flowchart for explaining the operation of the control device of the sixth embodiment.
  • FIG. 10 is a sequence diagram for explaining an operation outline of a control system according to an eighth embodiment. 16 is a flowchart for explaining the operation of the control device of the eighth embodiment.
  • the control system 10 of the present embodiment includes a control device 20, a relay device 30, and communication devices 41 and 42.
  • the control device 20 and the relay device, the relay device 30, and the communication devices 41 and 42 are connected by an Ethernet (registered trademark) standard cable or IEEE 802.11 standard wireless communication media 11 to 13. , Each connected.
  • the control device 20 is a device that communicates with the relay device 30 and communicates with the communication devices 41 and 42 via the relay device 30 by multicast.
  • multicast data data transmitted by multicast is referred to as multicast data.
  • the relay device 30 is a router that supports, for example, IGMP Snooping.
  • IGMP Internet Management Protocol
  • IETF Internet Engineering Task Force
  • IGMP determines whether or not multicast data transmitted from a different network is transferred to a network managed by the IGMP.
  • IGMP Snooping is a function that applies IGMP, and is a layer 2 function in the OSI reference model that eavesdrops on request information (IGMP Report) transmitted by the control device 20 and determines whether multicast data can be transferred for each communication port. It is.
  • the request information is information that the control device 20 requests the relay device 30 to transfer data of a specific multicast address group (multicast data), and includes the multicast address that the control device 20 wants to receive. .
  • the relay device 30 having IGMP Snooping determines whether or not transfer by multicast is permitted for each communication port.
  • the relay device 30 equipped with this function receives the request information, the relay device 30 permits the communication port that has received the request information to transfer by multicast until the predetermined period ends after receiving the request information. Thereby, the relay apparatus 30 can manage the multicast transfer period for each communication port.
  • the relay device 30 eavesdrops on the request information transmitted by the control device 20 by using IGMP Snooping, and identifies and manages the multicast address for which the control device 20 requests transfer from the request information.
  • the control device 20 receives the data (multicast data) of the multicast address group that the control device 20 requests to transfer, the relay device 30 transfers the multicast data to the communication port 33 connected to the control device 20, and the other communication ports transfer the data. Control not to.
  • the relay device 30 manages a period during which multicast data transfer is permitted (multicast transfer period) for each communication port that requests multicast data transfer.
  • the relay device 30 receives the multicast data addressed to the multicast address group that matches the request information from the communication device 41 after the request information of the control device 20 is received and the time length of the multicast transfer period is exceeded. In this case, the relay device 30 does not transfer the data to the communication port connected to the control device 20.
  • the time length of the multicast transfer period is, for example, 5 minutes.
  • the communication devices 41 and 42 are devices that handle multicast data, such as an air conditioner, a lighting fixture, a personal computer, a tablet terminal, and the like, and have a processor and a memory. The functions of the communication devices 41 and 42 are realized by the processor executing a program stored in the memory.
  • configurations of the control device 20 and the relay device 30 will be described.
  • Control device 20 As shown in FIG. 1, the control device 20 includes a first communication unit 21 (communication unit) and a communication processing unit 22.
  • the control device 20 includes a processor and a memory, and the function of the communication processing unit 22 is realized by the processor executing a program stored in the memory.
  • the processor which the control apparatus 20 has is a processor whose performance is higher than the processor which the communication apparatuses 41 and 42 have.
  • the first communication unit 21 communicates with the relay device 30 via the communication medium 11.
  • the first communication unit 21 communicates with the communication devices 41 and 42 via the communication medium 11 and the relay device 30.
  • the first communication unit 21 periodically transmits request information under the control of the communication processing unit 22 described later.
  • the first communication unit 21 transmits request information (Set request) for requesting the state setting change to the communication devices 41 and 42 via the relay device 30.
  • the first communication unit 21 receives response information (Set response) indicating that the request information has been received from the communication devices 41 and 42.
  • the first communication unit 21 receives multicast data representing the state after the setting change from the communication devices 41 and 42.
  • the communication processing unit 22 controls the overall operation of the control device 20.
  • the communication processing unit 22 causes the first communication unit 21 to periodically transmit the request information.
  • the communication processing unit 22 causes the first communication unit 21 to transmit request information and receive response information and multicast data.
  • (2) Relay device 30 As shown in FIG. 1, the relay device 30 includes a second communication unit 31 (communication path) and a control unit 32.
  • the relay device 30 includes a processor and a memory, and the function of the control unit 32 is realized by the processor executing a program stored in the memory.
  • the second communication unit 31 includes a plurality of communication ports (communication paths). In the present embodiment, the relay device 30 includes three communication ports 33 to 35.
  • the communication port 33 is connected to the first communication unit 21 of the control device 20 via the communication medium 11.
  • the communication port 34 is connected to the communication device 41 via the communication medium 12, and the communication port 35 is connected to the communication device 42 via the communication medium 13.
  • the communication ports 33 to 35 Upon receiving data (for example, request information and multicast data) transmitted from the connection destination device, the communication ports 33 to 35 output the received data to the control unit 32.
  • the control unit 32 controls the overall operation of the relay device 30.
  • the control unit 32 has a first management table that determines whether multicast data can be transferred for each communication port managed by the relay device 30.
  • a communication port, a multicast group address to be transferred, an expiration date, and the like are associated with each other from request information from the control device 20, the communication device 41, and the communication device.
  • the expiration date is the time when the multicast transfer period ends.
  • the control unit 32 deletes the request information from the first management table.
  • the control unit 32 checks whether a multicast group address that matches the multicast group address of the received multicast data exists in the first management table. When determining that it exists in the first management table, the control unit 32 transfers the received multicast data to the communication port corresponding to the multicast group address of the multicast data.
  • the control unit 32 transfers the request information to the communication port to which the communication device that is the destination of the received request information is connected.
  • Communication devices 41 and 42 Since the communication devices 41 and 42 have the same function, the communication device 41 will be described here.
  • the communication device 41 receives request information from the control device 20 via the relay device 30, the communication device 41 transmits response information to the control device 20 via the relay device 30.
  • the communication apparatus 41 changes the setting of a state based on the content of the received request information. For example, when the communication device 41 is an air conditioner, if the content of the request information is a request “decrease the set temperature once”, the communication device lowers the set temperature once.
  • the communication device 41 transmits multicast data indicating the state after the setting change.
  • the setting of the state is changed by an operation of the attached remote controller or the like, the communication device 41 transmits multicast data indicating the state after the setting change.
  • the control apparatus 20 transmits request information at the time of starting (step S5). After transmitting the request information in step S5, the control device 20 transmits the request information periodically (for example, every 3 minutes) (steps S10 to S20). Here, the transmission period of the request information is 3 minutes, but the transmission period may be equal to or less than the time length of the multicast transfer period.
  • the relay device 30 transmits the multicast data to the control device 20 that requests the multicast data (steps S25 and S30).
  • the control device 20 transmits the request information periodically (for example, every 3 minutes) even after receiving the multicast data (step S35). Accordingly, the control device 20 can receive the multicast data transmitted from the communication devices 41 and 42 via the relay device 30 by transmitting the request information within the multicast transfer period of the relay device 30.
  • the communication processing unit 22 of the control device 20 causes the first communication unit 21 to transmit request information at the time of activation (step S100).
  • the communication processing unit 22 determines whether a predetermined time (for example, 3 minutes) has elapsed (step S105).
  • the communication processing unit 22 transmits the request information to the first communication unit 21 (step S110). After the request information is transmitted, the process returns to step S105. If it is determined that the predetermined time has not elapsed (“No” in step S105), the process waits for the elapse of the predetermined time.
  • the control device 20 transmits request information every 3 minutes. The time length of the multicast transfer period managed by the relay device 30 is 5 minutes. For this reason, the control device 20 always transmits the request information within the multicast transfer period.
  • the control device 20 can receive multicast data even if the relay device is a relay device that manages the transfer period of multicast data. Further, normally, control of other devices (communication devices 41 and 42) is performed by a device (control device 20) having higher processing performance than the other devices. Therefore, even if the control device 20 periodically transmits the request information, the processing load is low as compared with the case where the other device performs. That is, the reliability and reliability of multicast data transmission / reception is improved as a whole system.
  • the relay device 30 is a relay device compatible with IGMP Snooping.
  • the relay device 30 is a relay device compatible with IGMP and manages a different IP network from the own device. And the connection point is different.
  • the present embodiment will be described focusing on differences from the first embodiment.
  • symbol is attached
  • the control system 10 of this embodiment shown in FIG. 4 includes a control device 20, relay devices 30 and 50, and communication devices 41 and 42.
  • the relay device 30 and the relay device 50 are routers that manage different IP networks, and are routers that support IGMP.
  • the communication ports 33, 34, and 35 are communication ports for communicating with the IP network managed by the relay device 30.
  • the communication port 36 (communication path) is a communication port for communicating with different IP networks.
  • the relay device 50 is connected to the communication port 36 by the communication medium 14.
  • the first communication unit 21 When receiving the inquiry information from the relay device 30, the first communication unit 21 outputs the received inquiry information to the communication processing unit 22, and transmits the request information to the relay device 30 under the control of the communication processing unit 22.
  • the inquiry information is information for inquiring whether or not to receive multicast data, and is, for example, IGMP Query.
  • the communication processing unit 22 When the communication processing unit 22 receives the inquiry information from the relay device 30 via the first communication unit 21, the communication processing unit 22 transmits the request information to the first communication unit 21 as a response, and stops the subsequent periodic transmission of the request information. Thus, the first communication unit 21 is controlled.
  • the relay device 30 is, for example, a router that supports IGMP.
  • the relay device 30 periodically transmits inquiry information (IGMPQuery), which is a query for confirming whether there is a device that desires to receive multicast data in the IP network managed by the relay device 30 (for example, 5 minutes).
  • IGMPQuery inquiry information
  • a device that desires to receive multicast data addressed to a specific group notifies the relay device 30 of the multicast address that it desires to receive.
  • the relay device 30 when the relay device 30 receives the data transmitted by multicast, the relay device 30 transmits the received multicast data to the network that requests transfer of the multicast data.
  • the relay device 30 manages the multicast transfer period for each network that requests the transfer of multicast data. If the request information is not received from the management target network within the multicast transfer period, the data transmitted by multicast is not transferred to the network after the multicast transfer period elapses.
  • the control unit 32 has a second management table for determining whether or not multicast data can be transferred for each network managed by the relay device 30. In the second management table, from the request information from the control device 20, the communication device 41, and the communication device 42, the network address of the transfer destination, the multicast group address to be transferred, the expiration date, and the like are associated.
  • the expiration date is the time when the multicast transfer period ends.
  • the control unit 32 periodically transmits inquiry information and receives the request information from the second communication unit 31, the transfer destination network address, the multicast group address to be transferred, the expiration date, etc. are registered in the second management table. To do.
  • the control unit 32 deletes the request information from the second management table.
  • the control unit 32 receives multicast data from the control device 20 and the communication devices 41 and 42, the control unit 32 checks whether the multicast group address of the transmitted multicast data is an address managed in the second management table. If the control unit 32 determines that the corresponding multicast address group, the control unit 32 transfers the received multicast data to the corresponding network.
  • the relay device 50 is different from the relay device 30 only in that it manages an IP network different from the IP network managed by the relay device 30, and the configuration thereof is the same as that of the relay device 30. To do. An overview of the overall operation of the control system 10, particularly an operation for transmitting request information, will be described with reference to the sequence diagram shown in FIG.
  • the control apparatus 20 transmits request information at the time of starting (step S200). After transmitting the request information in step S200, the control device 20 transmits the request information periodically (for example, every minute) (steps S205 to S215).
  • the relay device 30 transmits inquiry information to the control device 20 and the communication devices 41 and 42 (from step S220 to step S230).
  • Each of the control device 20 and the communication devices 41 and 42 transmits request information as a response to the inquiry information (steps S235 to S245).
  • Each of the control device 20 and the communication devices 41 and 42 transmits the request information as a response to the inquiry information, and then responds to the inquiry information periodically transmitted, thereby enabling multicast communication.
  • the control device 20 transmits request information every minute until the inquiry information is received.
  • the time length of the multicast transfer period managed by the relay device 30 is 5 minutes. For this reason, the control device 20 always transmits the request information within the multicast transfer period. That is, in the communication port management table of the relay device 30, the expiration date of the multicast transfer period at the communication port connected to the control device 20 is constantly updated.
  • the communication processing unit 22 of the control device 20 causes the first communication unit 21 to transmit request information at the time of activation (step S300).
  • the communication processing unit 22 determines whether or not a predetermined time (for example, 1 minute) has elapsed (step S305).
  • the communication processing unit 22 When determining that the predetermined time has elapsed (“Yes” in step S305), the communication processing unit 22 causes the first communication unit 21 to transmit request information (step S310). After the request information is transmitted, the process returns to step S305.
  • the communication processing unit 22 determines whether the first communication unit 21 has received the inquiry information from the relay device 30 (step S315). ). If it is determined that the inquiry information has not been received (“No” in step S315), the process returns to step S305.
  • the communication processing unit 22 transmits the request information to the first communication unit 21 as a response to the inquiry information (step S320), and ends the process.
  • the control device 20 After receiving the inquiry information and transmitting the request information as a response, the processing is completed. Thereby, it turns out that transmission of request information by the 1st communication part 21 performed by Step S305 and Step S310 is stopped regularly (every minute). In the present embodiment, the control device 20 transmits request information every minute until the inquiry information is received.
  • the multicast transfer period managed by the relay device 30 is 5 minutes. For this reason, the control device 20 always transmits the request information within the multicast transfer period. That is, in the communication port management table of the relay device 30, the expiration date of the multicast transfer period at the communication port connected to the control device 20 is constantly updated. Therefore, until the management by the inquiry information is started, the multicast communication is performed. The period is never interrupted.
  • one device is connected to each communication port included in the relay device 30, but in the present embodiment, a plurality of devices are connected to one communication port of the relay device 30.
  • a plurality of devices are connected to a wireless communication port
  • a switching hub is connected to a communication port such as Ethernet (registered trademark)
  • a communication port such as Ethernet (registered trademark)
  • a plurality of devices are connected.
  • the present embodiment will be described focusing on differences from the first embodiment.
  • symbol is attached
  • the control system 10 of the present embodiment includes a control device 20, a relay device 30, and communication devices 41 to 44.
  • the control device 20 and the relay device 30 communicate wirelessly. Further, the control device 20 and the communication devices 41 and 42 communicate wirelessly via the relay device 30.
  • the first frequency band is used in wireless communication between the control device 20 and the relay device 30 and in wireless communication via the relay device 30 between the control device 20 and the communication devices 41 and 42.
  • the relay device 30 and the communication devices 43 and 44 communicate wirelessly. In the wireless communication between the relay device 30 and the communication devices 43 and 44, a second frequency band different from the first frequency band is used.
  • the first communication unit 21 of the control device 20 of the present embodiment illustrated in FIG. 7 performs wireless communication with the relay device 30 using the first frequency band.
  • the first communication unit 21 performs wireless communication with the communication devices 41 and 42 via the relay device 30 using the first frequency band. Specifically, the first communication unit 21 according to the present embodiment wirelessly transmits the request information periodically (every 3 minutes) under the control of the communication processing unit 22.
  • the relay device 30 is a relay device that supports IGMP Snooping. As in the first embodiment, the relay device 30 manages a multicast transfer period (for example, 5 minutes) for a device that requests multicast data. If the request information transmitted from the managed device is not wiretapped (received) within the multicast transfer period, the data transmitted by multicast is not transferred to the communication port to which the device is connected. As illustrated in FIG.
  • the second communication unit 31 of the relay device 30 includes a first transmission / reception unit 37 (communication path) and a second transmission / reception unit 38 (communication path).
  • the 1st transmission / reception part 37 performs radio
  • the first transmission / reception unit 37 controls the request information that has been wiretapped (received) when wiretapping (receiving) the request information transmitted wirelessly using the first frequency band by using IGMP Snooping. To the unit 32.
  • the first transmission / reception unit 37 When the first transmission / reception unit 37 receives multicast data (first data) transmitted from the control device 20 by multicast, the first transmission / reception unit 37 outputs the received first data to the control unit 32.
  • the first transmission / reception unit 37 receives multicast data (second data) transmitted by multicast from the communication devices 41 and 42, the first transmission / reception unit 37 outputs the received second data to the control unit 32.
  • the second transmission / reception unit 38 performs wireless communication with the communication devices 43 and 44 via the antenna 38a using the second frequency band. Specifically, the second transmission / reception unit 38 controls the request information that has been wiretapped (received) when wiretapping (receiving) the request information transmitted wirelessly using the second frequency band using IGMP Snooping. To the unit 32.
  • the second transmission / reception unit 38 When receiving the multicast data (third data) transmitted from the communication devices 43 and 44 by multicast from the communication devices 43 and 44, the second transmission / reception unit 38 outputs the received third data to the control unit 32.
  • the control unit 32 of this embodiment controls the overall operation of the relay device 30.
  • the control unit 32 has a frequency band management table for determining whether or not multicast transfer is possible for each frequency band used for radio. In the frequency band management table, a band identifier for identifying a frequency band in which multicast transmission is possible among the first transmission / reception unit 37 and the second transmission / reception unit 38 is associated with an expiration date.
  • the expiration date is the time when the multicast transfer period ends.
  • the control unit 32 adds a time (for example, 5 minutes) that is a multicast transfer period to the received time, and calculates an expiration date.
  • the control unit 32 specifies whether the output source of the received request information is the first transmission / reception unit 37 or the second transmission / reception unit 38.
  • the control unit 32 determines whether or not a band identifier for identifying a frequency band used by the specified transmission / reception unit 39 (the first transmission / reception unit 37 or the second transmission / reception unit 38) is registered in the frequency band management table.
  • the band identifier of the frequency band used by the specified transmission / reception unit 39 is associated with the expiration date and registered in the frequency band management table. If registered, the expiration date associated with the band identifier is updated to the calculated expiration date.
  • the control unit 32 deletes the band identifier and the expiration date from the frequency band management table.
  • the control unit 32 uses the frequency band management table to transmit one or more multicast data.
  • the transmission / reception unit 39 is specified.
  • the control unit 32 uses the frequency band management table to identify one or more transmission / reception units 39 that can transfer the multicast data.
  • the control unit 32 causes the specified one or more transmission / reception units 39 to transmit multicast data.
  • the control unit 32 receives data that is not any of the first to third data, that is, receives data of a multicast address group that is not managed by multicast transfer, the control unit 32 does not transfer the data.
  • the control unit 32 of the present embodiment determines whether multicast communication is possible for each frequency band used for wireless communication. That is, the frequency band can be regarded as a concept similar to the communication port connected to the cable described in the first embodiment.
  • the overall operation of the control system 10 according to the present embodiment is made by connecting a plurality of devices to one communication port included in the relay device 30.
  • the only difference is that there is no change in the processing content. Therefore, the description about the operation
  • the operation of the control device 20 of the present embodiment differs from the first embodiment only in that a plurality of devices are connected to one communication port provided in the relay device 30. There is no change in the processing content. Therefore, the description of the operation of the control device 20 of the present embodiment is also omitted.
  • the relay device 30 determines whether multicast communication is possible for each frequency band used for wireless communication. Therefore, when the relay device 30 receives the request information from the control device (for example, the control device 20) that uses one frequency band, the relay device 30 sends it to other devices (here, the communication devices 41 and 42) that use the one frequency band. Also, multicast communication is possible. That is, bidirectional multicast communication is possible between the control device 20 and the communication devices 41 and 42. 4 Embodiment 4 In the first embodiment, the multicast transfer period managed by the relay apparatus 30 is uniformly 5 minutes. However, in this embodiment, the multicast transfer period is different for each model (manufacturer) of the relay apparatus 30. .
  • the control device 20 acquires information on the multicast transfer period managed by the relay device 30 using the MAC address of the relay device 30, and transmits request information based on the acquired information on the multicast transfer period. Determine the transmission cycle.
  • the control device 20 of the present embodiment further includes a storage unit 23.
  • the storage unit 23 stores a transfer period management table in which a manufacturer of a relay apparatus is associated with a multicast transfer period managed by the relay apparatus.
  • the MAC address is represented by 12 digits using a hexadecimal number. Of the 12 digits, the first six digits represent the manufacturer. Therefore, the storage unit 23 also stores a manufacturer management table in which the manufacturer is associated with the first six digits of the MAC address.
  • the first communication unit 21 transmits an address request for requesting a MAC address to the relay device 30 under the control of the communication processing unit 22, and then receives the MAC address from the relay device 30.
  • the communication processing unit 22 controls the first communication unit 21 so that the first communication unit 21 transmits an address request and receives a MAC address.
  • the communication processing unit 22 specifies the multicast transfer period managed by the relay device 30 using the MAC address, the manufacturer management table, and the transfer period management table.
  • the communication processing unit 22 controls the first communication unit 21 to transmit the request information by using the time length of the specified multicast transfer period or a time length shorter than the time length as a transmission cycle.
  • An overall operation outline of the control system 10 of the present embodiment, particularly an operation for determining a transmission cycle of request information will be described with reference to a sequence diagram shown in FIG.
  • the first communication unit 21 of the control device 20 receives data including, for example, a management protocol from the relay device 30 (step S400).
  • the communication processing unit 22 of the control device 20 specifies the manufacturer of the relay device 30 from the MAC address included in the received data (step S405). Specifically, the communication processing unit 22 searches the manufacturer management table stored in the storage unit 23 for a numerical value that matches the first six digits of the MAC address included in the received data. If there is a matching numerical value, information on the manufacturer associated with the numerical value is acquired.
  • the communication processing unit 22 specifies the multicast transfer period managed by the relay device 30 from the specified manufacturer (step S410). Specifically, the communication processing unit 22 searches the transfer period management table stored in the storage unit 23 for a manufacturer that matches the specified manufacturer. If there is a matching manufacturer, the multicast transfer period associated with the manufacturer is specified.
  • the communication processing unit 22 determines the time length of the specified multicast transfer period or a time length shorter than the time length as the request information transmission cycle (step S415).
  • the first communication unit 21 transmits the request information at the determined transmission cycle (steps S420 and S425).
  • the operation of the control device 20, particularly the operation for determining the transmission period of request information and transmitting the request information will be described with reference to the flowchart shown in FIG.
  • the communication processing unit 22 of the control device 20 acquires the MAC address included in the data received by the first communication unit 21 (step S500).
  • the communication processing unit 22 specifies the manufacturer of the relay device 30 using the acquired MAC address and manufacturer management table (step S505).
  • the communication processing unit 22 specifies the multicast transfer period managed by the relay device 30 using the specified manufacturer and transfer period management table (step S510).
  • the communication processing unit 22 determines a time length that is the same as the time length of the specified multicast transfer period or a time length shorter than the time length as a transmission cycle (step S515).
  • the communication processing unit 22 causes the first communication unit 21 to transmit request information (step S520).
  • the communication processing unit 22 determines whether or not the determined transmission cycle has elapsed (step S525). When determining that the time has elapsed (“Yes” in step S525), the communication processing unit 22 causes the first communication unit 21 to transmit request information (step S530). After the request information is transmitted, the process returns to step S525.
  • the communication processing unit 22 waits for the transmission cycle to elapse. Accordingly, the control device 20 periodically transmits the request information so that the multicast communication period is not interrupted even when the multicast transfer period is different for each manufacturer of the relay device 30. Can do.
  • the multicast transfer period and the manufacturer of the relay device 30 are stored in association with each other, but the present invention is not limited to this.
  • the multicast transfer period and the model number of the relay device 30 may be stored in association with each other. That is, the control device 20 only needs to store the multicast transfer period and the information for identifying the relay device 30 in association with each other.
  • storage part 23 was provided with the control apparatus 20, it is not limited to this.
  • the storage unit 23 may be connected to the control device 20 via a network.
  • the configurations of Embodiments 2 to 4 can be applied even if they are combined with each other.
  • Embodiment 5 In the first embodiment, the transmission cycle for transmitting the request information is fixed (for example, 3 minutes). However, the present embodiment is different in that the transmission cycle of the request information can be dynamically shortened. In the following, the present embodiment will be described focusing on differences from the first embodiment.
  • symbol is attached
  • the communication processing unit 22 transmits the request information at a predetermined transmission cycle.
  • the communication processing unit 22 transmits / receives data to / from the communication devices 41 and 42 via the relay device 30 to determine whether or not the transmission cycle needs to be shortened.
  • the transmitted / received data is, for example, an ECHONET Lite Get request, Get response, INF request, and INF response.
  • the communication processing unit 22 determines the currently determined transmission cycle to be a shorter transmission cycle.
  • the control device 20 transmits the request information to the relay device 30 (step S600).
  • the control device 20 performs a multicast transfer detection process (step S605). Specifically, the control device 20 transmits a Get request (Get_Request) requesting data (unicast data) transmitted by unicast to the communication device 41 via the relay device 30 (steps S610 and S615).
  • the control device 20 receives the Get response (Get_Response) transmitted by the communication device 41 via the relay device 30 (steps S620 and S625).
  • the control device 20 transmits an INF request (INF_Request) for requesting multicast data to the communication device 41 via the relay device 30 (steps S630 and S6). 35).
  • the control device 20 receives the INF response (INF) transmitted by the communication device 41 via the relay device 30 (steps S640 and S645).
  • the GET request, GET response, and INF request are unicast data, and the INF response is multicast data.
  • the Get request corresponds to unicast data request information
  • the INF request corresponds to multicast data request information.
  • the predetermined time T0 is a time obtained by subtracting the processing time length ⁇ T of the multicast transfer detection process from the transmission cycle T1.
  • the control device 20 transmits the request information to the relay device 30 when determining that the predetermined time T1 (T11) has elapsed since the request information was transmitted in step S600 (step S650).
  • the relay device 30 has shortened the time length (transfer permission time) of the multicast transfer period managed by the relay device 30 (step S655).
  • the shortened transfer permission time T2 is shorter than the transmission cycle T1.
  • the relay device 30 discards the management information (step S660).
  • the control device 20 When a predetermined time T0 (T02) has elapsed since the request information was transmitted in step S650, the control device 20 performs a multicast transfer detection process (step S665). Specifically, as described above, the control device 20 transmits a Get request, receives a Get response, and transmits an INF request (Steps S670 to S695). Since the relay device 30 discards the management information, the multicast data is not transferred. For this reason, the INF response transmitted by the communication device 41 in step S700 cannot be received. Since the control device 20 does not receive the INF response in the multicast transfer detection process performed in step S665, the control device 20 shortens the request information transmission cycle (step S705) and transmits the request information to the relay device 30 (step S710).
  • the control device 20 When the predetermined time T4 has elapsed since the request information was transmitted in step S710, the control device 20 performs a multicast transfer detection process (step S715).
  • the predetermined time T4 is a time obtained by subtracting ⁇ T from the shortened transmission cycle T3.
  • the control device 20 transmits the request information to the relay device 30 at a transmission cycle corresponding to the result of the multicast transfer detection process (step S720).
  • the transmission cycle T11 and the transmission cycle T12 are depicted as being different from each other for convenience of explanation, but are actually the same cycle.
  • the predetermined times T01 and T02 and the transfer permission times T21 and T22 are depicted as different in the drawing, they are actually the same time length.
  • each ⁇ T described in FIG. 11 is also drawn so that these time lengths are different for convenience of explanation, but in actuality, they are the same time length.
  • the communication processing unit 22 of the control device 20 causes the first communication unit 21 to transmit request information at the time of activation (step S750).
  • the communication processing unit 22 determines whether a predetermined time has elapsed (step S755).
  • the predetermined time is a time obtained by subtracting the processing time length ⁇ T of the multicast transfer detection process from the transmission period of the request information.
  • step S760 the communication processing unit 22 performs a multicast transfer detection process. Specifically, the communication processing unit 22 transmits a Get request and determines whether unicast data (Get response) is received as a response (Step S765). If it is determined that unicast data has been received (“Yes” in step S765), the communication processing unit 22 transmits an INF request and determines whether multicast data (INF response) has been received as a response (step S765). Step S770). When determining that the multicast data has not been received (“No” in step S770), the communication processing unit 22 shortens the transmission cycle of the request information (step S775).
  • the control device 20 shortens the request information transmission cycle in order to prevent the management information from being discarded.
  • the communication processing unit 22 ends the process.
  • the communication processing unit 22 sends the request information to the first communication unit 21 when determining that the transmission cycle has elapsed since the previous request information was transmitted. Transmit (step S780). After the request information is transmitted, the process returns to step S755.
  • the communication processing unit 22 causes the first communication unit 21 to transmit the request information (Step S780). After the request information is transmitted, the process returns to step S755. In this case, the communication processing unit 22 controls the first communication unit 21 to transmit the request information with a shortened transmission cycle. If it is determined that the predetermined time has not elapsed (“No” in step S755), the process waits for the elapse of the predetermined time. As a result, even when the time length of the multicast transfer period of the relay device 30 is shortened, the control device 20 periodically transmits the request information so that the period during which communication by multicast is possible is not interrupted. can do.
  • the control device 20 transmits the request information at an optimal transmission cycle in which the management information is not discarded by repeating the multicast transfer detection process. be able to. That is, the control device 20 can transmit the request information with the same length as the time length of the multicast transfer period (transfer permission time) of the relay device 30 or a time length shorter than the transfer permission time as a transmission cycle.
  • a combination of a function for causing the communication processing unit 22 to transmit request information to the first communication unit 21 and a function for performing a multicast forwarding detection process corresponds to a response detection process. Normally, transmission / reception of unicast data is performed regardless of control of multicast data transfer by the relay device 30.
  • the process is terminated when unicast data is not received.
  • the control device 20 may notify the user of an error message indicating that the relay device 30 has a problem.
  • the multicast transfer detection process is performed every transmission period of request information, but the present invention is not limited to this. When multicast data (INF response) is received by the control device 20 by the multicast transfer detection process, it is not necessary to perform the subsequent multicast transfer detection process every time the request information is transmitted.
  • the subsequent multicast transfer detection process may be performed in units of one day, one week, or one month.
  • the control device 20 shortens the transmission period of the request information, and multicast transmission every time the request information is transmitted until multicast data is received. Repeat the detection process.
  • the control device 20 does not perform the subsequent multicast transfer detection process every time the request information is transmitted, but in units such as one day, one week, or one month. .
  • the multicast transfer detection process is performed using only the communication device 41.
  • the multicast transfer detection process may be performed on each communication device.
  • the Get request (unicast data request information) is data transmitted by unicast, but the present invention is not limited to this.
  • the Get request may be transmitted by broadcast.
  • the Get request is transmitted by broadcast, there is a disadvantage that there is no guarantee that the Get request is received by all the communication devices 41 and 42.
  • the control device 20 may not receive all Get responses.
  • a Get request can be delivered to a plurality of communication devices 41 and 42 by a single transmission.
  • the control device 20 may switch between transmission by unicast and transmission by broadcast according to the number of communication devices that transmit a Get request.
  • the control device 20 stores the number of communication devices to be communicated.
  • the communication processing unit 22 selects transmission by unicast if the number of stored communication devices is less than the threshold, and selects transmission by broadcast if the number of stored communication devices is equal to or greater than the threshold. .
  • the communication processing unit 22 may select transmission by unicast or transmission by broadcast by a user operation. In addition, when the transmission by broadcast is selected, the communication processing unit 22 may cause the first communication unit 21 to repeat the Get request transmission a plurality of times. For example, when the control device 20 and the communication devices 41 and 42 are communicating wirelessly via the relay device 30, a communication device that cannot receive a Get response or a Get response is sent to the relay device 30 depending on radio wave conditions. There may be communication devices that do not reach. Therefore, the communication processing unit 22 can improve the accuracy of confirmation of the Get response to the Get request transmitted by broadcasting by causing the first communication unit 21 to transmit the Get request multiple times by broadcasting.
  • the communication processing unit 22 may cause the first communication unit 21 to repeatedly transmit an INF request (multicast data request information) a plurality of times by multicast. Thereby, the accuracy of confirmation of the INF response to the INF request transmitted by multicast can be improved. Further, the configurations of the second to fifth embodiments can be applied even when combined with each other. 6 Embodiment 6 In the fifth embodiment, a request information transmission cycle is determined by including a multicast data transfer detection process in a normal process for periodically transmitting request information. This embodiment is different from the fifth embodiment in that a process for determining the transmission cycle of request information is performed separately from the normal process. In the following, the present embodiment will be described focusing on differences from the fifth embodiment.
  • the communication processing unit 22 transmits the request information to the first communication unit 21 at the time of activation, and performs the above-described multicast transfer detection process when a predetermined time has elapsed since the transmission of the request information.
  • the predetermined time is, for example, a transmission cycle set at the present time.
  • the communication processing unit 22 shortens the predetermined time when multicast data (INF response) is not received.
  • the communication processing unit 22 performs the request information transmission and the multicast transfer detection process described above until the multicast data (INF response) is received.
  • the communication processing unit 22 sets a predetermined time set at that time as a transmission cycle.
  • the communication processing unit 22 controls the first communication unit 21 to transmit the request information at the determined transmission cycle.
  • the communication processing unit 22 performs a process (determination process) for periodically determining whether multi-data can be received from the communication devices 41 and 42, and determines that the multi-data cannot be received in the determination process.
  • the transmission cycle is determined in the same manner as when starting up.
  • the control device 20 When a predetermined time T5 has elapsed since the request information was transmitted in step S600, the control device 20 performs a multicast transfer detection process (step S805). Specifically, the control device 20 controls the first communication unit to transmit a Get request (Get_Request) for requesting unicast data to the communication device 41 via the relay device 30 (steps S810 and S815). The control device 20 controls the first communication unit 21 to receive the Get response (Get_Response) transmitted by the communication device 41 via the relay device 30 (steps S820 and S825). The control device 20 controls the first communication unit 21 to transmit an INF request (INF_Request) for requesting multicast data to the communication device 41 via the relay device 30 (steps S830 and S835).
  • INF_Request INF request
  • the Get request corresponds to unicast data request information
  • the INF request corresponds to multicast data request information.
  • the control device 20 cannot receive the INF response (INF) from the communication device 41 (step S840).
  • the control device 20 shortens the predetermined time T5 (step S845).
  • the predetermined time after shortening is described as T6.
  • the control device 20 shortens the request information transmission cycle in order to prevent the management information from being discarded.
  • the control device 20 transmits the request information to the relay device 30 (step S850).
  • the control device 20 performs a multicast transfer detection process (step S855). Specifically, as described above, the control device 20 controls the first communication unit to transmit a Get request, receive a Get response, and transmit an INF request (Steps S860 to S890).
  • the control device 20 receives the INF response from the communication device 41 by shortening the predetermined time (steps S890 and S895).
  • the communication processing unit 22 of the control device 20 causes the first communication unit 21 to transmit request information at the time of activation (step S900).
  • the communication processing unit 22 determines whether or not a predetermined time (T5) has elapsed (step S905). If it is determined that a predetermined time has elapsed since the request information was transmitted (“Yes” in step S905), the communication processing unit 22 performs a multicast transfer detection process (step S910). Specifically, the communication processing unit 22 transmits a Get request to the first communication unit 21, and determines whether or not the first communication unit 21 has received unicast data (Get response) as a response (Step). S915).
  • the communication processing unit 22 causes the first communication unit 21 to transmit an INF request, and whether multicast data (INF response) has been received as a response. It is determined whether or not (step S920).
  • the communication processing unit 22 determines the predetermined time set at the present time as the transmission cycle (step S925). The communication processing unit 22 controls the first communication unit 21 so as to transmit the request information at the determined transmission cycle.
  • the communication processing unit 22 shortens the predetermined time (step S930) and causes the first communication unit 21 to transmit the request information (step S935).
  • step S905 the determination process in step S905 is performed using the shortened predetermined time. If it is determined that the predetermined time has not elapsed (“No” in step S905), the process waits for the elapse of the predetermined time. 13 and 14, the control device 20 determines the transmission cycle at the time of activation. However, also when it is detected by the above-described determination process that multicast data cannot be received, the control device 20 can determine the transmission cycle in the same process flow. Thereby, the control apparatus 20 can determine the transmission period of request information so that the communicable period by multicast may not be interrupted.
  • the control device 20 may notify the user of an error message indicating that the relay device 30 is defective. Also in the present embodiment, as in the fifth embodiment, the Get request may be transmitted by broadcast. 7 Embodiment 7
  • a control system 10 in which the fifth embodiment and the sixth embodiment are combined will be described. First, a case will be described in which a relay device 30 is newly installed in the control system 10 of the present embodiment or an existing relay device is replaced with a new relay device 30. In this case, since the control device 20 has not acquired any information about the new relay device 30, the control device 20 has not acquired any information on the multicast transfer period set in the relay device 30.
  • the control device 20 sets the transmission cycle so that the transmission cycle of the request information is equal to or less than the time length of the multicast transfer period of the new relay device 30. It is necessary to decide. Therefore, in the present embodiment, the control device 20 performs the process (determination process) for determining the request information transmission cycle described in the sixth embodiment before the periodic transmission of the request information. Specifically, the communication processing unit 22 of the control device 20 first transmits request information to the first communication unit 21 as shown in step S900 of FIG. The communication processing unit 22 performs multicast transfer detection processing when a predetermined time stored in advance in the control device 20 has elapsed (see step S910 in FIG. 14).
  • the communication processing unit 22 shortens the predetermined time and transmits the request information to the first communication unit 21 again (steps S930 and S935 in FIG. 14). reference).
  • the communication processing unit 22 determines a predetermined time set at that time as a transmission cycle. As a result, even when the control device 20 has not acquired information on the multicast transfer period set by the new relay device 30, the transmission cycle is set to be equal to or less than the time length of the multicast transfer period of the relay device 30. Can be determined.
  • the control device 20 transmits the request information at the transmission cycle determined by the determination process described above.
  • the communication processing unit 22 periodically transmits request information to the first communication unit 21 based on the process illustrated in FIG. Specifically, the communication processing unit 22 first transmits request information to the first communication unit 21 as shown in step S750 of FIG. After transmitting the request information, the communication processing unit 22 performs a multicast transfer detection process when a predetermined time has elapsed.
  • the predetermined time here is a time obtained by subtracting the processing time length (for example, ⁇ T) of the multicast forwarding detection process from the transmission cycle (for example, T1) as described in the fifth embodiment.
  • the transmission cycle is shortened and the request information is transmitted again to the first communication unit 21 (see steps S775 and S780 in FIG. 12).
  • the communication processing unit 22 causes the first communication unit 21 to transmit subsequent request information at the transmission cycle set at that time. Thereby, the control apparatus 20 can shorten a transmission period, even after a transmission period is determined by the determination process. Further, as described in the fifth embodiment, in this embodiment as well, it is not necessary to perform the multicast transfer detection process for each request information transmission cycle.
  • the subsequent multicast transfer detection process is performed one day later, one week later, or 1 It may be done in units such as months later.
  • the control device 20 shortens the transmission period of the request information, and multicast transmission every time the request information is transmitted until multicast data is received. Repeat the detection process.
  • the control device 20 does not perform the subsequent multicast transfer detection process every time the request information is transmitted, but in units such as one day, one week, or one month. .
  • the Get request may be transmitted by broadcast.
  • the control device 20 periodically transmits the request information.
  • the control information is also periodically transmitted to request the request information to be transmitted to the relay device 30.
  • the point of sending is different.
  • the inquiry information is, for example, IGMP Query as described above.
  • the present embodiment will be described focusing on differences from the first embodiment.
  • symbol is attached
  • the first communication unit 21 transmits inquiry information to the communication devices 41 and 42 via the relay device 30 under the control of the communication processing unit 22.
  • the inquiry information may be transmitted at the same timing as the request information is transmitted to the relay device 30 or at a different timing.
  • the communication processing unit 22 controls the first communication unit 21 so as to transmit inquiry information (IGMP Query) by multicast.
  • the IGMP Query is stipulated in the IGMP standard so that multicast transmission is performed in the relay device even for communication ports that are not permitted to transfer multicast data. Therefore, in this embodiment, when the relay apparatus 30 transmits inquiry information (IGMP Query), the received inquiry information is transferred to the communication ports 34 and 35 to which the communication apparatuses 41 and 42 are connected.
  • the communication apparatuses 41 and 42 can receive inquiry information.
  • the communication devices 41 and 42 receive the inquiry information and wish to receive multicast data addressed to a specific group
  • the communication devices 41 and 42 send request information (IGMP Report) including the multicast address desired to be received to the control device 20 to the relay device 30.
  • request information IGMP Report
  • the control unit 32 of the relay device 30 transmits the inquiry information to the communication devices 41 and 42.
  • the control unit 32 acquires the multicast address included in the request information by IGMP Snooping, the control unit 32 permits the communication port that has received the request information to transfer multicast data until the multicast transfer period elapses.
  • the control device 20 transmits inquiry information to the communication devices 41 and 42 via the relay device 30 at the time of activation (steps S1000 to S1010).
  • the communication devices 41 and 42 that have received the inquiry information transmit request information to the relay device 30 as a response to the inquiry information when they wish to receive multicast data addressed to a specific group (steps S1015 and S1020).
  • the control device 20 transmits the request information to the relay device 30 (step S1025).
  • the control device 20 transmits inquiry information to the communication devices 41 and 42 via the relay device 30 (steps S1030 to S1040).
  • the communication devices 41 and 42 that have received the inquiry information transmit request information to the relay device 30 if they wish to receive multicast data addressed to a specific group (steps S1045 and S1050).
  • the control device 20 transmits the request information to the relay device 30 (step S1055).
  • the control device 20 transmits inquiry information to the communication devices 41 and 42 via the relay device 30 (steps S1060 to S1070). .
  • the communication devices 41 and 42 that have received the inquiry information transmit request information to the relay device 30 when they wish to receive multicast data addressed to a specific group (steps S1075 and S1080). After transmitting the inquiry information, the control device 20 transmits the request information to the relay device 30 (step S1085).
  • the communication processing unit 22 of the control device 20 causes the first communication unit 21 to transmit inquiry information and request information at the time of activation (steps S1100 and S1105).
  • the communication processing unit 22 determines whether a predetermined time has elapsed (step S1110).
  • the predetermined time is a request information transmission cycle.
  • the communication processing unit 22 When determining that the predetermined time has passed (“Yes” in step S1110), the communication processing unit 22 causes the first communication unit 21 to transmit inquiry information and request information (steps S1115 and S1120). After the inquiry information and request information are transmitted, the process returns to step S1110. If it is determined that the predetermined time has not elapsed (“No” in step S1110), the process waits for the elapse of the predetermined time. As described above, the control device 20 transmits the request information to the communication devices 41 and 42 connected to different communication ports in the relay device 30 by periodically transmitting the inquiry information. Therefore, the relay device 30 can transfer multicast data not only to the control device 20 but also to the communication devices 41 and 42.
  • control apparatus 20 transmitted inquiry information as multicast data, when the information of the address of the communication apparatuses 41 and 42 is acquired, you may transmit as unicast data. Or the control apparatus 20 may transmit inquiry information by broadcast. 9 Other variations, although the present invention has been described based on the first to sixth embodiments, the present invention is not limited to the above-described embodiments. For example, the following modifications can be considered. (1) In the above embodiments, only the control device 20 transmits the request information. However, the present invention is not limited to this. The communication devices 41 and 42 may also periodically send request information. (2) In the first embodiment, each of the communication ports 33 to 35 is connected to one device (the control device 20, the communication devices 41 and 42), but is not limited thereto.
  • At least one of the communication ports 33 to 35 may be connected to another relay device.
  • the relay device 30 can transmit multicast data to one or more devices connected to other relay devices.
  • the number of communication ports is three in the first embodiment, the present invention is not limited to this.
  • the number of communication ports may be two or more.
  • the two frequency bands used for the wireless communication are the first frequency band and the second frequency band.
  • the present invention is not limited to this.
  • One or more frequency bands may be used for wireless communication.
  • the second communication unit 31 includes a transmission / reception unit according to the number of frequency bands used for wireless communication, for example.
  • the control device 20 starts the periodic transmission of request information at the time of activation, but is not limited to this.
  • the communication processing unit 22 of the control device 20 may start periodic transmission of the request information when the next inquiry information is not received within a predetermined time (for example, within 5 minutes). .
  • the relay device 30 may periodically output inquiry information (IGMP Query). In this case, until the inquiry information is received from the relay device 30, the control device 20 transmits the request information to the relay device 30 periodically (for example, every 3 minutes) as in the first embodiment.
  • the control device 20 transmits the request information to the relay device 30, and then stops transmitting the request information periodically.
  • the control device 20 communicates with the one or more communication devices 41 and 42 to be controlled via the relay device 30 and controls the one or more communication devices 41 and 42.
  • the relay device 30 permits the transfer of data to the communication path that has received the request information after receiving the request information for requesting the transfer of the data transmitted by multicast until the end of the multicast transfer period.
  • the communication path is, for example, the communication ports 33 to 35, the first transmission / reception unit 37, and the second transmission / reception unit 38.
  • the control device 20 includes a first communication unit 21 (communication unit) that performs communication with the relay device 30 and communication with one or more communication devices 41 and 42 via the relay device 30, and a communication processing unit 22. Prepare.
  • the communication processing unit 22 causes the first communication unit 21 to transmit the request information within the multicast transfer period.
  • the control device 20 transmits the request information within the multicast transfer period.
  • a device control device 20 having higher processing performance than other devices (communication devices 41 and 42) controls the other devices. Therefore, even if the control device 20 periodically transmits the request information within the multicast transfer period, the processing load is low compared to the case where the other device performs. That is, the control device 20 can perform multicast communication while preventing a decrease in reliability of the entire system.
  • the control device 20 includes a storage unit that stores identification information for identifying the relay device 30 and a multicast transfer period in association with each other.
  • the first communication unit 21 receives identification information (a numerical value of the first six digits of the MAC address) for identifying the relay device 30.
  • the communication processing unit 22 specifies the multicast transfer period corresponding to the identification information received by the first communication unit 21 and causes the first communication unit 21 to transmit the request information within the specified multicast transfer period.
  • the control device 20 can periodically transmit the request information so that the multicast communication period is not interrupted even when the multicast transfer period is different for each relay device 30.
  • the communication processing unit 22 performs a response detection process. In the response detection process, request information is transmitted to the first communication unit 21, and when a predetermined time has elapsed, at least one of the one or more communication devices 41 and 42 is requested to send multicast data.
  • the communication processing unit 22 performs a response detection process by shortening the predetermined time.
  • the communication processing unit 22 controls the first communication unit 21 to transmit the request information at a transmission period corresponding to a predetermined time set at that time. According to this configuration, since the control device 20 dynamically shortens the transmission period of the request information, the request information is periodically updated so that the multicast communication period is not interrupted according to the multicast transfer period of the relay device 30. Can be transmitted.
  • the communication processing unit 22 transmits unicast data request information for requesting transmission of unicast data to at least one communication device among the one or more communication devices 41 and 42. 21 to transmit.
  • the communication processing unit 22 shortens the predetermined time when the first communication unit 21 receives unicast data and does not receive multicast data.
  • the control device 20 can shorten the transmission cycle only when the relay device 30 controls the transfer of data transmitted by multicast to the communication path. This is because, normally, when the control device 20 cannot receive both unicast data and multicast data, a failure of the relay device 30 itself can be considered.
  • the communication processing unit 22 further transmits inquiry information for requesting transmission of the request information to the relay device 30 to the first communication unit 21 within one multicast transmission period to one or more communication devices 41 and 42. It is preferable to make it.
  • the control device 20 can transfer multicast data not only to the device itself but also to other devices (communication devices 41 and 42) that request the transfer of multicast data.
  • the first communication unit 21 preferably performs communication with the relay device 30 and communication with the one or more communication devices 41 and 42 via the relay device 30 by wireless communication using a frequency band.
  • the relay device 30 controls transfer of data transmitted by multicast using a radio path using a frequency band as a communication path.
  • the control device 20 can transmit the request information to the relay device 30 by wireless communication.
  • the relay device 30 enables multicast data to be transferred to the communication devices 41 and 42 that use the same frequency band as that used by the control device 20 in wireless communication. That is, bidirectional multicast communication is possible between the control device 20 and the communication devices 41 and 42.
  • the program of the present application is a program for causing a computer to function as any one of the control devices 20 described above. According to this program, multicast communication can be performed while preventing a decrease in the reliability of the entire system.

Abstract

Provided is a control device capable of multicast communication while preventing degradation in the reliability of the entire system. A control device 20 communicates with communication devices 41, 42 to be controlled via a relay device 30, and controls the communication devices 41, 42. During a period from the reception of request information requesting transfer of data transmitted by multicasting to the end of a multicast transfer period, the relay device 30 permits a communication path which has received the request information to transfer the data. The control device 20 is provided with a first communication unit 21 which performs communication with the relay device 30 and communication with one or more communication devices 41, 42 via the relay device 30, and a communication processing unit 22 which causes the first communication unit 21 to transmit the request information within the multicast transfer period.

Description

制御装置およびプログラムControl device and program
 本発明は、一般に制御装置およびプログラム、より詳細にはマルチキャストによる通信を行う制御装置およびプログラムに関する発明である。 The present invention generally relates to a control device and a program, and more specifically to a control device and a program that perform communication by multicast.
 近年、マルチキャストでの通信、例えば多宛先メッセージを送信するための技術が開示されている(日本国特許第3895685号明細書参照)。
 マルチキャストとは、複数の装置に対して、1回の送信で複数の装置にデータを到達させるための技術である。
 マルチキャストでは、装置間に介在するルータに、多宛先メッセージの転送を要求するための情報を送信する。
 特許文献1では、複数の装置からなるグループ(多宛先グループ)の代表装置が、多宛先メッセージの転送を要求するための情報に相当する存在信号を、中継装置(ルータ)に相当するグループ制御ユニットに定期的に送信している。そして、多宛先メッセージがグループ制御ユニットで受信されると、多宛先メッセージが、グループに属する全ての装置に転送される。
2. Description of the Related Art Recently, a technique for transmitting multicast communication, for example, a multi-destination message has been disclosed (see Japanese Patent No. 3895685).
Multicast is a technique for allowing data to reach a plurality of devices in a single transmission.
In multicast, information for requesting transfer of a multi-destination message is transmitted to a router interposed between devices.
In Patent Document 1, a representative device of a group (multi-destination group) composed of a plurality of devices sends a presence signal corresponding to information for requesting transfer of a multi-destination message to a group control unit corresponding to a relay device (router). Send regularly to. When the multi-destination message is received by the group control unit, the multi-destination message is transferred to all devices belonging to the group.
 特許文献1で記載された技術では、多宛先グループの代表装置として、多宛先グループの他の装置と比べて性能が低い装置が割り当てられる場合がある。
 性能が低い装置が、代表装置に割り当てられると、当該装置が本来実行すべき処理に加えて、存在信号を一定の周期で送信するという処理も行わなければならない。そうすると、当該装置の処理負荷が高くなり、システム全体としての信頼性が低下する。
 そこで、本発明は、上記事由に鑑みてなされており、その目的は、システム全体の信頼性の低下を防ぎつつ、マルチキャストの通信ができる制御装置およびプログラムを提供することにある。
課題を解決するための手段
 本発明の制御装置は、マルチキャストで送信されたデータの転送を依頼する依頼情報を受信してからマルチキャスト転送期間が終了するまでの間は当該依頼情報を受信した通信経路に対して前記データの転送を許可する中継装置を介して、制御対象である1つ以上の通信装置と通信し、前記1つ以上の通信装置の制御を行う制御装置であって、前記中継装置との通信、および前記中継装置を介した前記1つ以上の通信装置との通信を行う通信部と、通信処理部とを備え、前記通信処理部は、前記依頼情報を前記マルチキャスト転送期間内に前記通信部に送信させることを特徴とする。
 また、本発明のプログラムは、コンピュータを、上記制御装置として機能させるためのプログラムである。
発明の効果
 本発明は、システム全体の信頼性の低下を防ぎつつ、マルチキャストの通信ができるという効果を奏する。
In the technique described in Patent Document 1, there is a case where a device having lower performance than other devices in the multi-destination group is assigned as a representative device of the multi-destination group.
When a device with low performance is assigned to a representative device, in addition to the processing that the device should originally execute, processing of transmitting a presence signal at a certain period must also be performed. As a result, the processing load of the apparatus increases, and the reliability of the entire system decreases.
Therefore, the present invention has been made in view of the above reasons, and an object of the present invention is to provide a control device and a program capable of multicast communication while preventing a decrease in reliability of the entire system.
Means for Solving the Problems The control device according to the present invention provides a communication path for receiving the request information after receiving the request information for requesting transfer of data transmitted by multicast until the end of the multicast transfer period. A control device that communicates with one or more communication devices to be controlled via a relay device that permits transfer of the data, and controls the one or more communication devices, the relay device And a communication processing unit that communicates with the one or more communication devices via the relay device, and the communication processing unit includes the request information within the multicast transfer period. Transmitting to the communication unit.
The program of the present invention is a program for causing a computer to function as the control device.
Advantages of the Invention The present invention has an effect that multicast communication can be performed while preventing a decrease in reliability of the entire system.
実施形態1の制御システムおよび制御装置の構成を説明する図である。It is a figure explaining the structure of the control system of Embodiment 1, and a control apparatus. 実施形態1の制御システムの動作概要を説明するシーケンス図である。It is a sequence diagram explaining the operation | movement outline | summary of the control system of Embodiment 1. FIG. 実施形態1の制御装置の動作を説明する流れ図である。3 is a flowchart illustrating the operation of the control device according to the first embodiment. 実施形態2の制御システムおよび制御装置の構成を説明する図である。It is a figure explaining the structure of the control system of Embodiment 2, and a control apparatus. 実施形態2の制御システムの動作概要を説明するシーケンス図である。It is a sequence diagram explaining the operation | movement outline | summary of the control system of Embodiment 2. 実施形態2の制御装置の動作を説明する流れ図である。6 is a flowchart for explaining the operation of the control device according to the second embodiment. 実施形態3の制御システムおよび制御装置の構成を説明する図である。It is a figure explaining the structure of the control system of Embodiment 3, and a control apparatus. 実施形態4の制御システムおよび制御装置の構成を説明する図である。It is a figure explaining the structure of the control system of Embodiment 4, and a control apparatus. 実施形態4の制御システムの動作概要を説明するシーケンス図である。FIG. 10 is a sequence diagram illustrating an operation outline of a control system according to a fourth embodiment. 実施形態4の制御装置の動作を説明する流れ図である。10 is a flowchart for explaining the operation of the control device according to the fourth embodiment. 実施形態5の制御システムの動作概要を説明するシーケンス図である。FIG. 10 is a sequence diagram for explaining an operation outline of a control system according to a fifth embodiment. 実施形態5の制御装置の動作を説明する流れ図である。10 is a flowchart for explaining the operation of the control device of the fifth embodiment. 実施形態6の制御システムの動作概要を説明するシーケンス図である。FIG. 10 is a sequence diagram illustrating an outline of operation of a control system according to a sixth embodiment. 実施形態6の制御装置の動作を説明する流れ図である。14 is a flowchart for explaining the operation of the control device of the sixth embodiment. 実施形態8の制御システムの動作概要を説明するシーケンス図である。FIG. 10 is a sequence diagram for explaining an operation outline of a control system according to an eighth embodiment. 実施形態8の制御装置の動作を説明する流れ図である。16 is a flowchart for explaining the operation of the control device of the eighth embodiment.
 1 実施形態1
 本実施形態の制御システム10は、図1に示すように、制御装置20、中継装置30および通信装置41,42を備える。
 制御システム10では、Ethernet(登録商標)規格のケーブル、またIEEE802.11規格の無線等の通信メディア11から13により、制御装置20と中継装置とが、中継装置30と通信装置41,42とが、それぞれ接続されている。
 制御装置20は、中継装置30と通信、および中継装置30を介して通信装置41,42とマルチキャストで通信する装置である。以下において、マルチキャストで送信されるデータをマルチキャストデータという。
 中継装置30は、例えばIGMP Snoopingに対応したルータである。
 IGMP(インターネット管理プロトコル)は、インターネットエンジニアリングタスクフォース(IETF)で規定され、IPネットワーク上でマルチキャストでの通信を行うために、マルチキャストグループへの参加、離脱を管理するプロトコルである。IGMPは、異なるネットワークから送信されたマルチキャストデータを自身が管理するネットワークに転送するか否かを判断する。
 IGMP Snoopingとは、IGMPを応用した機能であり、制御装置20が送信した依頼情報(IGMP Report)を盗聴して、通信ポート毎にマルチキャストデータの転送可否を判断するOSI参照モデルにおけるレイヤ2の機能である。ここで、依頼情報とは、制御装置20が中継装置30に対して特定のマルチキャストアドレスグループのデータ(マルチキャストデータ)の転送を要求する情報であり、制御装置20が受信したいマルチキャストアドレスを含んでいる。IGMP Snoopingを有する中継装置30は、通信ポートごとにマルチキャストによる転送の許否を判断している。この機能を搭載した中継装置30は、依頼情報を受信すると、受信してから予め定められた期間が終了するまでの間は当該依頼情報を受信した通信ポートに対してマルチキャストによる転送を許可する。これにより、中継装置30は、通信ポートごとに、マルチキャストの転送期間を管理することができる。
 中継装置30は、IGMP Snoopingを用いて、制御装置20が送信した依頼情報を盗聴し、依頼情報から制御装置20が転送を要求するマルチキャストアドレスを識別し、管理する。
 中継装置30は、制御装置20が転送を要求するマルチキャストアドレスグループのデータ(マルチキャストデータ)を受信した場合、制御装置20と接続された通信ポート33にマルチキャストデータを転送し、他の通信ポートは転送しないように制御する。
 また、中継装置30はマルチキャストデータの転送を要求する通信ポートごとに、マルチキャストデータの転送を許可する期間(マルチキャスト転送期間)を管理する。例えば、制御装置20の依頼情報を受信してからマルチキャスト転送期間の時間長を超過して、通信装置41から依頼情報と一致したマルチキャストアドレスグループ宛のマルチキャストデータを中継装置30が受信する。この場合、中継装置30は、該データを制御装置20と接続された通信ポートには転送しない。ここで、マルチキャスト転送期間の時間長は、例えば5分である。
 通信装置41,42は、マルチキャストデータを扱う装置であり、例えばエアコン、照明器具、パーソナルコンピュータ、タブレット端末等であり、プロセッサやメモリを有している。通信装置41,42の機能は、メモリに記憶されているプログラムをプロセッサが実行することにより実現される。
 以下、制御装置20および中継装置30の構成について説明する。ただし、以下に説明する構成は、本発明の一例に過ぎず、本発明は、下記実施形態に限定されることはなく、この実施形態以外であっても、本発明に係る技術的思想を逸脱しない範囲であれば、設計等に応じて種々の変更が可能である。
 (1)制御装置20
 制御装置20は、図1に示すように、第1通信部21(通信部)と通信処理部22とを備える。制御装置20は、プロセッサやメモリを有しており、通信処理部22の機能は、メモリに記憶されているプログラムをプロセッサが実行することにより実現される。また、制御装置20が有するプロセッサは、通信装置41,42が有するプロセッサよりも性能が高いプロセッサである。
 第1通信部21は、通信メディア11を介して、中継装置30と通信を行う。また、第1通信部21は、通信メディア11および中継装置30を介して、通信装置41,42と通信を行う。
 第1通信部21は、後述する通信処理部22の制御により、依頼情報を定期的に送信する。
 また、第1通信部21は、通信装置41,42に対して、状態の設定変更を要求するための要求情報(Set要求)を、中継装置30を介して送信する。要求情報を送信後、第1通信部21は、要求情報を受信したことを表す応答情報(Set応答)を通信装置41,42から受信する。さらに、第1通信部21は、設定変更後の状態を表すマルチキャストデータを通信装置41,42から受信する。これにより、制御装置20は、通信装置41,42の制御が可能となる。
 通信処理部22は、制御装置20の全体動作を制御する。通信処理部22は、依頼情報を定期的に第1通信部21に送信させる。また、通信処理部22は、第1通信部21に要求情報を送信させ、応答情報およびマルチキャストデータを受信させる。
 (2)中継装置30
 中継装置30は、図1に示すように、第2通信部31(通信経路)と制御部32とを備える。中継装置30は、プロセッサやメモリを有しており、制御部32の機能は、メモリに記憶されているプログラムをプロセッサが実行することにより実現される。
 第2通信部31は、複数の通信ポート(通信経路)を備えている。なお、本実施形態では、中継装置30は、3つの通信ポート33から35を備えている。
 通信ポート33は、制御装置20の第1通信部21と通信メディア11を介して接続されている。また、通信ポート34は、通信装置41と通信メディア12を介して接続されて、通信ポート35は、通信装置42と通信メディア13を介して接続されている。
 通信ポート33から35は、接続先の装置から送信されたデータ(例えば依頼情報およびマルチキャストデータ)を受信すると、受信したデータを制御部32へ出力する。
 制御部32は、中継装置30の全体動作を制御する。
 制御部32は、中継装置30が管理する通信ポートごとにマルチキャストデータの転送可否を判断する第1管理テーブルを有している。第1管理テーブルでは、制御装置20及び通信装置41、通信装置42からの依頼情報から、通信ポート、転送するマルチキャストグループアドレス、及び有効期限等が対応づけられている。有効期限とは、マルチキャスト転送期間が終了する時刻である。制御部32は、有効期限までに、その有効期限に対応付けられたネットワークアドレスから再度依頼情報を受け取らない場合には、第1管理テーブルから削除する。
 制御部32は、制御装置20および通信装置41,42からマルチキャストデータを受信した場合、受信したマルチキャストデータのマルチキャストグループアドレスと一致するマルチキャストグループアドレスが第1管理テーブルに存在するか確認する。第1管理テーブルに存在すると判断した場合、制御部32は、受信したマルチキャストデータを、該マルチキャストデータのマルチキャストグループアドレスに該当する通信ポートに転送する。
 制御部32は、制御装置20から要求情報を受信した場合、受信した要求情報の宛先である通信装置が接続された通信ポートに転送する。
 (3)通信装置41,42
 通信装置41,42は、同じ機能を有しているので、ここでは、通信装置41について説明する。
 通信装置41は、制御装置20から中継装置30を介して、要求情報を受信すると、応答情報を、中継装置30を介して制御装置20へ送信する。そして、通信装置41は、受信した要求情報の内容に基づいて、状態の設定の変更を行う。例えば、通信装置41がエアコンである場合には、要求情報の内容が「設定温度を1度下げる」という要求であれば、通信装置は、設定温度を1度下げる。通信装置41は、設定変更後の状態を表すマルチキャストデータを送信する。
 また、通信装置41は、付属のリモコン等の操作で状態の設定変更がされると、設定変更後の状態を表すマルチキャストデータを送信する。
 1.2 動作
 (1)動作概要
 ここでは、制御システム10の全体の動作概要、特に依頼情報を送信する動作について、図2に示すシーケンス図を用いて説明する。
 制御装置20は、起動時に依頼情報を送信する(ステップS5)。
 制御装置20は、ステップS5で依頼情報を送信した後、定期的(例えば3分ごと)に、依頼情報を送信する(ステップS10~ステップS20)。ここでは、依頼情報の送信周期を3分としているが、送信周期は、マルチキャスト転送期間の時間長以下であればよい。
 中継装置30は、通信装置41から送信されたマルチキャストデータを受信すると、マルチキャストデータを要求する制御装置20へ送信する(ステップS25,S30)。
 制御装置20は、マルチキャストデータの受信後も、定期的に(例えば3分ごと)に、依頼情報を送信する(ステップS35)。
 これにより、制御装置20は、中継装置30のマルチキャスト転送期間内に前記依頼情報を送信する事で、通信装置41、42から送信されるマルチキャストデータを中継装置30を介して受信することができる。
 (2)制御装置20の動作
 ここでは、制御装置20の動作、特に依頼情報を送信する動作について、図3に示す流れ図を用いて説明する。
 制御装置20の通信処理部22は、起動時に第1通信部21に依頼情報を送信させる(ステップS100)。
 通信処理部22は、所定時間(例えば3分)が経過したか否かを判断する(ステップS105)。
 所定時間が経過したと判断する場合(ステップS105における「Yes」)、通信処理部22は、依頼情報を第1通信部21に送信させる(ステップS110)。依頼情報が送信された後、処理はステップS105へ戻る。
 所定時間が経過していないと判断する場合(ステップS105における「No」)、処理は、所定時間の経過待ちとなる。
 本実施形態では、制御装置20は、3分ごとに依頼情報を送信している。また、中継装置30で管理するマルチキャスト転送期間の時間長は5分である。そのため、制御装置20は、マルチキャスト転送期間内に必ず依頼情報を送信している。つまり、中継装置30の通信ポート管理テーブルでは、制御装置20と接続される通信ポートでのマルチキャスト転送期間の有効期限が常に更新されるので、マルチキャストによる通信可能な期間が途切れることはない。
 このため、制御装置20は、中継装置がマルチキャストデータの転送期間を管理する中継装置であっても、マルチキャストデータを受信することができる。また、通常、他の装置(通信装置41,42)の制御は、該他の装置よりも処理性能が高い装置(制御装置20)が行う。そこで、制御装置20が、依頼情報の送信を定期的に行っても、他の装置が行う場合と比較して、その処理負荷は低い。つまり、システム全体として、マルチキャストデータの送受信に対する確実性および信頼性は向上する。
 2 実施形態2
 実施形態1では、中継装置30は、IGMP Snoopingに対応した中継装置であったが、中継装置30は、IGMPに対応した中継装置であり、かつ自装置とは異なるIPネットワークを管理する中継装置50と接続されている点が異なる。
 以下、本実施形態では、実施形態1と異なる点を中心に説明する。なお、実施形態1と同様の構成要素には同一の符号を付して説明を適宜省略する。
 図4に示す本実施形態の制御システム10は、制御装置20、中継装置30、50および通信装置41、42を備える。中継装置30と中継装置50は異なるIPネットワークを管理するルータであり、IGMPに対応したルータである。通信ポート33,34,35は、中継装置30が管理するIPネットワークと通信するための通信ポートである。通信ポート36(通信経路)は異なるIPネットワークと通信するための通信ポートである。中継装置50は、通信メディア14により通信ポート36と接続されている。
 第1通信部21は、中継装置30から問合せ情報を受信すると、受信した問合せ情報を通信処理部22へ出力し、通信処理部22の制御により依頼情報を中継装置30へ送信する。問合せ情報とは、マルチキャストデータの受信を希望するか否かを問い合わせる情報であり、例えばIGMP Queryである。
 通信処理部22は、第1通信部21を介して中継装置30から問合せ情報を受け取ると、その応答として依頼情報を第1通信部21に送信させ、その後の依頼情報の定期的な送信を停止するように、第1通信部21を制御する。
 中継装置30は、上述したように、例えばIGMPに対応したルータである。中継装置30は、中継装置30が管理するIPネットワークにマルチキャストデータの受信を希望する装置が存在するか確認するためのクエリである問合せ情報(IGMPQuery)を定期的(例えば5分)に送信する。特定グループ宛のマルチキャストデータの受信を希望する装置は、問合せ情報を受信すると、受信を希望するマルチキャストアドレスを中継装置30に通知する。これにより、中継装置30は、マルチキャストで送信されたデータを受信すると、マルチキャストデータの転送を要求するネットワークに、受信したマルチキャストデータを送信する。
 また、中継装置30は、マルチキャストデータの転送を要求するネットワークごとに、マルチキャスト転送期間を管理している。マルチキャスト転送期間内に、管理対象のネットワークから依頼情報が受信されない場合には、マルチキャスト転送期間の経過後はマルチキャストで送信されたデータはそのネットワークに転送されない。
 制御部32は、中継装置30が管理するネットワークごとにマルチキャストデータの転送可否を判断する第2管理テーブルを有している。第2管理テーブルでは、制御装置20及び通信装置41、通信装置42からの依頼情報から、転送先のネットワークアドレス、転送するマルチキャストグループアドレス、及び有効期限等が対応づけられている。有効期限とは、マルチキャスト転送期間が終了する時刻である。制御部32は、定期的に問い合わせ情報を送信し、第2通信部31から依頼情報を受け取ると、第2管理テーブルに、転送先のネットワークアドレス、転送するマルチキャストグループアドレス、及び有効期限等を登録する。
 制御部32は、有効期限までに、その有効期限に対応付けられたネットワークアドレスから再度依頼情報を受け取らない場合には、第2管理テーブルから削除する。
 制御部32は、制御装置20および通信装置41,42からマルチキャストデータを受信した場合、送信されたマルチキャストデータのマルチキャストグループアドレスが、第2管理テーブルで管理されているアドレスであるか確認する。制御部32は、該当するマルチキャストアドレスグループであると判断した場合、受信したマルチキャストデータを該当するネットワークに転送する。
 中継装置50は、中継装置30が管理するIPネットワークと異なるIPネットワークを管理する点が中継装置30と異なるだけであり、その構成は、中継装置30と同様であるので、ここでの説明は省略する。
 制御システム10の全体の動作概要、特に依頼情報を送信する動作について、図5に示すシーケンス図を用いて説明する。
 制御装置20は、起動時に依頼情報を送信する(ステップS200)。
 制御装置20は、ステップS200で依頼情報を送信した後、定期的(例えば1分ごと)に、依頼情報を送信する(ステップS205~ステップS215)。
 中継装置30は、制御装置20および通信装置41,42へ問合せ情報を送信する(ステップS220からステップS230)。
 制御装置20および通信装置41,42のそれぞれは、問合せ情報に対する応答として、依頼情報を送信する(ステップS235~ステップS245)。
 制御装置20および通信装置41,42のそれぞれは、問合せ情報に対する応答として、依頼情報を送信した後は、定期的に送信される問合せ情報に応答することで、マルチキャスト通信が可能となる。
 本実施形態では、制御装置20は、問合せ情報を受信するまでは1分ごとに依頼情報を送信している。また、中継装置30で管理するマルチキャスト転送期間の時間長は5分である。そのため、制御装置20は、マルチキャスト転送期間内に必ず依頼情報を送信している。つまり、中継装置30の通信ポート管理テーブルでは、制御装置20と接続される通信ポートでのマルチキャスト転送期間の有効期限が常に更新されるので、問合せ情報による管理が開始されるまでは、マルチキャストによる通信の期間が途切れることはない。
 また、本実施形態では、中継装置の問い合わせ情報を受信した後、制御装置20は依頼情報の定期的な送信を止めるため、無駄なトラフィックを抑制することができる。
 次に、制御装置20の動作、特に依頼情報を送信する動作について、図6に示す流れ図を用いて説明する。
 制御装置20の通信処理部22は、起動時に第1通信部21に依頼情報を送信させる(ステップS300)。
 通信処理部22は、所定時間(例えば1分)が経過したか否かを判断する(ステップS305)。
 所定時間を経過したと判断する場合(ステップS305における「Yes」)、通信処理部22は、依頼情報を第1通信部21に送信させる(ステップS310)。依頼情報が送信された後、処理はステップS305へ戻る。
 所定時間が経過していないと判断する場合(ステップS305における「No」)、通信処理部22は、第1通信部21が問合せ情報を中継装置30から受信したか否かを判断する(ステップS315)。
 問合せ情報を受信していないと判断する場合(ステップS315における「No」)、処理はステップS305へ戻る。
 問合せ情報を受信したと判断する場合(ステップS315における「Yes」)、通信処理部22は、問合せ情報に対する応答として、依頼情報を第1通信部21に送信させ(ステップS320)、処理を終了する。
 以上説明したように、制御装置20では、問合せ情報を受信し、その応答として依頼情報を送信した後は、処理は終了している。これにより、ステップS305およびステップS310で行われる第1通信部21による定期的(1分ごと)に依頼情報を送信することを停止させていることが分かる。
 本実施形態では、制御装置20は、問合せ情報を受信するまでは1分ごとに依頼情報を送信している。また、中継装置30で管理するマルチキャスト転送期間は5分である。そのため、制御装置20は、マルチキャスト転送期間内に必ず依頼情報を送信している。つまり、中継装置30の通信ポート管理テーブルでは、制御装置20と接続される通信ポートでのマルチキャスト転送期間の有効期限が常に更新されるので、問合せ情報による管理が開始されるまでは、マルチキャストによる通信の期間が途切れることはない。
 3 実施形態3
 実施形態1では、中継装置30が具備する通信ポート毎に1台ずつ装置を接続していたが、本実施形態では、中継装置30の1つの通信ポートに複数の装置が接続される点が異なる。例えば、無線の通信ポートに複数の装置が接続された場合、及びEthernet(登録商標)等の通信ポートにスイッチングハブ等を接続し、複数の装置が接続する場合等である。
 以下、本実施形態では、実施形態1と異なる点を中心に説明する。なお、実施形態1と同様の構成要素には同一の符号を付して説明を適宜省略する。
 本実施形態の制御システム10は、図7に示すように、制御装置20、中継装置30および通信装置41~44を備える。
 制御装置20と中継装置30とは無線で通信を行う。また、制御装置20と通信装置41,42とは、中継装置30を介して無線で通信を行う。なお、制御装置20と中継装置30との間の無線通信、および制御装置20と通信装置41,42との間の中継装置30を介した無線通信では、第1の周波数帯域が使用される。
 また、中継装置30と、通信装置43,44とは、無線で通信を行う。なお、中継装置30と通信装置43,44との間の無線通信では、第1の周波数帯域とは異なる第2の周波数帯域が使用される。
 図7に示す本実施形態の制御装置20の第1通信部21は、中継装置30との間で第1の周波数帯域を使用して無線通信を行う。また、第1通信部21は、中継装置30を介して、通信装置41,42との間で第1の周波数帯域を使用して無線通信を行う。
 具体的には、本実施形態の第1通信部21は、通信処理部22の制御により、依頼情報を定期的(3分ごと)に無線で送信する。
 中継装置30は、実施形態1と同様に、IGMP Snoopingに対応した中継装置である。
 中継装置30は、実施形態1と同様に、マルチキャストデータを要求する装置に対するマルチキャスト転送期間(例えば、5分)を管理している。マルチキャスト転送期間内に、管理対象の装置から送信された依頼情報が盗聴(受信)されない場合には、マルチキャストで送信されたデータはその装置が接続された通信ポートには転送されない。
 本実施形態の中継装置30の第2通信部31は、図7に示すように、第1送受信部37(通信経路)と第2送受信部38(通信経路)とを備えている。
 第1送受信部37は、第1の周波数帯域を使用して、アンテナ37aを介して、制御装置20および通信装置41,42と無線通信を行う。具体的には、第1送受信部37は、IGMP Snoopingを用いて、第1の周波数帯域を使用して無線で送信された依頼情報を盗聴(受信)すると、盗聴(受信)した依頼情報を制御部32へ出力する。第1送受信部37は、制御装置20からマルチキャストで送信されたマルチキャストデータ(第1データ)を受信すると、受信した第1データを制御部32へ出力する。第1送受信部37は、通信装置41,42からマルチキャストで送信されたマルチキャストデータ(第2データ)を受信すると、受信した第2データを制御部32へ出力する。
 第2送受信部38は、第2の周波数帯域を使用して、アンテナ38aを介して、通信装置43,44と無線通信を行う。具体的には、第2送受信部38は、IGMP Snoopingを用いて、第2の周波数帯域を使用して無線で送信された依頼情報を盗聴(受信)すると、盗聴(受信)した依頼情報を制御部32へ出力する。第2送受信部38は、通信装置43,44からマルチキャストで送信されたマルチキャストデータ(第3データ)を受信すると、受信した第3データを制御部32へ出力する。
 なお、以降の説明において、第1送受信部37と第2送受信部38とを区別する必要がない場合には、送受信部39と記述する。
 本実施形態の制御部32は、中継装置30の全体動作を制御する。
 制御部32は、無線に使用する周波数帯域ごとにマルチキャストの転送可否を判断する周波数帯域管理テーブルを有している。周波数帯域管理テーブルでは、第1送受信部37および第2送受信部38のうちマルチキャストの転送が可能な周波数帯域を識別する帯域識別子と、有効期限とが対応付けられている。有効期限とは、マルチキャスト転送期間が終了する時刻である。
 制御部32は、依頼情報を受け取ると、受け取った時刻にマルチキャスト転送期間である時間(例えば5分)を加算し、有効期限を算出する。さらに、制御部32は、第2通信部31から依頼情報を受け取ると、受け取った依頼情報の出力元が第1送受信部37および第2送受信部38のいずれであるかを特定する。制御部32は、特定した送受信部39(第1送受信部37または第2送受信部38)が使用する周波数帯域を識別する帯域識別子が周波数帯域管理テーブルに登録されているか否かを判断する。登録されていなければ、特定した送受信部39が使用する周波数帯域の帯域識別子と、有効期限とを対応付けて周波数帯域管理テーブルに登録する。登録されていれば、その帯域識別子に対応付けられている有効期限を、算出された有効期限に更新する。
 制御部32は、有効期限までに、その有効期限に対応付けられた送受信部39から再度依頼情報を受け取らない場合には、その帯域識別子および有効期限を、周波数帯域管理テーブルから削除する。
 制御部32は、第1送受信部37がマルチキャストデータ(第1データおよび第2データのいずれかのデータ)を受信すると、周波数帯域管理テーブルを用いて、マルチキャストデータの転送が可能な1つ以上の送受信部39を特定する。また、制御部32は、第2送受信部38がマルチキャストデータ(第3データ)を受信すると、周波数帯域管理テーブルを用いて、マルチキャストデータの転送が可能な1つ以上の送受信部39を特定する。制御部32は、特定した1つ以上の送受信部39にマルチキャストデータを送信させる。また、制御部32は、第1~第3データのいずれでもないデータを受信、つまりマルチキャスト転送の管理外のマルチキャストアドレスグループのデータを受信すると、該データの転送は行わない。
 本実施形態の制御部32は、上述したように、無線通信に使用される周波数帯域ごとに、マルチキャスト通信の可否を判断している。つまり、周波数帯域を、実施形態1で説明したケーブルと接続される通信ポートと同様の概念と捉えることができる。
 本実施形態の制御システム10の全体の動作概要、特に依頼情報を送信する動作は、実施形態1と比較して、中継装置30が具備する1つの通信ポートに対して複数の装置が接続された点が異なるのみであり、処理内容としては、変更がない。そのため、本実施形態の制御システム10の全体の動作概要についての説明は、省略する。
 また、本実施形態の制御装置20の動作、特に依頼情報を送信する動作についても、中継装置30が具備する1つの通信ポートに対して複数の装置が接続された点が実施形態1と異なるのみであり、処理内容としては、変更がない。そのため、本実施形態の制御装置20の動作についての説明も省略する。
 以上説明したように、本実施形態の制御システム10では、無線で通信を行っている。そして、中継装置30は、無線通信に使用される周波数帯域ごとに、マルチキャスト通信の可否を判断している。そのため、中継装置30は、一の周波数帯域を使用する制御装置(例えば制御装置20)から依頼情報を受信すると、一の周波数帯域を使用する他の装置(ここでは、通信装置41,42)に対してもマルチキャストの通信を可能とする。つまり、制御装置20と通信装置41,42との間で双方向のマルチキャスト通信が可能となる。
 4 実施形態4
 実施形態1では、中継装置30が管理するマルチキャスト転送期間は一律に5分であるとしたが、本実施形態では、中継装置30の機種(製造元)ごとにマルチキャスト転送期間が異なっている点が異なる。
 以下、本実施形態では、実施形態1と異なる点を中心に説明する。なお、実施形態1と同様の構成要素には同一の符号を付して説明を適宜省略する。
 本実施形態の制御装置20は、中継装置30のMACアドレスを用いて、中継装置30が管理するマルチキャスト転送期間の情報を取得し、取得したマルチキャスト転送期間の情報に基づいて、依頼情報を送信する送信周期を決定する。
 本実施形態の制御装置20は、図8に示すように、さらに記憶部23を有している。
 記憶部23は、中継装置の製造元と、該中継装置で管理するマルチキャスト転送期間とを対応付けた転送期間管理テーブルを記憶している。また、MACアドレスは、16進数を使って12桁で表される。そして、12桁のうち前半の6桁は、製造元を表している。そこで、記憶部23は、製造元と、MACアドレスの前半6桁とを対応付けた製造元管理テーブルも記憶している。
 第1通信部21は、通信処理部22の制御により、MACアドレスを要求するアドレス要求を中継装置30に送信し、その後、中継装置30からMACアドレスを受信する。
 通信処理部22は、第1通信部21がアドレス要求を送信し、MACアドレスを受信するように、第1通信部21を制御する。通信処理部22は、第1通信部21がMACアドレスを受信すると、該MACアドレス、製造元管理テーブルおよび転送期間管理テーブルを用いて、中継装置30が管理するマルチキャスト転送期間を特定する。通信処理部22は、特定したマルチキャスト転送期間の時間長を、またはその時間長よりも短い時間長を送信周期として、依頼情報を送信するように第1通信部21を制御する。
 本実施形態の制御システム10の全体の動作概要、特に依頼情報の送信周期を決定する動作について、図9に示すシーケンス図を用いて説明する。
 制御装置20の第1通信部21は、例えば管理プロトコルを含むデータを中継装置30から受信する(ステップS400)。
 制御装置20の通信処理部22は、受信したデータに含まれるMACアドレスから中継装置30の製造元を特定する(ステップS405)。具体的には、通信処理部22は、記憶部23で記憶された製造元管理テーブルから、受信したデータに含まれるMACアドレスの前半6桁の数値と一致する数値を検索する。一致する数値が存在する場合には、その数値に対応付けられた製造元の情報を取得する。
 通信処理部22は、特定した製造元から中継装置30が管理するマルチキャスト転送期間を特定する(ステップS410)。具体的には、通信処理部22は、記憶部23で記憶された転送期間管理テーブルから、特定した製造元と一致する製造元を検索する。一致する製造元が存在する場合には、その製造元に対応付けられたマルチキャスト転送期間を特定する。
 通信処理部22は、特定したマルチキャスト転送期間の時間長を、またはその時間長よりも短い時間長を依頼情報の送信周期として決定する(ステップS415)。
 第1通信部21は、決定された送信周期で依頼情報を送信する(ステップS420,S425)。
 次に、制御装置20の動作、特に依頼情報の送信周期を決定して、依頼情報を送信する動作について、図10に示す流れ図を用いて説明する。
 制御装置20の通信処理部22は、第1通信部21が受信したデータに含まれるMACアドレスを取得する(ステップS500)。
 通信処理部22は、取得したMACアドレスと製造元管理テーブルとを用いて、中継装置30の製造元を特定する(ステップS505)。
 通信処理部22は、特定した製造元と転送期間管理テーブルとを用いて、中継装置30が管理するマルチキャスト転送期間を特定する(ステップS510)。
 通信処理部22は、特定したマルチキャスト転送期間の時間長と同一の時間長を、またはその時間長よりも短い時間長を送信周期として決定する(ステップS515)。
 通信処理部22は、第1通信部21に依頼情報を送信させる(ステップS520)。
 通信処理部22は、決定した送信周期が経過したか否かを判断する(ステップS525)。
 経過したと判断する場合(ステップS525における「Yes」)、通信処理部22は、依頼情報を第1通信部21に送信させる(ステップS530)。依頼情報が送信された後、処理はステップS525へ戻る。
 送信周期が経過していないと判断する場合(ステップS525における「No」)、通信処理部22は、処理は、送信周期の経過待ちとなる。
 これにより、制御装置20は、中継装置30の製造元ごとにマルチキャスト転送期間が異なる場合であっても、マルチキャストによる通信が可能な期間が途切れることがないように、依頼情報を定期的に送信することができる。
 本実施形態では、マルチキャスト転送期間と中継装置30の製造元とを対応付けて記憶したが、これに限定されない。マルチキャスト転送期間と中継装置30の型番を対応付けて記憶してもよい。つまり、制御装置20は、マルチキャスト転送期間と、中継装置30を識別する情報とを対応付けて記憶していればよい。
 なお、記憶部23は、制御装置20が備えるとしたが、これに限定されない。例えば、記憶部23は、ネットワークを介して制御装置20と接続されてもよい。
 また、実施形態2~実施形態4の構成は、互いに組み合わせても適用可能である。
 5 実施形態5
 実施形態1では、依頼情報を送信する送信周期は固定(例えば3分)としたが、本実施形態では、依頼情報の送信周期を動的に短縮できる点が異なる。
 以下、本実施形態では、実施形態1と異なる点を中心に説明する。なお、実施形態1と同様の構成要素には同一の符号を付して説明を適宜省略する。
 以下、中継装置30が管理するマルチキャストの転送の許否の情報を管理情報という。
 通信処理部22は、予め定められた送信周期で依頼情報を送信する。通信処理部22は、中継装置30を介して通信装置41,42とデータの送受信を行うことで、送信周期の短縮の必要の有無を決定する。ここで、送受信されるデータは、例えば、ECHONET LiteのGet要求、Get応答、INF要求およびINF応答である。
 送信周期の短縮が必要であると判断する場合には、通信処理部22は、現在決定している送信周期を、より短い送信周期に決定する。
 次に、本実施形態の制御システム10の全体の動作概要、特に依頼情報の送信周期の短縮する動作について、図11に示すシーケンス図を用いて説明する。
 制御装置20は、依頼情報を中継装置30に送信する(ステップS600)。
 制御装置20は、ステップS600で依頼情報が送信されてから所定時間T0(T01)が経過すると、マルチキャスト転送検出処理を行う(ステップS605)。具体的には、制御装置20は、ユニキャストで送信されるデータ(ユニキャストデータ)を要求するGet要求(Get_Request)を中継装置30を介して通信装置41へ送信する(ステップS610,S615)。制御装置20は、通信装置41が送信したGet応答(Get_Response)を中継装置30を介して受信する(ステップS620,S625)。制御装置20は、マルチキャストデータを要求するINF要求(INF_Request)を中継装置30を介して通信装置41へ送信する(ステップS630,S6
 35)。制御装置20は、通信装置41が送信したINF応答(INF)を中継装置30を介して受信する(ステップS640,S645)。ここで、GET要求、GET応答およびINF要求は、ユニキャストデータであり、INF応答は、マルチキャストデータである。ここで、Get要求がユニキャストデータ要求情報に相当し、INF要求がマルチキャストデータ要求情報に相当する。また、所定時間T0は、送信周期T1から、マルチキャスト転送検出処理の処理時間長ΔTを減算した時間である。
 制御装置20は、INF応答を受信後、ステップS600で依頼情報を送信してから所定時間T1(T11)が経過したと判断する場合に、依頼情報を中継装置30に送信する(ステップS650)。
 ここで、中継装置30は、自装置が管理するマルチキャスト転送期間の時間長(転送許可時間)が短縮されたとする(ステップS655)。短縮後の転送許可時間T2は、送信周期T1より短い時間とする。中継装置30は、短縮後の転送許可時間T2で依頼情報を受信しない場合には、管理情報を破棄する(ステップS660)。
 ステップS650で依頼情報を送信してから所定時間T0(T02)が経過すると、制御装置20は、マルチキャスト転送検出処理を行う(ステップS665)。具体的には、上述したように、制御装置20は、Get要求の送信、Get応答の受信、およびINF要求の送信を行う(ステップS670~ステップS695)。中継装置30が管理情報を破棄しているので、マルチキャストデータの転送は行われない。そのため、ステップS700で通信装置41が送信したINF応答を受信することができない。
 制御装置20は、ステップS665で行われたマルチキャスト転送検出処理でINF応答を受信しないので、依頼情報の送信周期を短縮し(ステップS705)、依頼情報を中継装置30に送信する(ステップS710)。制御装置20は、ステップS710で依頼情報を送信してから所定時間T4が経過すると、マルチキャスト転送検出処理を行う(ステップS715)。ここで、所定時間T4は、短縮後の送信周期T3からΔTを減算した時間である。
 制御装置20は、マルチキャスト転送検出処理の結果に応じた送信周期で、依頼情報を中継装置30に送信する(ステップS720)。
 なお、図11において、送信周期T11と送信周期T12は、説明の都合上、これらの周期は異なっているように描かれているが、実際には同一の周期である。また、所定時間T01とT02、転送許可時間T21とT22、図面上、異なっているように描かれているが、実際には同一の時間長である。また、図11に記載されている各ΔTも同様に、説明の都合上、これらの時間長も異なっているように描かれているが、実際には同一の時間長である。
 次に、本実施形態の制御装置20の動作、特に依頼情報の送信周期を短縮する動作について、図12に示す流れ図を用いて説明する。
 制御装置20の通信処理部22は、起動時に第1通信部21に依頼情報を送信させる(ステップS750)。
 通信処理部22は、所定時間が経過したか否かを判断する(ステップS755)。ここで、所定時間とは、上述したように、依頼情報の送信周期からマルチキャスト転送検出処理の処理時間長△Tを減算した時間である。
 依頼情報を送信してから所定時間が経過したと判断する場合(ステップS755における「Yes」)、通信処理部22は、マルチキャスト転送検出処理を行う(ステップS760)。具体的には、通信処理部22は、Get要求を送信し、その応答としてユニキャストデータ(Get応答)を受信したか否かを判断する(ステップS765)。
 ユニキャストデータを受信したと判断する場合(ステップS765における「Yes」)、通信処理部22は、INF要求を送信し、その応答としてマルチキャストデータ(INF応答)を受信したか否かを判断する(ステップS770)。
 マルチキャストデータを受信していないと判断する場合(ステップS770における「No」)、通信処理部22は、依頼情報の送信周期を短縮する(ステップS775)。マルチキャストデータが受信されない場合には、現時点でマルチキャスト転送期間の時間長(転送許可時間)が経過し、中継装置30において管理情報が破棄されていることが考えられる。そこで、制御装置20は、管理情報が破棄されていることを防止するため、依頼情報の送信周期を短縮する。
 ユニキャストデータを受信していないと判断する場合(ステップS765における「No」)、通信処理部22は、処理を終了する。
 マルチキャストデータを受信したと判断する場合(ステップS770における「Yes」)、通信処理部22は、先の依頼情報を送信してから送信周期が経過したと判断すると依頼情報を第1通信部21に送信させる(ステップS780)。依頼情報が送信された後、処理はステップS755へ戻る。
 また、依頼情報の送信周期を短縮した後、通信処理部22は、依頼情報を第1通信部21に送信させる(ステップS780)。依頼情報が送信された後、処理はステップS755へ戻る。この場合、通信処理部22は、短縮した送信周期で依頼情報の送信を行うよう第1通信部21を制御する。
 所定時間が経過していないと判断する場合(ステップS755における「No」)、処理は、所定時間の経過待ちとなる。
 これにより、制御装置20は、中継装置30のマルチキャスト転送期間の時間長が短縮された場合であっても、マルチキャストによる通信が可能な期間が途切れることがないように、依頼情報を定期的に送信することができる。
 また、ユーザが中継装置30のマルチキャスト転送期間を知らない場合でも、制御装置20は、マルチキャスト転送検出処理を繰り返すことで、管理情報が破棄されるとこがない最適な送信周期で依頼情報を送信することができる。つまり、制御装置20は、中継装置30のマルチキャスト転送期間の時間長(転送許可時間)と同一の時間長、または転送許可時間よりも短い時間長を送信周期として依頼情報を送信することができる。
 ここで、通信処理部22が、第1通信部21に依頼情報を送信させる機能、およびマルチキャスト転送検出処理を行う機能の組み合わせが、応答検出処理に相当する。
 通常、中継装置30によるマルチキャストデータの転送の制御に関わらず、ユニキャストデータの送受信は行われる。そのため、もし、ユニキャストデータの送受信ができない場合には、例えば中継装置30の通信ポートの物理的な不具合が考えられる。そのため、本実施形態では、ユニキャストデータを受信しない場合には、処理を終了している。なお、この場合、制御装置20は、中継装置30に不具合が生じているエラーメッセージをユーザに通知してもよい。
 なお、本実施形態では、依頼情報の送信周期ごとに、マルチキャスト転送検出処理を行っているが、これに限定されない。
 マルチキャスト転送検出処理により、制御装置20でマルチキャストデータ(INF応答)が受信されると、以降のマルチキャスト転送検出処理を、依頼情報の送信の度に行う必要はない。マルチキャスト転送検出処理により、制御装置20でマルチキャストデータ(INF応答)が受信されると、その後のマルチキャスト転送検出処理は、1日後、1週間後、または1か月後といった単位で行ってもよい。マルチキャスト転送検出処理により、制御装置20でマルチキャストデータが受信されない場合には、制御装置20は、依頼情報の送信周期を短縮して、マルチキャストデータが受信されるまで依頼情報を送信する度にマルチキャスト転送検出処理を繰り返す。そして、マルチキャストデータが受信されると、制御装置20は、以降のマルチキャスト転送検出処理を、依頼情報の送信の度には行わず、1日後、1週間後、または1か月後といった単位で行う。
 本実施形態では、マルチキャスト転送検出処理は、通信装置41のみを用いて行っているが、通信装置が複数台存在する場合には、各通信装置に対してマルチキャスト転送検出処理を行うとしてもよい。
 なお、本実施形態では、Get要求(ユニキャストデータ要求情報)はユニキャストで送信されるデータであるとしたが、これに限定されない。
 Get要求は、ブロードキャストで送信されてもよい。
 Get要求がブロードキャストで送信される場合には、Get要求が全ての通信装置41,42に受信されるという保証がないという短所がある。また複数の通信装置41,42から一斉にGet応答が返信されるため、制御装置20が全てのGet応答を受信しきれない虞があるという短所もある。しかし、単発の送信で複数の通信装置41,42宛にGet要求を届けられるという長所がある。
 Get要求がユニキャストで送信される場合には、長所および短所がブロードキャストによる送信とは逆になる。すなわち、ユニキャストで送信されたGet要求は通信装置41,42のそれぞれに確実に送信されるが、送信先の通信装置の数のユニキャスト通信を行う必要がある。
 または、制御装置20は、Get要求を送信する通信装置の台数に応じて、ユニキャストによる送信およびブロードキャストによる送信を切り替えてもよい。この場合、制御装置20は、通信対象となる通信装置の台数を記憶している。通信処理部22は、記憶している通信装置の台数が閾値未満であれば、ユニキャストによる送信を選択し、記憶している通信装置の台数が閾値以上であれば、ブロードキャストによる送信を選択する。または、通信処理部22は、ユーザ操作によって、ユニキャストによる送信またはブロードキャストによる送信を選択してもよい。
 また、通信処理部22は、ブロードキャストによる送信を選択した場合には、Get要求の送信を複数回繰り返して第1通信部21に行わせてもよい。例えば、制御装置20と通信装置41,42とが、中継装置30を介して無線で通信を行っている場合、電波状況によっては、Get応答が受信できない通信装置や、Get応答が中継装置30に到達しない通信装置が存在する可能性がある。そこで、通信処理部22は、第1通信部21にGet要求をブロードキャストで複数回送信させることで、ブロードキャストで送信されたGet要求に対するGet応答の確認の精度を向上させることができる。
 また、通信処理部22は、第1通信部21にINF要求(マルチキャストデータ要求情報)をマルチキャストで複数回繰り返し送信させてもよい。これにより、マルチキャストで送信されたINF要求に対するINF応答の確認の精度を向上させることができる。
 また、実施形態2~実施形態5の構成は、互いに組み合わせても適用可能である。
 6 実施形態6
 実施形態5では、依頼情報を定期的に送信する通常の処理内に、マルチキャストデータ転送検出処理を含めて、依頼情報の送信周期を決定している。本実施形態では、通常の処理とは別に依頼情報の送信周期を決定する処理を行う点が実施形態5と異なる。
 以下、本実施形態では、実施形態5と異なる点を中心に説明する。なお、実施形態5と同様の構成要素には同一の符号を付して説明を適宜省略する。
 通信処理部22は、起動時に依頼情報を第1通信部21に送信させ、依頼情報の送信から所定時間が経過すると、上述したマルチキャスト転送検出処理を行う。ここで、所定時間とは、例えば現時点で設定されている送信周期である。通信処理部22は、マルチキャスト転送検出処理において、マルチキャストデータ(INF応答)が受信されない場合には、所定時間を短縮する。通信処理部22は、マルチキャストデータ(INF応答)が受信されるまでの間、上述した依頼情報の送信、マルチキャスト転送検出処理を行う。
 通信処理部22は、マルチキャストデータが受信されると、その時点で設定されている所定時間を送信周期とする。通信処理部22は、決定した送信周期で依頼情報を送信するように、第1通信部21を制御する。
 また、通信処理部22は、通信装置41,42からのマルチデータの受信の可否を定期的に判断する処理(判断処理)を行っており、該判断処理でマルチデータの受信ができないと判断すると、起動時と同様に、送信周期を決定する。
 次に、本実施形態の制御システム10の全体の動作概要、特に依頼情報の送信周期を短縮する動作について、図13に示すシーケンス図を用いて説明する。
 制御装置20は、起動時に依頼情報を中継装置30に送信する(ステップS800)。
 制御装置20は、ステップS600で依頼情報が送信されてから所定時間T5が経過すると、マルチキャスト転送検出処理を行う(ステップS805)。具体的には、制御装置20は、ユニキャストデータを要求するGet要求(Get_Request)を中継装置30を介して通信装置41へ送信するよう第1通信部を制御する(ステップS810,S815)。制御装置20は、通信装置41が送信したGet応答(Get_Response)を中継装置30を介して受信するよう第1通信部21を制御する(ステップS820,S825)。制御装置20は、マルチキャストデータを要求するINF要求(INF_Request)を中継装置30を介して通信装置41へ送信するよう第1通信部21を制御する(ステップS830,S835)。ここで、Get要求がユニキャストデータ要求情報に相当し、INF要求がマルチキャストデータ要求情報に相当する。
 ここでは、制御装置20は、通信装置41からのINF応答(INF)を受信できないとする(ステップS840)。
 制御装置20は、通信装置41からのINF応答を受信できない場合には、所定時間T5を短縮する(ステップS845)。なお、短縮後の所定時間をT6と記述する。マルチキャストデータが受信されない場合には、現時点でマルチキャスト転送期間の時間長(転送許可時間)が経過し、中継装置30において管理情報が破棄されていることが考えられる。そこで、制御装置20は、管理情報が破棄されていることを防止するため、依頼情報の送信周期を短縮する。
 制御装置20は、依頼情報を中継装置30に送信する(ステップS850)。
 ステップS600で依頼情報を送信してから所定時間T6が経過すると、制御装置20は、マルチキャスト転送検出処理を行う(ステップS855)。具体的には、上述したように、制御装置20は、Get要求の送信、Get応答の受信、およびINF要求の送信を行うように第1通信部を制御する(ステップS860~ステップS890)。
 ここでは、所定時間の短縮により、制御装置20は、通信装置41からのINF応答を受信する(ステップS890,S895)。
 次に、本実施形態の制御装置20の動作、特に送信周期を短縮する動作について、図14に示す流れ図を用いて説明する。
 制御装置20の通信処理部22は、起動時に第1通信部21に依頼情報を送信させる(ステップS900)。
 通信処理部22は、所定時間(T5)が経過したか否かを判断する(ステップS905)。
 依頼情報を送信してから所定時間が経過したと判断する場合(ステップS905における「Yes」)、通信処理部22は、マルチキャスト転送検出処理を行う(ステップS910)。具体的には、通信処理部22は、Get要求を第1通信部21に送信させ、その応答としてユニキャストデータ(Get応答)を第1通信部21が受信したか否かを判断する(ステップS915)。
 ユニキャストデータが受信されたと判断する場合(ステップS915における「Yes」)、通信処理部22は、INF要求を第1通信部21に送信させ、その応答としてマルチキャストデータ(INF応答)を受信したか否かを判断する(ステップS920)。
 マルチキャストデータを受信したと判断する場合(ステップS920における「Yes」)、通信処理部22は、現時点で設定されている所定時間を送信周期として決定する(ステップS925)。通信処理部22は、決定された送信周期で依頼情報を送信するように第1通信部21を制御する。
 マルチキャストデータが受信されていないと判断する場合(ステップS920における「No」)、通信処理部22は、所定時間を短縮し(ステップS930)、依頼情報を第1通信部21に送信させる(ステップS935)。依頼情報が送信された後、処理はステップS905へ戻る。この場合、ステップS905での判定処理は、短縮された所定時間を用いて行われる。
 所定時間が経過していないと判断する場合(ステップS905における「No」)、処理は、所定時間の経過待ちとなる。
 図13,14では、制御装置20は、起動時に送信周期の決定を行っている。しかしながら、上述した判断処理によりマルチキャストデータが受信できないことを検出した場合も、制御装置20は、同様の処理の流れで送信周期を決定することができる。
 これにより、制御装置20は、マルチキャストによる通信可能な期間が途切れることがないように、依頼情報を送信周期を決定することができる。
 本実施形態においても、実施形態5と同様に、ユニキャストデータの送受信ができない場合には、制御装置20は、中継装置30に不具合が生じているエラーメッセージをユーザに通知してもよい。
 また、本実施形態においても、実施形態5と同様に、Get要求は、ブロードキャストで送信されてもよい。
 7 実施形態7
 本実施形態では、実施形態5と実施形態6とを組み合わせた制御システム10について説明する。
 まず、本実施形態の制御システム10に新規に中継装置30が設置される、または既存の中継装置を新規の中継装置30に置き換える場合について説明する。
 この場合、制御装置20は、新規の中継装置30について何ら情報を取得していないため、中継装置30で設定されているマルチキャスト転送期間の情報も取得していない。そのため、制御装置20は、制御装置20は、依頼情報の定期的な送信を行う前に、依頼情報の送信周期が新規の中継装置30のマルチキャスト転送期間の時間長以下となるように送信周期を決定する必要がある。
 そこで、本実施形態では、制御装置20は、依頼情報の定期的な送信を行う前に、実施形態6で説明した依頼情報の送信周期を決定する処理(決定処理)を行う。
 具体的には、制御装置20の通信処理部22は、まず図14のステップS900で示されるように依頼情報を第1通信部21に送信させる。通信処理部22は、制御装置20で予め記憶されている所定時間が経過すると、マルチキャスト転送検出処理を行う(図14のステップS910参照)。
 通信処理部22は、マルチキャスト転送検出処理でマルチキャストデータ(INF要求)が受信されない場合には、所定時間を短縮し、再度依頼情報を第1通信部21に送信させる(図14のステップS930,S935参照)。
 通信処理部22は、マルチキャスト転送検出処理でマルチキャストデータが受信された場合には、その時点で設定されている所定時間を送信周期として決定する。
 これにより、制御装置20は、新規の中継装置30で設定されたマルチキャスト転送期間の情報を取得していない場合であっても、中継装置30のマルチキャスト転送期間の時間長以下となるように送信周期を決定することができる。
 次に本実施形態において、制御装置20が、上述した決定処理で決定された送信周期で依頼情報を送信する場合について説明する。
 本実施形態では、通信処理部22は、決定処理で送信周期が決定されると、図12で示す処理に基づいて、依頼情報を定期的に第1通信部21に送信させる。
 具体的には、通信処理部22は、まず図12のステップS750で示されるように依頼情報を第1通信部21に送信させる。依頼情報の送信後、通信処理部22は、所定時間が経過すると、マルチキャスト転送検出処理を行う。ここでの所定時間は、実施形態5で説明したように、送信周期(例えばT1)からマルチキャスト転送検出処理の処理時間長(例えばΔT)を減算した時間である。
 マルチキャスト転送検出処理でマルチキャストデータ(INF要求)が受信されない場合には、送信周期を短縮し、再度依頼情報を第1通信部21に送信させる(図12のステップS775,S780参照)。
 通信処理部22は、マルチキャスト転送検出処理でマルチキャストデータが受信された場合には、その時点で設定されている送信周期で、以降の依頼情報の送信を第1通信部21に行わせる。
 これにより、制御装置20は、決定処理で送信周期が決定された後でも、送信周期を短縮することができる。
 また、実施形態5で説明したように、本実施形態においても、依頼情報の送信周期ごとに、マルチキャスト転送検出処理を行う必要はない。例えば、実施形態5で説明したように、マルチキャスト転送検出処理により、制御装置20でマルチキャストデータ(INF応答)が受信されると、その後のマルチキャスト転送検出処理は、1日後、1週間後、または1か月後といった単位で行ってもよい。マルチキャスト転送検出処理により、制御装置20でマルチキャストデータが受信されない場合には、制御装置20は、依頼情報の送信周期を短縮して、マルチキャストデータが受信されるまで依頼情報を送信する度にマルチキャスト転送検出処理繰り返す。そして、マルチキャストデータが受信されると、制御装置20は、以降のマルチキャスト転送検出処理を、依頼情報の送信の度には行わず、1日後、1週間後、または1か月後といった単位で行う。
 また、本実施形態においても、実施形態5,6と同様に、Get要求は、ブロードキャストで送信されてもよい。
 8 実施形態8
 実施形態1では、制御装置20は、依頼情報を定期的に送信するとしたが、本実施形態で、依頼情報の他、依頼情報を中継装置30へ送信するように要求するために問合せ情報も定期的に送信する点が異なる。問合せ情報とは、上述したように、例えばIGMPQueryである。
 以下、本実施形態では、実施形態1と異なる点を中心に説明する。なお、実施形態1と同様の構成要素には同一の符号を付して説明を適宜省略する。
 本実施形態の第1通信部21は、通信処理部22の制御により、中継装置30を介して通信装置41、42に問合せ情報を送信する。問合せ情報の送信のタイミングは、依頼情報を中継装置30へ送信するタイミングと同一であってもよいし、異なるタイミングであってもよい。
 通信処理部22は、問合せ情報(IGMP Query)をマルチキャストで送信するように、第1通信部21を制御する。ここで、IGMPQueryについては、マルチキャストデータの転送が許可されていない通信ポートに対してもマルチキャストの転送が中継装置において行われるようにIGMPの規格で規定されている。そのため、本実施形態では、中継装置30は、問合せ情報(IGMP Query)を送信すると、受信した問合せ情報を通信装置41,42が接続された通信ポート34,35に転送される。これにより、通信装置41,42は、問合せ情報を受信することができる。
 通信装置41,42は、問合せ情報を受信すると、特定グループ宛のマルチキャストデータの受信を希望する場合には、受信を希望するマルチキャストアドレスを含む依頼情報(IGMP Report)を制御装置20に中継装置30を介して通知する。
 中継装置30の制御部32は、問合せ情報を受信すると、通信装置41,42へ送信する。制御部32は、IGMP Snoopingにより依頼情報に含まれるマルチキャストアドレスを取得すると、依頼情報を受信した通信ポートに対してマルチキャスト転送期間が経過するまでの間、マルチキャストデータの転送を許可する。
 次に、本実施形態の制御システム10の全体の動作概要、特に依頼情報および問合せ情報を送信する動作について、図15に示すシーケンス図を用いて説明する。
 制御装置20は、起動時に問合せ情報を、中継装置30を介して通信装置41,42に送信する(ステップS1000~ステップS1010)。
 問合せ情報を受信した通信装置41,42は、特定グループ宛のマルチキャストデータの受信を希望する場合には、問合せ情報の応答として依頼情報を中継装置30に送信する(ステップS1015,S1020)。
 制御装置20は、問合せ情報を送信した後、依頼情報を中継装置30に送信する(ステップS1025)。
 送信周期T1(T15)が終了すると、次の送信周期T1(T16)において、制御装置20は、問合せ情報を、中継装置30を介して通信装置41,42に送信する(ステップS1030~ステップS1040)。
 問合せ情報を受信した通信装置41,42は、特定グループ宛のマルチキャストデータの受信を希望する場合には、依頼情報を中継装置30に送信する(ステップS1045,S1050)。
 制御装置20は、問合せ情報を送信した後、依頼情報を中継装置30に送信する(ステップS1055)。
 送信周期T1(T16)が終了すると、次の送信周期T1(T17)において、制御装置20は、問合せ情報を、中継装置30を介して通信装置41,42に送信する(ステップS1060~ステップS1070)。
 問合せ情報を受信した通信装置41,42は、特定グループ宛のマルチキャストデータの受信を希望する場合には、依頼情報を中継装置30に送信する(ステップS1075,S1080)。
 制御装置20は、問合せ情報を送信した後、依頼情報を中継装置30に送信する(ステップS1085)。
 次に、本実施形態の制御装置20の動作、特に依頼情報および問合せ情報を送信する動作について、図16に示す流れ図を用いて説明する。
 制御装置20の通信処理部22は、起動時に第1通信部21に問合せ情報および依頼情報を送信させる(ステップS1100,S1105)。
 通信処理部22は、所定時間が経過したか否かを判断する(ステップS1110)。ここでの所定時間は、依頼情報の送信周期である。
 所定時間を経過したと判断する場合(ステップS1110における「Yes」)、通信処理部22は、第1通信部21に問合せ情報および依頼情報を送信させる(ステップS1115,S1120)。問合せ情報および依頼情報が送信された後、処理はステップS1110へ戻る。
 所定時間が経過していないと判断する場合(ステップS1110における「No」)、処理は、所定時間の経過待ちとなる。
 以上説明したように、制御装置20は、問合せ情報を定期的に送信することで、中継装置30において異なる通信ポートに接続された通信装置41,42に、依頼情報を送信させる。そのため、中継装置30は、制御装置20だけでなく通信装置41,42、にもマルチキャストデータを転送させることができる。
 なお、制御装置20は、問合せ情報をマルチキャストデータとして送信したが、通信装置41,42のアドレスの情報を取得している場合には、ユニキャストデータとして送信してもよい。または、制御装置20は、問合せ情報をブロードキャストにより送信してもよい。
 9 その他の変形例
 以上、実施形態1~6に基づいて本発明について説明したが、本発明は上述した実施形態に限られない。例えば、以下のような変形例が考えられる。
 (1)上記各実施形態において、制御装置20のみが依頼情報を送信するとしたが、これに限定されない。通信装置41,42も定期的に依頼情報を送信してもよい。
 (2)上記実施形態1において、通信ポート33から35のそれぞれは、1台の装置(制御装置20、通信装置41,42)と接続されたが、これに限定されない。
 通信ポート33から35のうち少なくとも1つは、他の中継装置と接続されてもよい。この場合、中継装置30は、マルチキャストデータを他の中継装置の配下に接続された1つ以上の装置に送信することができる。
 (3)上記実施形態1において、通信ポートの数が3つとしたが、これに限定されない。通信ポートの数は、2以上であればよい。
 また、実施形態2において、無線通信に使用する周波数帯域は、第1の周波数帯域および第2の周波数帯域の2つとしたが、これに限定されない。無線通信に使用する周波数帯域は、1つ以上であればよい。
 この場合、第2通信部31は、例えば無線通信に使用する周波数帯域の数に応じた送受信部を備える。
 (4)上記実施形態2において、制御装置20は、依頼情報の定期的な送信を起動時に開始したが、これに限定されない。
 制御装置20の通信処理部22は、問合せ情報を受信した後、所定時間内(例えば5分内)に次の問合せ情報を受信しない場合に、依頼情報の定期的な送信を開始してもよい。
 (5)上記実施形態1において、中継装置30は、問合せ情報(IGMP Query)を定期的に出力してもよい。
 この場合、制御装置20は、中継装置30から問合せ情報を受信するまでは、実施形態1と同様に、定期的(例えば3分ごと)に依頼情報を中継装置30に送信している。制御装置20は、問合せ情報を受信すると、依頼情報を中継装置30に送信し、その後依頼情報を定期的に送信することを停止する。
 (6)上記実施形態および変形例を組み合わせてもよい。
 10 まとめ
 以上説明したように、制御装置20は、中継装置30を介して、制御対象である1つ以上の通信装置41,42と通信し、1つ以上の通信装置41,42の制御を行う。中継装置30は、マルチキャストで送信されたデータの転送を依頼する依頼情報を受信してからマルチキャスト転送期間が終了するまでの間は当該依頼情報を受信した通信経路に対してデータの転送を許可する。ここで、通信経路は、例えば通信ポート33~35、第1送受信部37および第2送受信部38である。制御装置20は、中継装置30との通信、および中継装置30を介した1つ以上の通信装置41,42との通信を行う第1通信部21(通信部)と、通信処理部22とを備える。通信処理部22は、依頼情報をマルチキャスト転送期間内に第1通信部21に送信させる。
 この構成によると、制御装置20は、マルチキャスト転送期間内に依頼情報を送信している。通常、他の装置(通信装置41,42)よりも処理性能が高い装置(制御装置20)が、当該他の装置を制御する。そこで、制御装置20が、マルチキャスト転送期間内に依頼情報を送信することを定期的に行っても、他の装置が行う場合と比較して、その処理負荷は低い。つまり、制御装置20は、システム全体の信頼性の低下を防ぎつつ、マルチキャストの通信ができる。
 ここで、制御装置20は、中継装置30を識別する識別情報と、マルチキャスト転送期間とを対応付けて記憶する記憶部を備えることが好ましい。第1通信部21は、中継装置30を識別する識別情報(MACアドレスの前半6桁の数値)を受信する。通信処理部22は、第1通信部21が受信した識別情報に対応するマルチキャスト転送期間を特定し、依頼情報を特定したマルチキャスト転送期間内に第1通信部21に送信させる。
 この構成によると、制御装置20は、中継装置30ごとにマルチキャスト転送期間が異なる場合であっても、マルチキャストによる通信の期間が途切れることがないように、依頼情報を定期的に送信することができる。
 ここで、通信処理部22は、応答検出処理を行う。応答検出処理は、依頼情報を第1通信部21に送信させて、所定時間が経過すると、1つ以上の通信装置41,42のうち少なくとも1つの通信装置に、マルチキャストデータの送信を要求するマルチキャストデータ要求情報を第1通信部に送信させる処理である。通信処理部22は、第1通信部21がマルチキャストデータを受信しない場合には、所定時間を短縮して、応答検出処理を行う。通信処理部22は、マルチキャストデータを受信した場合には、その時点で設定されている所定時間に応じた送信周期で、依頼情報を送信するように第1通信部21を制御する。
 この構成によると、制御装置20は、依頼情報の送信周期を動的に短縮するので、中継装置30のマルチキャスト転送期間に応じて、マルチキャストによる通信の期間が途切れることがないように依頼情報を定期的に送信することができる。
 ここで、通信処理部22は、応答検出処理において、1つ以上の通信装置41,42のうち少なくとも1つの通信装置に、ユニキャストデータの送信を要求するユニキャストデータ要求情報を第1通信部21に送信させる。通信処理部22は、第1通信部21が、ユニキャストデータを受信し、かつマルチキャストデータを受信しない場合には、所定時間を短縮する。
 この構成によると、制御装置20は、中継装置30が通信経路に対してマルチキャストで送信されたデータの転送を制御している場合にのみ、送信周期を短縮することができる。なぜなら、通常、制御装置20が、ユニキャストデータおよびマルチキャストデータの双方とも受信できない場合には、中継装置30自体の不具合が考えられるからである。
 ここで、通信処理部22は、さらに、依頼情報を中継装置30へ送信するように要求する問合せ情報を、1つ以上の通信装置41,42へマルチキャスト転送期間内に第1通信部21に送信させることが好ましい。
 この構成によると、制御装置20は、自装置だけでなく、マルチキャストデータの転送を要求する他の装置(通信装置41,42)に対してもマルチキャストデータの転送を可能とすることができる。
 ここで、第1通信部21は、中継装置30との通信、および中継装置30を介した1つ以上の通信装置41,42との通信を、周波数帯域を用いた無線通信で行うことが好ましい。中継装置30は、周波数帯域を用いた無線経路を通信経路としてマルチキャストで送信されたデータの転送を制御する。
 この構成によると、制御装置20は、依頼情報を中継装置30に無線通信で送信することができる。そのため、中継装置30は、制御装置20が無線通信で使用する周波数帯域と同一の周波数帯域を使用する通信装置41,42に対してもマルチキャストデータの転送を可能とする。つまり、制御装置20と通信装置41,42との間で双方向のマルチキャストの通信が可能となる。
 また本願のプログラムは、コンピュータを、上記いずれかの制御装置20として機能させるためのプログラムである。
 このプログラムによると、システム全体の信頼性の低下を防ぎつつ、マルチキャストの通信ができる。
1 Embodiment 1
As shown in FIG. 1, the control system 10 of the present embodiment includes a control device 20, a relay device 30, and communication devices 41 and 42.
In the control system 10, the control device 20 and the relay device, the relay device 30, and the communication devices 41 and 42 are connected by an Ethernet (registered trademark) standard cable or IEEE 802.11 standard wireless communication media 11 to 13. , Each connected.
The control device 20 is a device that communicates with the relay device 30 and communicates with the communication devices 41 and 42 via the relay device 30 by multicast. Hereinafter, data transmitted by multicast is referred to as multicast data.
The relay device 30 is a router that supports, for example, IGMP Snooping.
IGMP (Internet Management Protocol) is a protocol that is defined by the Internet Engineering Task Force (IETF) and manages participation and departure from a multicast group in order to perform multicast communication on an IP network. IGMP determines whether or not multicast data transmitted from a different network is transferred to a network managed by the IGMP.
IGMP Snooping is a function that applies IGMP, and is a layer 2 function in the OSI reference model that eavesdrops on request information (IGMP Report) transmitted by the control device 20 and determines whether multicast data can be transferred for each communication port. It is. Here, the request information is information that the control device 20 requests the relay device 30 to transfer data of a specific multicast address group (multicast data), and includes the multicast address that the control device 20 wants to receive. . The relay device 30 having IGMP Snooping determines whether or not transfer by multicast is permitted for each communication port. When the relay device 30 equipped with this function receives the request information, the relay device 30 permits the communication port that has received the request information to transfer by multicast until the predetermined period ends after receiving the request information. Thereby, the relay apparatus 30 can manage the multicast transfer period for each communication port.
The relay device 30 eavesdrops on the request information transmitted by the control device 20 by using IGMP Snooping, and identifies and manages the multicast address for which the control device 20 requests transfer from the request information.
When the control device 20 receives the data (multicast data) of the multicast address group that the control device 20 requests to transfer, the relay device 30 transfers the multicast data to the communication port 33 connected to the control device 20, and the other communication ports transfer the data. Control not to.
In addition, the relay device 30 manages a period during which multicast data transfer is permitted (multicast transfer period) for each communication port that requests multicast data transfer. For example, the relay device 30 receives the multicast data addressed to the multicast address group that matches the request information from the communication device 41 after the request information of the control device 20 is received and the time length of the multicast transfer period is exceeded. In this case, the relay device 30 does not transfer the data to the communication port connected to the control device 20. Here, the time length of the multicast transfer period is, for example, 5 minutes.
The communication devices 41 and 42 are devices that handle multicast data, such as an air conditioner, a lighting fixture, a personal computer, a tablet terminal, and the like, and have a processor and a memory. The functions of the communication devices 41 and 42 are realized by the processor executing a program stored in the memory.
Hereinafter, configurations of the control device 20 and the relay device 30 will be described. However, the configuration described below is only an example of the present invention, and the present invention is not limited to the following embodiment, and the technical idea according to the present invention is not deviated from this embodiment. Various changes can be made in accordance with the design or the like as long as they are not.
(1) Control device 20
As shown in FIG. 1, the control device 20 includes a first communication unit 21 (communication unit) and a communication processing unit 22. The control device 20 includes a processor and a memory, and the function of the communication processing unit 22 is realized by the processor executing a program stored in the memory. Moreover, the processor which the control apparatus 20 has is a processor whose performance is higher than the processor which the communication apparatuses 41 and 42 have.
The first communication unit 21 communicates with the relay device 30 via the communication medium 11. The first communication unit 21 communicates with the communication devices 41 and 42 via the communication medium 11 and the relay device 30.
The first communication unit 21 periodically transmits request information under the control of the communication processing unit 22 described later.
In addition, the first communication unit 21 transmits request information (Set request) for requesting the state setting change to the communication devices 41 and 42 via the relay device 30. After transmitting the request information, the first communication unit 21 receives response information (Set response) indicating that the request information has been received from the communication devices 41 and 42. Further, the first communication unit 21 receives multicast data representing the state after the setting change from the communication devices 41 and 42. Thereby, the control device 20 can control the communication devices 41 and 42.
The communication processing unit 22 controls the overall operation of the control device 20. The communication processing unit 22 causes the first communication unit 21 to periodically transmit the request information. In addition, the communication processing unit 22 causes the first communication unit 21 to transmit request information and receive response information and multicast data.
(2) Relay device 30
As shown in FIG. 1, the relay device 30 includes a second communication unit 31 (communication path) and a control unit 32. The relay device 30 includes a processor and a memory, and the function of the control unit 32 is realized by the processor executing a program stored in the memory.
The second communication unit 31 includes a plurality of communication ports (communication paths). In the present embodiment, the relay device 30 includes three communication ports 33 to 35.
The communication port 33 is connected to the first communication unit 21 of the control device 20 via the communication medium 11. The communication port 34 is connected to the communication device 41 via the communication medium 12, and the communication port 35 is connected to the communication device 42 via the communication medium 13.
Upon receiving data (for example, request information and multicast data) transmitted from the connection destination device, the communication ports 33 to 35 output the received data to the control unit 32.
The control unit 32 controls the overall operation of the relay device 30.
The control unit 32 has a first management table that determines whether multicast data can be transferred for each communication port managed by the relay device 30. In the first management table, a communication port, a multicast group address to be transferred, an expiration date, and the like are associated with each other from request information from the control device 20, the communication device 41, and the communication device. The expiration date is the time when the multicast transfer period ends. When the request information is not received again from the network address associated with the expiration date by the expiration date, the control unit 32 deletes the request information from the first management table.
When receiving the multicast data from the control device 20 and the communication devices 41 and 42, the control unit 32 checks whether a multicast group address that matches the multicast group address of the received multicast data exists in the first management table. When determining that it exists in the first management table, the control unit 32 transfers the received multicast data to the communication port corresponding to the multicast group address of the multicast data.
When the request information is received from the control device 20, the control unit 32 transfers the request information to the communication port to which the communication device that is the destination of the received request information is connected.
(3) Communication devices 41 and 42
Since the communication devices 41 and 42 have the same function, the communication device 41 will be described here.
When the communication device 41 receives request information from the control device 20 via the relay device 30, the communication device 41 transmits response information to the control device 20 via the relay device 30. And the communication apparatus 41 changes the setting of a state based on the content of the received request information. For example, when the communication device 41 is an air conditioner, if the content of the request information is a request “decrease the set temperature once”, the communication device lowers the set temperature once. The communication device 41 transmits multicast data indicating the state after the setting change.
In addition, when the setting of the state is changed by an operation of the attached remote controller or the like, the communication device 41 transmits multicast data indicating the state after the setting change.
1.2 Operation
(1) Operation overview
Here, an outline of the overall operation of the control system 10, particularly, an operation for transmitting request information will be described with reference to the sequence diagram shown in FIG.
The control apparatus 20 transmits request information at the time of starting (step S5).
After transmitting the request information in step S5, the control device 20 transmits the request information periodically (for example, every 3 minutes) (steps S10 to S20). Here, the transmission period of the request information is 3 minutes, but the transmission period may be equal to or less than the time length of the multicast transfer period.
When receiving the multicast data transmitted from the communication device 41, the relay device 30 transmits the multicast data to the control device 20 that requests the multicast data (steps S25 and S30).
The control device 20 transmits the request information periodically (for example, every 3 minutes) even after receiving the multicast data (step S35).
Accordingly, the control device 20 can receive the multicast data transmitted from the communication devices 41 and 42 via the relay device 30 by transmitting the request information within the multicast transfer period of the relay device 30.
(2) Operation of the control device 20
Here, the operation of the control device 20, particularly the operation of transmitting request information, will be described with reference to the flowchart shown in FIG.
The communication processing unit 22 of the control device 20 causes the first communication unit 21 to transmit request information at the time of activation (step S100).
The communication processing unit 22 determines whether a predetermined time (for example, 3 minutes) has elapsed (step S105).
When determining that the predetermined time has elapsed (“Yes” in step S105), the communication processing unit 22 transmits the request information to the first communication unit 21 (step S110). After the request information is transmitted, the process returns to step S105.
If it is determined that the predetermined time has not elapsed (“No” in step S105), the process waits for the elapse of the predetermined time.
In the present embodiment, the control device 20 transmits request information every 3 minutes. The time length of the multicast transfer period managed by the relay device 30 is 5 minutes. For this reason, the control device 20 always transmits the request information within the multicast transfer period. That is, in the communication port management table of the relay device 30, the validity period of the multicast transfer period in the communication port connected to the control device 20 is constantly updated, so that the multicast communication period is not interrupted.
Therefore, the control device 20 can receive multicast data even if the relay device is a relay device that manages the transfer period of multicast data. Further, normally, control of other devices (communication devices 41 and 42) is performed by a device (control device 20) having higher processing performance than the other devices. Therefore, even if the control device 20 periodically transmits the request information, the processing load is low as compared with the case where the other device performs. That is, the reliability and reliability of multicast data transmission / reception is improved as a whole system.
2 Embodiment 2
In the first embodiment, the relay device 30 is a relay device compatible with IGMP Snooping. However, the relay device 30 is a relay device compatible with IGMP and manages a different IP network from the own device. And the connection point is different.
In the following, the present embodiment will be described focusing on differences from the first embodiment. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.
The control system 10 of this embodiment shown in FIG. 4 includes a control device 20, relay devices 30 and 50, and communication devices 41 and 42. The relay device 30 and the relay device 50 are routers that manage different IP networks, and are routers that support IGMP. The communication ports 33, 34, and 35 are communication ports for communicating with the IP network managed by the relay device 30. The communication port 36 (communication path) is a communication port for communicating with different IP networks. The relay device 50 is connected to the communication port 36 by the communication medium 14.
When receiving the inquiry information from the relay device 30, the first communication unit 21 outputs the received inquiry information to the communication processing unit 22, and transmits the request information to the relay device 30 under the control of the communication processing unit 22. The inquiry information is information for inquiring whether or not to receive multicast data, and is, for example, IGMP Query.
When the communication processing unit 22 receives the inquiry information from the relay device 30 via the first communication unit 21, the communication processing unit 22 transmits the request information to the first communication unit 21 as a response, and stops the subsequent periodic transmission of the request information. Thus, the first communication unit 21 is controlled.
As described above, the relay device 30 is, for example, a router that supports IGMP. The relay device 30 periodically transmits inquiry information (IGMPQuery), which is a query for confirming whether there is a device that desires to receive multicast data in the IP network managed by the relay device 30 (for example, 5 minutes). Upon receiving the inquiry information, a device that desires to receive multicast data addressed to a specific group notifies the relay device 30 of the multicast address that it desires to receive. Thus, when the relay device 30 receives the data transmitted by multicast, the relay device 30 transmits the received multicast data to the network that requests transfer of the multicast data.
The relay device 30 manages the multicast transfer period for each network that requests the transfer of multicast data. If the request information is not received from the management target network within the multicast transfer period, the data transmitted by multicast is not transferred to the network after the multicast transfer period elapses.
The control unit 32 has a second management table for determining whether or not multicast data can be transferred for each network managed by the relay device 30. In the second management table, from the request information from the control device 20, the communication device 41, and the communication device 42, the network address of the transfer destination, the multicast group address to be transferred, the expiration date, and the like are associated. The expiration date is the time when the multicast transfer period ends. When the control unit 32 periodically transmits inquiry information and receives the request information from the second communication unit 31, the transfer destination network address, the multicast group address to be transferred, the expiration date, etc. are registered in the second management table. To do.
When the request information is not received again from the network address associated with the expiration date before the expiration date, the control unit 32 deletes the request information from the second management table.
When the control unit 32 receives multicast data from the control device 20 and the communication devices 41 and 42, the control unit 32 checks whether the multicast group address of the transmitted multicast data is an address managed in the second management table. If the control unit 32 determines that the corresponding multicast address group, the control unit 32 transfers the received multicast data to the corresponding network.
The relay device 50 is different from the relay device 30 only in that it manages an IP network different from the IP network managed by the relay device 30, and the configuration thereof is the same as that of the relay device 30. To do.
An overview of the overall operation of the control system 10, particularly an operation for transmitting request information, will be described with reference to the sequence diagram shown in FIG.
The control apparatus 20 transmits request information at the time of starting (step S200).
After transmitting the request information in step S200, the control device 20 transmits the request information periodically (for example, every minute) (steps S205 to S215).
The relay device 30 transmits inquiry information to the control device 20 and the communication devices 41 and 42 (from step S220 to step S230).
Each of the control device 20 and the communication devices 41 and 42 transmits request information as a response to the inquiry information (steps S235 to S245).
Each of the control device 20 and the communication devices 41 and 42 transmits the request information as a response to the inquiry information, and then responds to the inquiry information periodically transmitted, thereby enabling multicast communication.
In the present embodiment, the control device 20 transmits request information every minute until the inquiry information is received. The time length of the multicast transfer period managed by the relay device 30 is 5 minutes. For this reason, the control device 20 always transmits the request information within the multicast transfer period. That is, in the communication port management table of the relay device 30, the expiration date of the multicast transfer period at the communication port connected to the control device 20 is constantly updated. Therefore, until the management by the inquiry information is started, the multicast communication is performed. The period is never interrupted.
Moreover, in this embodiment, after receiving the inquiry information of a relay apparatus, since the control apparatus 20 stops transmitting request information regularly, it can suppress useless traffic.
Next, the operation of the control device 20, particularly the operation of transmitting request information, will be described with reference to the flowchart shown in FIG.
The communication processing unit 22 of the control device 20 causes the first communication unit 21 to transmit request information at the time of activation (step S300).
The communication processing unit 22 determines whether or not a predetermined time (for example, 1 minute) has elapsed (step S305).
When determining that the predetermined time has elapsed (“Yes” in step S305), the communication processing unit 22 causes the first communication unit 21 to transmit request information (step S310). After the request information is transmitted, the process returns to step S305.
When determining that the predetermined time has not elapsed (“No” in step S305), the communication processing unit 22 determines whether the first communication unit 21 has received the inquiry information from the relay device 30 (step S315). ).
If it is determined that the inquiry information has not been received (“No” in step S315), the process returns to step S305.
When determining that the inquiry information has been received (“Yes” in step S315), the communication processing unit 22 transmits the request information to the first communication unit 21 as a response to the inquiry information (step S320), and ends the process. .
As described above, in the control device 20, after receiving the inquiry information and transmitting the request information as a response, the processing is completed. Thereby, it turns out that transmission of request information by the 1st communication part 21 performed by Step S305 and Step S310 is stopped regularly (every minute).
In the present embodiment, the control device 20 transmits request information every minute until the inquiry information is received. The multicast transfer period managed by the relay device 30 is 5 minutes. For this reason, the control device 20 always transmits the request information within the multicast transfer period. That is, in the communication port management table of the relay device 30, the expiration date of the multicast transfer period at the communication port connected to the control device 20 is constantly updated. Therefore, until the management by the inquiry information is started, the multicast communication is performed. The period is never interrupted.
3 Embodiment 3
In the first embodiment, one device is connected to each communication port included in the relay device 30, but in the present embodiment, a plurality of devices are connected to one communication port of the relay device 30. . For example, there are a case where a plurality of devices are connected to a wireless communication port, a case where a switching hub is connected to a communication port such as Ethernet (registered trademark), and a case where a plurality of devices are connected.
In the following, the present embodiment will be described focusing on differences from the first embodiment. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.
As shown in FIG. 7, the control system 10 of the present embodiment includes a control device 20, a relay device 30, and communication devices 41 to 44.
The control device 20 and the relay device 30 communicate wirelessly. Further, the control device 20 and the communication devices 41 and 42 communicate wirelessly via the relay device 30. Note that the first frequency band is used in wireless communication between the control device 20 and the relay device 30 and in wireless communication via the relay device 30 between the control device 20 and the communication devices 41 and 42.
In addition, the relay device 30 and the communication devices 43 and 44 communicate wirelessly. In the wireless communication between the relay device 30 and the communication devices 43 and 44, a second frequency band different from the first frequency band is used.
The first communication unit 21 of the control device 20 of the present embodiment illustrated in FIG. 7 performs wireless communication with the relay device 30 using the first frequency band. In addition, the first communication unit 21 performs wireless communication with the communication devices 41 and 42 via the relay device 30 using the first frequency band.
Specifically, the first communication unit 21 according to the present embodiment wirelessly transmits the request information periodically (every 3 minutes) under the control of the communication processing unit 22.
Similar to the first embodiment, the relay device 30 is a relay device that supports IGMP Snooping.
As in the first embodiment, the relay device 30 manages a multicast transfer period (for example, 5 minutes) for a device that requests multicast data. If the request information transmitted from the managed device is not wiretapped (received) within the multicast transfer period, the data transmitted by multicast is not transferred to the communication port to which the device is connected.
As illustrated in FIG. 7, the second communication unit 31 of the relay device 30 according to the present embodiment includes a first transmission / reception unit 37 (communication path) and a second transmission / reception unit 38 (communication path).
The 1st transmission / reception part 37 performs radio | wireless communication with the control apparatus 20 and the communication apparatuses 41 and 42 via the antenna 37a using a 1st frequency band. Specifically, the first transmission / reception unit 37 controls the request information that has been wiretapped (received) when wiretapping (receiving) the request information transmitted wirelessly using the first frequency band by using IGMP Snooping. To the unit 32. When the first transmission / reception unit 37 receives multicast data (first data) transmitted from the control device 20 by multicast, the first transmission / reception unit 37 outputs the received first data to the control unit 32. When the first transmission / reception unit 37 receives multicast data (second data) transmitted by multicast from the communication devices 41 and 42, the first transmission / reception unit 37 outputs the received second data to the control unit 32.
The second transmission / reception unit 38 performs wireless communication with the communication devices 43 and 44 via the antenna 38a using the second frequency band. Specifically, the second transmission / reception unit 38 controls the request information that has been wiretapped (received) when wiretapping (receiving) the request information transmitted wirelessly using the second frequency band using IGMP Snooping. To the unit 32. When receiving the multicast data (third data) transmitted from the communication devices 43 and 44 by multicast from the communication devices 43 and 44, the second transmission / reception unit 38 outputs the received third data to the control unit 32.
In the following description, when there is no need to distinguish between the first transmission / reception unit 37 and the second transmission / reception unit 38, the transmission / reception unit 39 is described.
The control unit 32 of this embodiment controls the overall operation of the relay device 30.
The control unit 32 has a frequency band management table for determining whether or not multicast transfer is possible for each frequency band used for radio. In the frequency band management table, a band identifier for identifying a frequency band in which multicast transmission is possible among the first transmission / reception unit 37 and the second transmission / reception unit 38 is associated with an expiration date. The expiration date is the time when the multicast transfer period ends.
Upon receiving the request information, the control unit 32 adds a time (for example, 5 minutes) that is a multicast transfer period to the received time, and calculates an expiration date. Furthermore, when receiving the request information from the second communication unit 31, the control unit 32 specifies whether the output source of the received request information is the first transmission / reception unit 37 or the second transmission / reception unit 38. The control unit 32 determines whether or not a band identifier for identifying a frequency band used by the specified transmission / reception unit 39 (the first transmission / reception unit 37 or the second transmission / reception unit 38) is registered in the frequency band management table. If not registered, the band identifier of the frequency band used by the specified transmission / reception unit 39 is associated with the expiration date and registered in the frequency band management table. If registered, the expiration date associated with the band identifier is updated to the calculated expiration date.
When the control unit 32 does not receive the request information again from the transmission / reception unit 39 associated with the expiration date before the expiration date, the control unit 32 deletes the band identifier and the expiration date from the frequency band management table.
When the first transmission / reception unit 37 receives the multicast data (either the first data or the second data), the control unit 32 uses the frequency band management table to transmit one or more multicast data. The transmission / reception unit 39 is specified. In addition, when the second transmission / reception unit 38 receives the multicast data (third data), the control unit 32 uses the frequency band management table to identify one or more transmission / reception units 39 that can transfer the multicast data. The control unit 32 causes the specified one or more transmission / reception units 39 to transmit multicast data. When the control unit 32 receives data that is not any of the first to third data, that is, receives data of a multicast address group that is not managed by multicast transfer, the control unit 32 does not transfer the data.
As described above, the control unit 32 of the present embodiment determines whether multicast communication is possible for each frequency band used for wireless communication. That is, the frequency band can be regarded as a concept similar to the communication port connected to the cable described in the first embodiment.
Compared to the first embodiment, the overall operation of the control system 10 according to the present embodiment, particularly the operation of transmitting request information, is made by connecting a plurality of devices to one communication port included in the relay device 30. The only difference is that there is no change in the processing content. Therefore, the description about the operation | movement outline | summary of the whole control system 10 of this embodiment is abbreviate | omitted.
Further, the operation of the control device 20 of the present embodiment, particularly the operation of transmitting request information, differs from the first embodiment only in that a plurality of devices are connected to one communication port provided in the relay device 30. There is no change in the processing content. Therefore, the description of the operation of the control device 20 of the present embodiment is also omitted.
As described above, in the control system 10 of the present embodiment, communication is performed wirelessly. The relay device 30 determines whether multicast communication is possible for each frequency band used for wireless communication. Therefore, when the relay device 30 receives the request information from the control device (for example, the control device 20) that uses one frequency band, the relay device 30 sends it to other devices (here, the communication devices 41 and 42) that use the one frequency band. Also, multicast communication is possible. That is, bidirectional multicast communication is possible between the control device 20 and the communication devices 41 and 42.
4 Embodiment 4
In the first embodiment, the multicast transfer period managed by the relay apparatus 30 is uniformly 5 minutes. However, in this embodiment, the multicast transfer period is different for each model (manufacturer) of the relay apparatus 30. .
In the following, the present embodiment will be described focusing on differences from the first embodiment. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.
The control device 20 according to the present embodiment acquires information on the multicast transfer period managed by the relay device 30 using the MAC address of the relay device 30, and transmits request information based on the acquired information on the multicast transfer period. Determine the transmission cycle.
As shown in FIG. 8, the control device 20 of the present embodiment further includes a storage unit 23.
The storage unit 23 stores a transfer period management table in which a manufacturer of a relay apparatus is associated with a multicast transfer period managed by the relay apparatus. The MAC address is represented by 12 digits using a hexadecimal number. Of the 12 digits, the first six digits represent the manufacturer. Therefore, the storage unit 23 also stores a manufacturer management table in which the manufacturer is associated with the first six digits of the MAC address.
The first communication unit 21 transmits an address request for requesting a MAC address to the relay device 30 under the control of the communication processing unit 22, and then receives the MAC address from the relay device 30.
The communication processing unit 22 controls the first communication unit 21 so that the first communication unit 21 transmits an address request and receives a MAC address. When the first communication unit 21 receives the MAC address, the communication processing unit 22 specifies the multicast transfer period managed by the relay device 30 using the MAC address, the manufacturer management table, and the transfer period management table. The communication processing unit 22 controls the first communication unit 21 to transmit the request information by using the time length of the specified multicast transfer period or a time length shorter than the time length as a transmission cycle.
An overall operation outline of the control system 10 of the present embodiment, particularly an operation for determining a transmission cycle of request information will be described with reference to a sequence diagram shown in FIG.
The first communication unit 21 of the control device 20 receives data including, for example, a management protocol from the relay device 30 (step S400).
The communication processing unit 22 of the control device 20 specifies the manufacturer of the relay device 30 from the MAC address included in the received data (step S405). Specifically, the communication processing unit 22 searches the manufacturer management table stored in the storage unit 23 for a numerical value that matches the first six digits of the MAC address included in the received data. If there is a matching numerical value, information on the manufacturer associated with the numerical value is acquired.
The communication processing unit 22 specifies the multicast transfer period managed by the relay device 30 from the specified manufacturer (step S410). Specifically, the communication processing unit 22 searches the transfer period management table stored in the storage unit 23 for a manufacturer that matches the specified manufacturer. If there is a matching manufacturer, the multicast transfer period associated with the manufacturer is specified.
The communication processing unit 22 determines the time length of the specified multicast transfer period or a time length shorter than the time length as the request information transmission cycle (step S415).
The first communication unit 21 transmits the request information at the determined transmission cycle (steps S420 and S425).
Next, the operation of the control device 20, particularly the operation for determining the transmission period of request information and transmitting the request information will be described with reference to the flowchart shown in FIG.
The communication processing unit 22 of the control device 20 acquires the MAC address included in the data received by the first communication unit 21 (step S500).
The communication processing unit 22 specifies the manufacturer of the relay device 30 using the acquired MAC address and manufacturer management table (step S505).
The communication processing unit 22 specifies the multicast transfer period managed by the relay device 30 using the specified manufacturer and transfer period management table (step S510).
The communication processing unit 22 determines a time length that is the same as the time length of the specified multicast transfer period or a time length shorter than the time length as a transmission cycle (step S515).
The communication processing unit 22 causes the first communication unit 21 to transmit request information (step S520).
The communication processing unit 22 determines whether or not the determined transmission cycle has elapsed (step S525).
When determining that the time has elapsed (“Yes” in step S525), the communication processing unit 22 causes the first communication unit 21 to transmit request information (step S530). After the request information is transmitted, the process returns to step S525.
If it is determined that the transmission cycle has not elapsed (“No” in step S525), the communication processing unit 22 waits for the transmission cycle to elapse.
Accordingly, the control device 20 periodically transmits the request information so that the multicast communication period is not interrupted even when the multicast transfer period is different for each manufacturer of the relay device 30. Can do.
In this embodiment, the multicast transfer period and the manufacturer of the relay device 30 are stored in association with each other, but the present invention is not limited to this. The multicast transfer period and the model number of the relay device 30 may be stored in association with each other. That is, the control device 20 only needs to store the multicast transfer period and the information for identifying the relay device 30 in association with each other.
In addition, although the memory | storage part 23 was provided with the control apparatus 20, it is not limited to this. For example, the storage unit 23 may be connected to the control device 20 via a network.
Further, the configurations of Embodiments 2 to 4 can be applied even if they are combined with each other.
5 Embodiment 5
In the first embodiment, the transmission cycle for transmitting the request information is fixed (for example, 3 minutes). However, the present embodiment is different in that the transmission cycle of the request information can be dynamically shortened.
In the following, the present embodiment will be described focusing on differences from the first embodiment. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.
Hereinafter, multicast transfer permission / inhibition information managed by the relay device 30 is referred to as management information.
The communication processing unit 22 transmits the request information at a predetermined transmission cycle. The communication processing unit 22 transmits / receives data to / from the communication devices 41 and 42 via the relay device 30 to determine whether or not the transmission cycle needs to be shortened. Here, the transmitted / received data is, for example, an ECHONET Lite Get request, Get response, INF request, and INF response.
When determining that the transmission cycle needs to be shortened, the communication processing unit 22 determines the currently determined transmission cycle to be a shorter transmission cycle.
Next, an overview of the overall operation of the control system 10 of the present embodiment, in particular, an operation for shortening the request information transmission cycle will be described using the sequence diagram shown in FIG.
The control device 20 transmits the request information to the relay device 30 (step S600).
When a predetermined time T0 (T01) has elapsed since the request information was transmitted in step S600, the control device 20 performs a multicast transfer detection process (step S605). Specifically, the control device 20 transmits a Get request (Get_Request) requesting data (unicast data) transmitted by unicast to the communication device 41 via the relay device 30 (steps S610 and S615). The control device 20 receives the Get response (Get_Response) transmitted by the communication device 41 via the relay device 30 (steps S620 and S625). The control device 20 transmits an INF request (INF_Request) for requesting multicast data to the communication device 41 via the relay device 30 (steps S630 and S6).
35). The control device 20 receives the INF response (INF) transmitted by the communication device 41 via the relay device 30 (steps S640 and S645). Here, the GET request, GET response, and INF request are unicast data, and the INF response is multicast data. Here, the Get request corresponds to unicast data request information, and the INF request corresponds to multicast data request information. The predetermined time T0 is a time obtained by subtracting the processing time length ΔT of the multicast transfer detection process from the transmission cycle T1.
After receiving the INF response, the control device 20 transmits the request information to the relay device 30 when determining that the predetermined time T1 (T11) has elapsed since the request information was transmitted in step S600 (step S650).
Here, it is assumed that the relay device 30 has shortened the time length (transfer permission time) of the multicast transfer period managed by the relay device 30 (step S655). The shortened transfer permission time T2 is shorter than the transmission cycle T1. When the relay device 30 does not receive the request information at the transfer permission time T2 after shortening, the relay device 30 discards the management information (step S660).
When a predetermined time T0 (T02) has elapsed since the request information was transmitted in step S650, the control device 20 performs a multicast transfer detection process (step S665). Specifically, as described above, the control device 20 transmits a Get request, receives a Get response, and transmits an INF request (Steps S670 to S695). Since the relay device 30 discards the management information, the multicast data is not transferred. For this reason, the INF response transmitted by the communication device 41 in step S700 cannot be received.
Since the control device 20 does not receive the INF response in the multicast transfer detection process performed in step S665, the control device 20 shortens the request information transmission cycle (step S705) and transmits the request information to the relay device 30 (step S710). When the predetermined time T4 has elapsed since the request information was transmitted in step S710, the control device 20 performs a multicast transfer detection process (step S715). Here, the predetermined time T4 is a time obtained by subtracting ΔT from the shortened transmission cycle T3.
The control device 20 transmits the request information to the relay device 30 at a transmission cycle corresponding to the result of the multicast transfer detection process (step S720).
In FIG. 11, the transmission cycle T11 and the transmission cycle T12 are depicted as being different from each other for convenience of explanation, but are actually the same cycle. Further, although the predetermined times T01 and T02 and the transfer permission times T21 and T22 are depicted as different in the drawing, they are actually the same time length. In addition, each ΔT described in FIG. 11 is also drawn so that these time lengths are different for convenience of explanation, but in actuality, they are the same time length.
Next, the operation of the control device 20 of the present embodiment, particularly the operation of shortening the request information transmission cycle will be described with reference to the flowchart shown in FIG.
The communication processing unit 22 of the control device 20 causes the first communication unit 21 to transmit request information at the time of activation (step S750).
The communication processing unit 22 determines whether a predetermined time has elapsed (step S755). Here, as described above, the predetermined time is a time obtained by subtracting the processing time length ΔT of the multicast transfer detection process from the transmission period of the request information.
If it is determined that a predetermined time has elapsed since the request information was transmitted (“Yes” in step S755), the communication processing unit 22 performs a multicast transfer detection process (step S760). Specifically, the communication processing unit 22 transmits a Get request and determines whether unicast data (Get response) is received as a response (Step S765).
If it is determined that unicast data has been received (“Yes” in step S765), the communication processing unit 22 transmits an INF request and determines whether multicast data (INF response) has been received as a response (step S765). Step S770).
When determining that the multicast data has not been received (“No” in step S770), the communication processing unit 22 shortens the transmission cycle of the request information (step S775). When multicast data is not received, it is considered that the time length of the multicast transfer period (transfer permission time) has elapsed at the present time, and the management information has been discarded in the relay device 30. Therefore, the control device 20 shortens the request information transmission cycle in order to prevent the management information from being discarded.
When determining that the unicast data has not been received (“No” in step S765), the communication processing unit 22 ends the process.
When it is determined that the multicast data has been received (“Yes” in step S770), the communication processing unit 22 sends the request information to the first communication unit 21 when determining that the transmission cycle has elapsed since the previous request information was transmitted. Transmit (step S780). After the request information is transmitted, the process returns to step S755.
In addition, after shortening the transmission cycle of the request information, the communication processing unit 22 causes the first communication unit 21 to transmit the request information (Step S780). After the request information is transmitted, the process returns to step S755. In this case, the communication processing unit 22 controls the first communication unit 21 to transmit the request information with a shortened transmission cycle.
If it is determined that the predetermined time has not elapsed (“No” in step S755), the process waits for the elapse of the predetermined time.
As a result, even when the time length of the multicast transfer period of the relay device 30 is shortened, the control device 20 periodically transmits the request information so that the period during which communication by multicast is possible is not interrupted. can do.
Further, even when the user does not know the multicast transfer period of the relay device 30, the control device 20 transmits the request information at an optimal transmission cycle in which the management information is not discarded by repeating the multicast transfer detection process. be able to. That is, the control device 20 can transmit the request information with the same length as the time length of the multicast transfer period (transfer permission time) of the relay device 30 or a time length shorter than the transfer permission time as a transmission cycle.
Here, a combination of a function for causing the communication processing unit 22 to transmit request information to the first communication unit 21 and a function for performing a multicast forwarding detection process corresponds to a response detection process.
Normally, transmission / reception of unicast data is performed regardless of control of multicast data transfer by the relay device 30. Therefore, if unicast data cannot be transmitted / received, for example, a physical failure of the communication port of the relay device 30 is considered. For this reason, in this embodiment, the process is terminated when unicast data is not received. In this case, the control device 20 may notify the user of an error message indicating that the relay device 30 has a problem.
In this embodiment, the multicast transfer detection process is performed every transmission period of request information, but the present invention is not limited to this.
When multicast data (INF response) is received by the control device 20 by the multicast transfer detection process, it is not necessary to perform the subsequent multicast transfer detection process every time the request information is transmitted. When multicast data (INF response) is received by the control device 20 by the multicast transfer detection process, the subsequent multicast transfer detection process may be performed in units of one day, one week, or one month. When multicast data is not received by the control device 20 due to the multicast transfer detection process, the control device 20 shortens the transmission period of the request information, and multicast transmission every time the request information is transmitted until multicast data is received. Repeat the detection process. When the multicast data is received, the control device 20 does not perform the subsequent multicast transfer detection process every time the request information is transmitted, but in units such as one day, one week, or one month. .
In this embodiment, the multicast transfer detection process is performed using only the communication device 41. However, when there are a plurality of communication devices, the multicast transfer detection process may be performed on each communication device.
In the present embodiment, the Get request (unicast data request information) is data transmitted by unicast, but the present invention is not limited to this.
The Get request may be transmitted by broadcast.
When the Get request is transmitted by broadcast, there is a disadvantage that there is no guarantee that the Get request is received by all the communication devices 41 and 42. In addition, since Get responses are returned simultaneously from the plurality of communication devices 41 and 42, there is a disadvantage that the control device 20 may not receive all Get responses. However, there is an advantage that a Get request can be delivered to a plurality of communication devices 41 and 42 by a single transmission.
When the Get request is transmitted by unicast, the advantages and disadvantages are opposite to the transmission by broadcast. That is, the Get request transmitted by unicast is reliably transmitted to each of the communication devices 41 and 42, but it is necessary to perform unicast communication for the number of destination communication devices.
Alternatively, the control device 20 may switch between transmission by unicast and transmission by broadcast according to the number of communication devices that transmit a Get request. In this case, the control device 20 stores the number of communication devices to be communicated. The communication processing unit 22 selects transmission by unicast if the number of stored communication devices is less than the threshold, and selects transmission by broadcast if the number of stored communication devices is equal to or greater than the threshold. . Alternatively, the communication processing unit 22 may select transmission by unicast or transmission by broadcast by a user operation.
In addition, when the transmission by broadcast is selected, the communication processing unit 22 may cause the first communication unit 21 to repeat the Get request transmission a plurality of times. For example, when the control device 20 and the communication devices 41 and 42 are communicating wirelessly via the relay device 30, a communication device that cannot receive a Get response or a Get response is sent to the relay device 30 depending on radio wave conditions. There may be communication devices that do not reach. Therefore, the communication processing unit 22 can improve the accuracy of confirmation of the Get response to the Get request transmitted by broadcasting by causing the first communication unit 21 to transmit the Get request multiple times by broadcasting.
Further, the communication processing unit 22 may cause the first communication unit 21 to repeatedly transmit an INF request (multicast data request information) a plurality of times by multicast. Thereby, the accuracy of confirmation of the INF response to the INF request transmitted by multicast can be improved.
Further, the configurations of the second to fifth embodiments can be applied even when combined with each other.
6 Embodiment 6
In the fifth embodiment, a request information transmission cycle is determined by including a multicast data transfer detection process in a normal process for periodically transmitting request information. This embodiment is different from the fifth embodiment in that a process for determining the transmission cycle of request information is performed separately from the normal process.
In the following, the present embodiment will be described focusing on differences from the fifth embodiment. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 5, and description is abbreviate | omitted suitably.
The communication processing unit 22 transmits the request information to the first communication unit 21 at the time of activation, and performs the above-described multicast transfer detection process when a predetermined time has elapsed since the transmission of the request information. Here, the predetermined time is, for example, a transmission cycle set at the present time. In the multicast transfer detection process, the communication processing unit 22 shortens the predetermined time when multicast data (INF response) is not received. The communication processing unit 22 performs the request information transmission and the multicast transfer detection process described above until the multicast data (INF response) is received.
When multicast data is received, the communication processing unit 22 sets a predetermined time set at that time as a transmission cycle. The communication processing unit 22 controls the first communication unit 21 to transmit the request information at the determined transmission cycle.
In addition, the communication processing unit 22 performs a process (determination process) for periodically determining whether multi-data can be received from the communication devices 41 and 42, and determines that the multi-data cannot be received in the determination process. The transmission cycle is determined in the same manner as when starting up.
Next, an overall operation overview of the control system 10 according to the present embodiment, particularly an operation for shortening the transmission cycle of request information will be described with reference to the sequence diagram shown in FIG.
The control device 20 transmits request information to the relay device 30 at the time of activation (step S800).
When a predetermined time T5 has elapsed since the request information was transmitted in step S600, the control device 20 performs a multicast transfer detection process (step S805). Specifically, the control device 20 controls the first communication unit to transmit a Get request (Get_Request) for requesting unicast data to the communication device 41 via the relay device 30 (steps S810 and S815). The control device 20 controls the first communication unit 21 to receive the Get response (Get_Response) transmitted by the communication device 41 via the relay device 30 (steps S820 and S825). The control device 20 controls the first communication unit 21 to transmit an INF request (INF_Request) for requesting multicast data to the communication device 41 via the relay device 30 (steps S830 and S835). Here, the Get request corresponds to unicast data request information, and the INF request corresponds to multicast data request information.
Here, it is assumed that the control device 20 cannot receive the INF response (INF) from the communication device 41 (step S840).
When the control device 20 cannot receive the INF response from the communication device 41, the control device 20 shortens the predetermined time T5 (step S845). The predetermined time after shortening is described as T6. When multicast data is not received, it is considered that the time length of the multicast transfer period (transfer permission time) has elapsed at the present time, and the management information has been discarded in the relay device 30. Therefore, the control device 20 shortens the request information transmission cycle in order to prevent the management information from being discarded.
The control device 20 transmits the request information to the relay device 30 (step S850).
When the predetermined time T6 has elapsed since the request information was transmitted in step S600, the control device 20 performs a multicast transfer detection process (step S855). Specifically, as described above, the control device 20 controls the first communication unit to transmit a Get request, receive a Get response, and transmit an INF request (Steps S860 to S890).
Here, the control device 20 receives the INF response from the communication device 41 by shortening the predetermined time (steps S890 and S895).
Next, the operation of the control device 20 of the present embodiment, particularly the operation of shortening the transmission cycle, will be described with reference to the flowchart shown in FIG.
The communication processing unit 22 of the control device 20 causes the first communication unit 21 to transmit request information at the time of activation (step S900).
The communication processing unit 22 determines whether or not a predetermined time (T5) has elapsed (step S905).
If it is determined that a predetermined time has elapsed since the request information was transmitted (“Yes” in step S905), the communication processing unit 22 performs a multicast transfer detection process (step S910). Specifically, the communication processing unit 22 transmits a Get request to the first communication unit 21, and determines whether or not the first communication unit 21 has received unicast data (Get response) as a response (Step). S915).
If it is determined that unicast data has been received (“Yes” in step S915), the communication processing unit 22 causes the first communication unit 21 to transmit an INF request, and whether multicast data (INF response) has been received as a response. It is determined whether or not (step S920).
When determining that the multicast data has been received (“Yes” in step S920), the communication processing unit 22 determines the predetermined time set at the present time as the transmission cycle (step S925). The communication processing unit 22 controls the first communication unit 21 so as to transmit the request information at the determined transmission cycle.
When determining that the multicast data has not been received (“No” in step S920), the communication processing unit 22 shortens the predetermined time (step S930) and causes the first communication unit 21 to transmit the request information (step S935). ). After the request information is transmitted, the process returns to step S905. In this case, the determination process in step S905 is performed using the shortened predetermined time.
If it is determined that the predetermined time has not elapsed (“No” in step S905), the process waits for the elapse of the predetermined time.
13 and 14, the control device 20 determines the transmission cycle at the time of activation. However, also when it is detected by the above-described determination process that multicast data cannot be received, the control device 20 can determine the transmission cycle in the same process flow.
Thereby, the control apparatus 20 can determine the transmission period of request information so that the communicable period by multicast may not be interrupted.
Also in the present embodiment, as in the fifth embodiment, when the unicast data cannot be transmitted / received, the control device 20 may notify the user of an error message indicating that the relay device 30 is defective.
Also in the present embodiment, as in the fifth embodiment, the Get request may be transmitted by broadcast.
7 Embodiment 7
In the present embodiment, a control system 10 in which the fifth embodiment and the sixth embodiment are combined will be described.
First, a case will be described in which a relay device 30 is newly installed in the control system 10 of the present embodiment or an existing relay device is replaced with a new relay device 30.
In this case, since the control device 20 has not acquired any information about the new relay device 30, the control device 20 has not acquired any information on the multicast transfer period set in the relay device 30. Therefore, before the control device 20 periodically transmits the request information, the control device 20 sets the transmission cycle so that the transmission cycle of the request information is equal to or less than the time length of the multicast transfer period of the new relay device 30. It is necessary to decide.
Therefore, in the present embodiment, the control device 20 performs the process (determination process) for determining the request information transmission cycle described in the sixth embodiment before the periodic transmission of the request information.
Specifically, the communication processing unit 22 of the control device 20 first transmits request information to the first communication unit 21 as shown in step S900 of FIG. The communication processing unit 22 performs multicast transfer detection processing when a predetermined time stored in advance in the control device 20 has elapsed (see step S910 in FIG. 14).
If the multicast data (INF request) is not received in the multicast transfer detection process, the communication processing unit 22 shortens the predetermined time and transmits the request information to the first communication unit 21 again (steps S930 and S935 in FIG. 14). reference).
When multicast data is received in the multicast transfer detection process, the communication processing unit 22 determines a predetermined time set at that time as a transmission cycle.
As a result, even when the control device 20 has not acquired information on the multicast transfer period set by the new relay device 30, the transmission cycle is set to be equal to or less than the time length of the multicast transfer period of the relay device 30. Can be determined.
Next, in the present embodiment, a case will be described in which the control device 20 transmits the request information at the transmission cycle determined by the determination process described above.
In the present embodiment, when the transmission cycle is determined in the determination process, the communication processing unit 22 periodically transmits request information to the first communication unit 21 based on the process illustrated in FIG.
Specifically, the communication processing unit 22 first transmits request information to the first communication unit 21 as shown in step S750 of FIG. After transmitting the request information, the communication processing unit 22 performs a multicast transfer detection process when a predetermined time has elapsed. The predetermined time here is a time obtained by subtracting the processing time length (for example, ΔT) of the multicast forwarding detection process from the transmission cycle (for example, T1) as described in the fifth embodiment.
If multicast data (INF request) is not received in the multicast transfer detection process, the transmission cycle is shortened and the request information is transmitted again to the first communication unit 21 (see steps S775 and S780 in FIG. 12).
When multicast data is received in the multicast transfer detection process, the communication processing unit 22 causes the first communication unit 21 to transmit subsequent request information at the transmission cycle set at that time.
Thereby, the control apparatus 20 can shorten a transmission period, even after a transmission period is determined by the determination process.
Further, as described in the fifth embodiment, in this embodiment as well, it is not necessary to perform the multicast transfer detection process for each request information transmission cycle. For example, as described in the fifth embodiment, when multicast data (INF response) is received by the control device 20 by the multicast transfer detection process, the subsequent multicast transfer detection process is performed one day later, one week later, or 1 It may be done in units such as months later. When multicast data is not received by the control device 20 due to the multicast transfer detection process, the control device 20 shortens the transmission period of the request information, and multicast transmission every time the request information is transmitted until multicast data is received. Repeat the detection process. When the multicast data is received, the control device 20 does not perform the subsequent multicast transfer detection process every time the request information is transmitted, but in units such as one day, one week, or one month. .
Also in the present embodiment, as in the fifth and sixth embodiments, the Get request may be transmitted by broadcast.
8. Embodiment 8
In the first embodiment, the control device 20 periodically transmits the request information. However, in this embodiment, in addition to the request information, the control information is also periodically transmitted to request the request information to be transmitted to the relay device 30. The point of sending is different. The inquiry information is, for example, IGMP Query as described above.
In the following, the present embodiment will be described focusing on differences from the first embodiment. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.
The first communication unit 21 according to the present embodiment transmits inquiry information to the communication devices 41 and 42 via the relay device 30 under the control of the communication processing unit 22. The inquiry information may be transmitted at the same timing as the request information is transmitted to the relay device 30 or at a different timing.
The communication processing unit 22 controls the first communication unit 21 so as to transmit inquiry information (IGMP Query) by multicast. Here, the IGMP Query is stipulated in the IGMP standard so that multicast transmission is performed in the relay device even for communication ports that are not permitted to transfer multicast data. Therefore, in this embodiment, when the relay apparatus 30 transmits inquiry information (IGMP Query), the received inquiry information is transferred to the communication ports 34 and 35 to which the communication apparatuses 41 and 42 are connected. Thereby, the communication apparatuses 41 and 42 can receive inquiry information.
When the communication devices 41 and 42 receive the inquiry information and wish to receive multicast data addressed to a specific group, the communication devices 41 and 42 send request information (IGMP Report) including the multicast address desired to be received to the control device 20 to the relay device 30. Notify via
When receiving the inquiry information, the control unit 32 of the relay device 30 transmits the inquiry information to the communication devices 41 and 42. When the control unit 32 acquires the multicast address included in the request information by IGMP Snooping, the control unit 32 permits the communication port that has received the request information to transfer multicast data until the multicast transfer period elapses.
Next, an overall operation overview of the control system 10 of the present embodiment, in particular, an operation for transmitting request information and inquiry information will be described with reference to a sequence diagram shown in FIG.
The control device 20 transmits inquiry information to the communication devices 41 and 42 via the relay device 30 at the time of activation (steps S1000 to S1010).
The communication devices 41 and 42 that have received the inquiry information transmit request information to the relay device 30 as a response to the inquiry information when they wish to receive multicast data addressed to a specific group (steps S1015 and S1020).
After transmitting the inquiry information, the control device 20 transmits the request information to the relay device 30 (step S1025).
When the transmission cycle T1 (T15) ends, in the next transmission cycle T1 (T16), the control device 20 transmits inquiry information to the communication devices 41 and 42 via the relay device 30 (steps S1030 to S1040). .
The communication devices 41 and 42 that have received the inquiry information transmit request information to the relay device 30 if they wish to receive multicast data addressed to a specific group (steps S1045 and S1050).
After transmitting the inquiry information, the control device 20 transmits the request information to the relay device 30 (step S1055).
When the transmission cycle T1 (T16) ends, in the next transmission cycle T1 (T17), the control device 20 transmits inquiry information to the communication devices 41 and 42 via the relay device 30 (steps S1060 to S1070). .
The communication devices 41 and 42 that have received the inquiry information transmit request information to the relay device 30 when they wish to receive multicast data addressed to a specific group (steps S1075 and S1080).
After transmitting the inquiry information, the control device 20 transmits the request information to the relay device 30 (step S1085).
Next, the operation of the control device 20 of the present embodiment, particularly the operation of transmitting request information and inquiry information will be described with reference to the flowchart shown in FIG.
The communication processing unit 22 of the control device 20 causes the first communication unit 21 to transmit inquiry information and request information at the time of activation (steps S1100 and S1105).
The communication processing unit 22 determines whether a predetermined time has elapsed (step S1110). The predetermined time here is a request information transmission cycle.
When determining that the predetermined time has passed (“Yes” in step S1110), the communication processing unit 22 causes the first communication unit 21 to transmit inquiry information and request information (steps S1115 and S1120). After the inquiry information and request information are transmitted, the process returns to step S1110.
If it is determined that the predetermined time has not elapsed (“No” in step S1110), the process waits for the elapse of the predetermined time.
As described above, the control device 20 transmits the request information to the communication devices 41 and 42 connected to different communication ports in the relay device 30 by periodically transmitting the inquiry information. Therefore, the relay device 30 can transfer multicast data not only to the control device 20 but also to the communication devices 41 and 42.
In addition, although the control apparatus 20 transmitted inquiry information as multicast data, when the information of the address of the communication apparatuses 41 and 42 is acquired, you may transmit as unicast data. Or the control apparatus 20 may transmit inquiry information by broadcast.
9 Other variations
Although the present invention has been described based on the first to sixth embodiments, the present invention is not limited to the above-described embodiments. For example, the following modifications can be considered.
(1) In the above embodiments, only the control device 20 transmits the request information. However, the present invention is not limited to this. The communication devices 41 and 42 may also periodically send request information.
(2) In the first embodiment, each of the communication ports 33 to 35 is connected to one device (the control device 20, the communication devices 41 and 42), but is not limited thereto.
At least one of the communication ports 33 to 35 may be connected to another relay device. In this case, the relay device 30 can transmit multicast data to one or more devices connected to other relay devices.
(3) Although the number of communication ports is three in the first embodiment, the present invention is not limited to this. The number of communication ports may be two or more.
In the second embodiment, the two frequency bands used for the wireless communication are the first frequency band and the second frequency band. However, the present invention is not limited to this. One or more frequency bands may be used for wireless communication.
In this case, the second communication unit 31 includes a transmission / reception unit according to the number of frequency bands used for wireless communication, for example.
(4) In the second embodiment, the control device 20 starts the periodic transmission of request information at the time of activation, but is not limited to this.
After receiving the inquiry information, the communication processing unit 22 of the control device 20 may start periodic transmission of the request information when the next inquiry information is not received within a predetermined time (for example, within 5 minutes). .
(5) In the first embodiment, the relay device 30 may periodically output inquiry information (IGMP Query).
In this case, until the inquiry information is received from the relay device 30, the control device 20 transmits the request information to the relay device 30 periodically (for example, every 3 minutes) as in the first embodiment. When receiving the inquiry information, the control device 20 transmits the request information to the relay device 30, and then stops transmitting the request information periodically.
(6) You may combine the said embodiment and modification.
10 Summary
As described above, the control device 20 communicates with the one or more communication devices 41 and 42 to be controlled via the relay device 30 and controls the one or more communication devices 41 and 42. The relay device 30 permits the transfer of data to the communication path that has received the request information after receiving the request information for requesting the transfer of the data transmitted by multicast until the end of the multicast transfer period. . Here, the communication path is, for example, the communication ports 33 to 35, the first transmission / reception unit 37, and the second transmission / reception unit 38. The control device 20 includes a first communication unit 21 (communication unit) that performs communication with the relay device 30 and communication with one or more communication devices 41 and 42 via the relay device 30, and a communication processing unit 22. Prepare. The communication processing unit 22 causes the first communication unit 21 to transmit the request information within the multicast transfer period.
According to this configuration, the control device 20 transmits the request information within the multicast transfer period. Usually, a device (control device 20) having higher processing performance than other devices (communication devices 41 and 42) controls the other devices. Therefore, even if the control device 20 periodically transmits the request information within the multicast transfer period, the processing load is low compared to the case where the other device performs. That is, the control device 20 can perform multicast communication while preventing a decrease in reliability of the entire system.
Here, it is preferable that the control device 20 includes a storage unit that stores identification information for identifying the relay device 30 and a multicast transfer period in association with each other. The first communication unit 21 receives identification information (a numerical value of the first six digits of the MAC address) for identifying the relay device 30. The communication processing unit 22 specifies the multicast transfer period corresponding to the identification information received by the first communication unit 21 and causes the first communication unit 21 to transmit the request information within the specified multicast transfer period.
According to this configuration, the control device 20 can periodically transmit the request information so that the multicast communication period is not interrupted even when the multicast transfer period is different for each relay device 30. .
Here, the communication processing unit 22 performs a response detection process. In the response detection process, request information is transmitted to the first communication unit 21, and when a predetermined time has elapsed, at least one of the one or more communication devices 41 and 42 is requested to send multicast data. This is processing for transmitting data request information to the first communication unit. When the first communication unit 21 does not receive multicast data, the communication processing unit 22 performs a response detection process by shortening the predetermined time. When receiving the multicast data, the communication processing unit 22 controls the first communication unit 21 to transmit the request information at a transmission period corresponding to a predetermined time set at that time.
According to this configuration, since the control device 20 dynamically shortens the transmission period of the request information, the request information is periodically updated so that the multicast communication period is not interrupted according to the multicast transfer period of the relay device 30. Can be transmitted.
Here, in the response detection process, the communication processing unit 22 transmits unicast data request information for requesting transmission of unicast data to at least one communication device among the one or more communication devices 41 and 42. 21 to transmit. The communication processing unit 22 shortens the predetermined time when the first communication unit 21 receives unicast data and does not receive multicast data.
According to this configuration, the control device 20 can shorten the transmission cycle only when the relay device 30 controls the transfer of data transmitted by multicast to the communication path. This is because, normally, when the control device 20 cannot receive both unicast data and multicast data, a failure of the relay device 30 itself can be considered.
Here, the communication processing unit 22 further transmits inquiry information for requesting transmission of the request information to the relay device 30 to the first communication unit 21 within one multicast transmission period to one or more communication devices 41 and 42. It is preferable to make it.
According to this configuration, the control device 20 can transfer multicast data not only to the device itself but also to other devices (communication devices 41 and 42) that request the transfer of multicast data.
Here, the first communication unit 21 preferably performs communication with the relay device 30 and communication with the one or more communication devices 41 and 42 via the relay device 30 by wireless communication using a frequency band. . The relay device 30 controls transfer of data transmitted by multicast using a radio path using a frequency band as a communication path.
According to this configuration, the control device 20 can transmit the request information to the relay device 30 by wireless communication. Therefore, the relay device 30 enables multicast data to be transferred to the communication devices 41 and 42 that use the same frequency band as that used by the control device 20 in wireless communication. That is, bidirectional multicast communication is possible between the control device 20 and the communication devices 41 and 42.
The program of the present application is a program for causing a computer to function as any one of the control devices 20 described above.
According to this program, multicast communication can be performed while preventing a decrease in the reliability of the entire system.

Claims (7)

  1.  マルチキャストで送信されたデータの転送を依頼する依頼情報を受信してからマルチキャスト転送期間が終了するまでの間は当該依頼情報を受信した通信経路に対して前記データの転送を許可する中継装置を介して、制御対象である1つ以上の通信装置と通信し、前記1つ以上の通信装置の制御を行う制御装置であって、
     前記中継装置との通信、および前記中継装置を介した前記1つ以上の通信装置との通信を行う通信部と、
     通信処理部とを備え、
     前記通信処理部は、
     前記依頼情報を前記マルチキャスト転送期間内に前記通信部に送信させる
     ことを特徴とする制御装置。
    From the time when the request information for requesting transfer of data transmitted by multicast is received until the end of the multicast transfer period, the request is transmitted via a relay device that permits the transfer of the data to the communication path that received the request information. A control device that communicates with one or more communication devices to be controlled and controls the one or more communication devices,
    A communication unit that communicates with the relay device and communicates with the one or more communication devices via the relay device;
    A communication processing unit,
    The communication processing unit
    The control apparatus, wherein the request information is transmitted to the communication unit within the multicast transfer period.
  2.  前記中継装置は複数個設けられており、
     前記中継装置を識別する識別情報と、前記マルチキャスト転送期間とを対応付けて記憶する記憶部を備え、
     前記通信部は、前記中継装置を識別する識別情報を受信し、
     前記通信処理部は、前記通信部が受信した前記識別情報に対応する前記マルチキャスト転送期間を特定し、前記依頼情報を特定した前記マルチキャスト転送期間内に前記通信部に送信させる
     ことを特徴とする請求項1に記載の制御装置。
    A plurality of the relay devices are provided,
    A storage unit for storing the identification information for identifying the relay device and the multicast transfer period in association with each other;
    The communication unit receives identification information for identifying the relay device;
    The communication processing unit specifies the multicast transfer period corresponding to the identification information received by the communication unit, and causes the communication unit to transmit the request information within the specified multicast transfer period. Item 2. The control device according to Item 1.
  3.  前記通信処理部は、
     前記依頼情報を前記通信部に送信させて、所定時間が経過すると、前記1つ以上の通信装置のうち少なくとも1つの通信装置に、マルチキャストデータの送信を要求するマルチキャストデータ要求情報を前記通信部に送信させる応答検出処理を行い、前記通信部がマルチキャストデータを受信しない場合には、前記所定時間を短縮して、前記応答検出処理を行い、
     前記マルチキャストデータを受信した場合には、その時点で設定されている前記所定時間に応じた送信周期で、前記依頼情報を送信するように前記通信部を制御する
     ことを特徴とする請求項1または請求項2に記載の制御装置。
    The communication processing unit
    When the request information is transmitted to the communication unit and a predetermined time elapses, multicast data request information for requesting transmission of multicast data to at least one communication device of the one or more communication devices is transmitted to the communication unit. When performing response detection processing to be transmitted and the communication unit does not receive multicast data, the predetermined time is shortened and the response detection processing is performed.
    The communication unit is controlled to transmit the request information at a transmission cycle corresponding to the predetermined time set at that time when the multicast data is received. The control device according to claim 2.
  4.  前記通信処理部は、前記応答検出処理において、前記少なくとも1つの通信装置に、ユニキャストデータの送信を要求するユニキャストデータ要求情報を前記通信部に送信させ、前記通信部が、ユニキャストデータを受信し、かつ前記マルチキャストデータを受信しない場合には、前記所定時間を短縮する
     ことを特徴とする請求項3に記載の制御装置。
    In the response detection process, the communication processing unit causes the at least one communication device to transmit unicast data request information requesting transmission of unicast data to the communication unit, and the communication unit transmits unicast data. The control apparatus according to claim 3, wherein the predetermined time is shortened when receiving and not receiving the multicast data.
  5.  前記通信処理部は、さらに、依頼情報を前記中継装置へ送信するように要求する問合せ情報を、前記1つ以上の通信装置へ前記マルチキャスト転送期間内に前記通信部に送信させる
     ことを特徴とする請求項1乃至請求項4のいずれか一項に記載の制御装置。
    The communication processing unit further causes the one or more communication devices to transmit inquiry information requesting transmission of request information to the relay device to the communication unit within the multicast transfer period. The control apparatus as described in any one of Claims 1 thru | or 4.
  6.  前記通信部は、
     周波数帯域を用いた無線経路を前記通信経路としてマルチキャストで送信された前記データの転送を制御する前記中継装置との通信、および前記中継装置を介した前記1つ以上の通信装置との通信を、前記周波数帯域を用いた無線通信で行う
     ことを特徴とする請求項1乃至請求項4のいずれか一項に記載の制御装置。
    The communication unit is
    Communication with the relay device that controls transfer of the data transmitted by multicast using a wireless path using a frequency band as the communication route, and communication with the one or more communication devices via the relay device, The control device according to any one of claims 1 to 4, wherein the control device performs wireless communication using the frequency band.
  7.  コンピュータを、請求項1乃至請求項6のいずれか1項に記載の制御装置として機能させるためのプログラム。 A program for causing a computer to function as the control device according to any one of claims 1 to 6.
PCT/IB2015/001645 2014-09-18 2015-09-18 Control device and program WO2016042385A1 (en)

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WO2015108106A1 (en) * 2014-01-16 2015-07-23 日本電気株式会社 Packet transfer device, control device, communication system, communication method, and program

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US20150288733A1 (en) * 2014-04-08 2015-10-08 Comcast Cable Communications, Llc Dynamically Switched Multicast Delivery
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