JP7215483B2 - Communication systems and monitoring equipment - Google Patents

Description

The present invention relates to communication systems and monitoring devices.
This application claims priority based on Japanese Patent Application No. 2018-139465 filed on July 25, 2018, and incorporates all of its disclosure herein.

As an example of a network system, for example, Japanese Patent No. 6046480 (Patent Document 1) discloses the following configuration.

That is, the network system includes a radio station installed in each tower of a tower row on which transmission lines are installed, and a master station connectable to an external communication line to at least one of the radio stations. information can be sequentially relayed bi-directionally from the radio station to the master station or from the master station to the radio station along the tower train by a first communication memory for storing the sent information; and a second communication memory for storing the information sent from the other side of the tower train, wherein the first communication In a power transmission tower maintenance information wireless network system that relays the information stored in the second communication memory to the other side and relays the information stored in the second communication memory to the one side, the radio station has An identification number is assigned individually, and the radio station that is the source of the information transmits the information with the identification number of its own station attached, and the master station transmits the identification number of the radio station. It has an identification number conversion table that associates the numbers with the tower numbers assigned to the towers on which the radio stations are installed. A plurality of tower numbers corresponding to each transmission line are assigned to the tower, and the master station converts the identification number of the radio station that transmitted the information to each of the transmission lines based on the identification number conversion table. is converted into a plurality of tower numbers corresponding to . A parent station communicates with a higher-level host station via an external communication line such as a mobile phone line.

Japanese Patent No. 6046480

(1) A communication system of the present disclosure is a communication system that is used in a power system and includes a plurality of monitoring devices, wherein different terminal identifiers are fixedly assigned to the plurality of monitoring devices, and the plurality of The monitoring device is capable of transferring information to another monitoring device having the pre-registered first terminal identifier, and the monitoring device for which transfer of information to the other monitoring device fails is a pre-registered monitoring device. forwarding information to the other said monitoring device having the second said terminal identifier.

(6) The monitoring device of the present disclosure is used in a power system and is a monitoring device in a communication system including a plurality of monitoring devices, wherein different terminal identifiers are fixedly assigned to the plurality of monitoring devices. , a storage unit for storing the terminal identifier; and a communication unit for transferring information to the other monitoring device having the first terminal identifier registered in advance, wherein the communication unit transfers the information to the other monitoring device. If the transfer of the information fails, the information is transferred to the other monitoring device having the pre-registered second terminal identifier.

One aspect of the present disclosure can be implemented not only as a communication system including such a characteristic processing unit, but also as a method including steps of such characteristic processing, or by causing a computer to execute such steps. It can be implemented as a program for Also, one aspect of the present disclosure can be implemented as a semiconductor integrated circuit that implements part or all of a communication system.

In addition, one aspect of the present disclosure can be implemented not only as a monitoring device including such a characteristic processing unit, but also as a method having steps of such characteristic processing, or by executing such steps in a computer. It can be implemented as a program for execution. Also, one aspect of the present disclosure can be implemented as a semiconductor integrated circuit that implements part or all of the monitoring device.

FIG. 1 is a diagram showing the configuration of a communication system according to an embodiment of the invention. FIG. 2 is a diagram showing an application example of the communication system according to the embodiment of the present invention. FIG. 3 is a block diagram showing the configuration of the monitoring master device in the communication system according to the embodiment of the invention. FIG. 4 is a block diagram showing the configuration of the supervisory device in the communication system according to the embodiment of the invention. FIG. 5 is a diagram showing an example of address allocation in the communication system according to the embodiment of the invention. FIG. 6 is a diagram showing an example of first list information held by a host device in the communication system according to the embodiment of the invention. FIG. 7 is a diagram showing an example of second list information held by a host device in the communication system according to the embodiment of the present invention. FIG. 8 is a diagram showing an example of first list information held by the collection device in the communication system according to the embodiment of the invention. FIG. 9 is a diagram showing an example of first list information held by the collection device in the communication system according to the embodiment of the invention. FIG. 10 is a diagram showing an example of the second list information held by the collecting device, monitoring parent device, and monitoring child device in the communication system according to the embodiment of the present invention. FIG. 11 is a diagram showing an example of the second list information held by the collecting device, monitoring parent device, and monitoring child device in the communication system according to the embodiment of the present invention. FIG. 12 is a diagram showing an example of essential parts of a packet in the communication system according to the embodiment of the invention. FIG. 13 is a diagram showing an example of packets used between a host device and a collection device in the communication system according to the embodiment of the invention. FIG. 14 is a diagram showing an example of packets used between the collection device and the wireless master device in the communication system according to the embodiment of the present invention. FIG. 15 is a diagram showing an example of radio packets used between monitoring devices in the communication system according to the embodiment of the present invention. FIG. 16 is a diagram showing an example of an information transmission sequence in the communication system according to the embodiment of the present invention. FIG. 17 is a diagram showing an example of a wireless packet transfer method between monitoring devices in the communication system according to the embodiment of the present invention. FIG. 18 is a diagram showing an example of a skip setting table held by each monitoring device in the communication system according to the embodiment of the invention. FIG. 19 is a diagram showing an example of a skip information table held by each monitoring device in the communication system according to the embodiment of the invention. FIG. 20 is a diagram showing an example of a sequence in which the monitoring device in the communication system according to the embodiment of the present invention skips transfer destinations of wireless packets. FIG. 21 is a flow chart defining an example of an operation procedure when the monitoring device in the communication system according to the embodiment of the present invention transfers wireless packets. FIG. 22 is a diagram showing an example of processing when the monitoring device in the communication system according to the embodiment of the present invention receives wireless packets with the same content multiple times. FIG. 23 is a diagram showing an example of a reception history table held by each monitoring device in the communication system according to the embodiment of the invention. FIG. 24 is a diagram showing an example of a discard condition table held by each monitoring device in the communication system according to the embodiment of the invention. FIG. 25 is a flow chart showing an example of an operation procedure when the monitoring device in the communication system according to the embodiment of the present invention receives wireless packets.

[Problems to be Solved by the Present Disclosure]
In the network system described in Patent Document 1, each radio station transmits information to adjacent radio stations. Thereby, sequential relay communication is performed.

A technique capable of achieving stable operation is desired, which surpasses the technique described in Patent Document 1 as described above.

The present disclosure has been made to solve the above-described problems, and an object thereof is to provide a communication system and a monitoring device capable of realizing more stable operation in a power system.

[Effect of the present disclosure]
According to the present disclosure, it is possible to realize more stable operation in a power system.

[Description of Embodiments of the Present Invention]
First, the contents of the embodiments of the present invention will be listed and explained.

(1) A communication system according to an embodiment of the present invention is used in a power system and includes a plurality of monitoring devices, wherein different terminal identifiers are fixedly assigned to the plurality of monitoring devices. wherein the plurality of monitoring devices are capable of transferring information to another monitoring device having the first terminal identifier registered in advance, and the monitoring device for which transfer of information to the other monitoring device has failed forwards the information to the other said monitoring device having the pre-registered second said terminal identifier.

In this manner, different terminal identifiers are fixedly assigned to a plurality of monitoring devices, and each monitoring device transfers information to another monitoring device having a pre-registered terminal identifier. can be transmitted. In addition, when the monitoring device fails to transfer information to another monitoring device having the first terminal identifier, the configuration for transferring information to another monitoring device having the second terminal identifier enables, for example, the next-stage Even if information cannot be transferred to the monitoring device, the information can be transmitted to other monitoring devices after the next stage by skipping the next monitoring device. As a result, delays in information transfer can be prevented, and information can be transmitted more reliably. Therefore, more stable operation can be realized in the power system.

(2) Preferably, the monitoring device that fails to transfer information to the other monitoring device having the second terminal identifier has the third terminal identifier registered in advance. transfer information to

With such a configuration, for example, when the information cannot be transferred even if the monitoring device at the next stage is skipped, the information can be transmitted to the other monitoring device by skipping the monitoring device. can be transmitted.

(3) Preferably, the monitoring device generates a packet containing the terminal identifier of the monitoring device and a sequence number as a transmission source and transmits the packet to another monitoring device, and the monitoring device newly receives If the terminal identifier and the sequence number contained in the packet respectively overlap with the terminal identifier and the sequence number contained in the received packet, the newly received packet is discarded.

With such a configuration, for example, it is possible to prevent a plurality of monitoring devices from transferring packets with the same content due to packet retransmission, thereby preventing a large number of unnecessary packets from being transmitted between monitoring devices.

(4) Preferably, the monitoring device transfers measurement information indicating the measurement result of the sensor in the monitoring device and transfer measurement information indicating the measurement result of the sensor in the other monitoring device received from the other monitoring device. Do at least one of

With such a configuration, it is possible to prevent the transmission of the measurement information indicating the measurement result of the sensor from being delayed, and to transmit the measurement information more reliably. Therefore, for example, in an electric power system, it is possible to more reliably transmit information indicating lightning strike positions and the like to power transmission equipment.

(5) Preferably, the plurality of monitoring devices include a monitoring parent device that performs multi-hop communication, and a plurality of monitoring child devices capable of communicating with the monitoring parent device, and each of the monitoring child devices communicates with the monitoring parent device. For each of the upstream direction to the device and the downstream direction from the monitoring parent device to each of the monitoring child devices, each of the monitoring child devices separately holds the first terminal identifier and the second terminal identifier. the first terminal identifier held by each supervisory device is exclusive in each of the uplink and the downlink, and each of the supervisory devices in each of the uplink and the downlink The second terminal identifier held by is assigned to the supervisory child device positioned after the supervisory device to which the first terminal identifier is assigned.

With such a configuration, the physically closest monitoring device can be set as the first transfer destination in the uplink direction and the downlink direction along the direction in which the plurality of monitoring devices are arranged. The certainty of information transmission can be enhanced.

(6) A monitoring device according to an embodiment of the present invention is a monitoring device in a communication system that is used in a power system and includes a plurality of monitoring devices, wherein different terminal identifiers are fixed to the plurality of monitoring devices. and a storage unit for storing the terminal identifier, and a communication unit for transferring information to the other monitoring device having the first terminal identifier registered in advance, the communication unit comprising the If the transfer of information to another monitoring device fails, the information is transferred to the other monitoring device having the pre-registered second terminal identifier.

In this manner, different terminal identifiers are fixedly assigned to a plurality of monitoring devices, and the communication unit transfers information to other monitoring devices having pre-registered terminal identifiers. can be transmitted. Further, when the communication unit fails to transfer information to another monitoring device having the first terminal identifier, the configuration transfers information to another monitoring device having the second terminal identifier. Even if information cannot be transferred to the monitoring device, the information can be transmitted to other monitoring devices after the next stage by skipping the next monitoring device. As a result, delays in information transfer can be prevented, and information can be transmitted more reliably. Therefore, more stable operation can be realized in the power system.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated. Moreover, at least part of the embodiments described below may be combined arbitrarily.

[Configuration and basic operation]
FIG. 1 is a diagram showing the configuration of a communication system according to an embodiment of the invention.

Referring to FIG. 1, communication system 301 is a communication system used in a power system. Specifically, the communication system 301 is, for example, a communication system installed together with a power transmission facility installed between a power plant and an electric power consumer, for example, detecting a lightning strike position on the power transmission facility, It is used for temperature monitoring and maintenance of power transmission equipment.

A communication system 301 includes one or more monitoring systems T and a host device 181 . A monitoring system T includes a collection device 151 and one or more monitoring devices 101 . In the example shown in FIG. 1, the communication system 301 has two monitoring systems T1 and T2 as the monitoring system T. In the example shown in FIG.

The monitoring device 101 has a function of transferring information. In this specification, "transfer" includes, for example, relaying information to a relay destination, and transmitting information to a relay destination as a source of information.

Specifically, the monitoring device 101, for example, transmits information received by itself from another monitoring device 101 to another monitoring device 101 different from the other monitoring device 101 as "transfer". to other monitoring devices 101 .

A monitoring device 101 is a device having a wireless communication function. The monitoring device 101 performs specific low-power radio communication using, for example, a 920 MHz communication band.

The types of the monitoring device 101 include a monitoring parent device 102 having a parent device function and a monitoring child device 103 having a child device function and performing wireless communication with the monitoring parent device 102 . A monitoring parent device 102 and a plurality of monitoring child devices 103 perform multi-hop communication.

When a plurality of monitoring devices 101 are provided, the plurality of monitoring devices 101 serially transmit information via wireless transmission lines, that is, are connected in series via wireless transmission lines. In other words, the communication system 301 does not constitute a transmission line in which a plurality of monitoring devices 101 are arranged in parallel or in a mesh pattern, but constitutes a wireless transmission line in which a plurality of monitoring devices 101 are arranged in series. In this case, the monitoring system T includes one monitoring parent device 102 and one or more monitoring child devices 103 .

The host device 181 is a device that can communicate with the collection device 151 . Host device 181 can communicate with collection device 151, for example, via a mobile phone line.

The collection device 151 receives information transmitted from the monitoring parent device 102 and transfers the received information to the host device 181 . The collection device 151 also receives information transmitted from the host device 181 and transfers the received information to the monitoring parent device 102 .

Hereinafter, the supervisor device 103 side viewed from the host device 181 may be referred to as the "downstream side", and the host device 181 side viewed from the supervisor device 103 may be referred to as the "upstream side". Also, the direction from the host device 181 to the supervisory device 103 may be called the "downward direction", and the direction from the supervisory device 103 to the host device 181 may be called the "upward direction".

The number of monitoring devices 101 included in the monitoring system T is not particularly limited, and is, for example, 50 or more.

The monitoring master device 102 acquires measurement information indicating the measurement result of its own sensor, and transfers the acquired measurement information to the collection device 151 .

Also, the monitoring parent device 102 acquires measurement information from the monitoring child device 103 and transfers the acquired measurement information to the collection device 151 . Also, the monitoring parent device 102 receives setting information and the like from the collection device 151 and transfers the received setting information and the like to the monitoring child device 103 .

The monitoring child device 103 acquires measurement information indicating measurement information of its own sensor, and transfers the acquired measurement information to another monitoring child device 103 or the monitoring parent device 102 on the upstream side.

Further, the monitoring child device 103 acquires measurement information from other monitoring child devices 103 on the downstream side, and transfers the acquired measurement information to the other monitoring child device 103 on the upstream side or the monitoring parent device 102 . Further, the monitor child device 103 receives setting information and the like from another monitor child device 103 on the upstream side or the monitoring parent device 102, and transfers the received setting information and the like to the other monitor child device 103 on the downstream side.

Note that when the received information is addressed to itself, the collecting device 151 and the monitoring device 101 process the information without transferring it.

FIG. 2 is a diagram showing an application example of the communication system according to the embodiment of the present invention.

Referring to FIG. 2, a plurality of monitoring devices 101 are installed at different positions in the power system, for example, at a plurality of positions capable of detecting information necessary for maintenance of the power system. Specifically, for example, a plurality of monitoring devices 101 are installed on a plurality of steel towers 2 provided in an electric power system. The overhead ground wire 3 and the transmission line 4 are installed between adjacent steel towers 2 .

Note that the monitoring device 101 may be installed in all the steel towers 2 in the section to be monitored, or may be installed in some of the steel towers 2 in the section to be monitored.

Specifically, the monitoring device 101 may be installed, for example, every other, every two, or every three towers 2 installed side by side. In the example shown in FIG. 2, the monitoring devices 101 are installed alternately. Whether to install the monitoring device 101 on all the steel towers 2 or on some of the steel towers 2 is determined, for example, based on the installation intervals of the steel towers 2 and the like.

Moreover, the monitoring device 101 is not limited to the steel tower 2, and may be installed around the steel tower 2, or may be installed, for example, on the power transmission line 4, the overhead ground wire 3, or on the ground.

FIG. 3 is a block diagram showing the configuration of the monitoring master device in the communication system according to the embodiment of the invention.

Referring to FIG. 3 , monitoring parent device 102 includes communication unit 104 , battery 106 , control unit 107 , storage unit 108 and sensor 111 .

The communication unit 104 transmits measurement information indicating the amount of charge measured by the sensor 111 of its own monitoring parent device 102 to the collection device 151 . The communication unit 104 and the collection device 151 are, for example, wired and perform serial communication with each other.

Battery 106 supplies power to control unit 107, sensor 111, communication unit 104, storage unit 108, and the like.

The control unit 107 controls operations of the sensor 111, the communication unit 104, and the like. Specifically, for example, control unit 107 periodically performs control to turn on communication unit 104 and turn off communication unit 104 after a predetermined period of time has elapsed.

As an example, the sensor 111 measures the charge amount of the overhead ground wire 3 . Note that the detection target of the sensor 111 is not particularly limited.

Further, when the control unit 107 receives predetermined information indicating the expected lightning strike area and the expected lightning strike period from the host device 181 via the communication unit 104 and the collection device 151, it controls, for example, a switch (not shown). As a result, power supply from the battery 106 to the sensor 111 is started to control the sensor 111 to transition from the OFF state to the ON state.

The control unit 107 receives measurement information indicating the amount of charge measured by the sensor 111 and outputs the received measurement information to the communication unit 104 . When a predetermined time elapses after the sensor 111 is turned on, the control unit 107 stops the power supply from the battery 106 to the sensor 111 by, for example, controlling a switch (not shown) to turn the sensor 111 on. It controls the transition from the ON state to the OFF state.

The storage unit 108 stores a short address or the like, which is assigned to the monitoring parent device 102 and will be described later.

Referring to FIG. 1 again, the collection device 151 transmits the measurement information received from the monitoring parent device 102 to the host device 181 .

The host device 181 receives measurement information from the collection device 151 and performs various calculations based on the received measurement information. For example, the host device 181 receives measurement information indicating the amount of charge from the plurality of monitoring devices 101 via the collection device 151, and the distribution of the amount of charge between the plurality of steel towers 2 based on the amount of charge indicated by each received measurement information. is calculated, and the position of the lightning strike is estimated based on the calculated charge amount distribution.

FIG. 4 is a block diagram showing the configuration of the supervisory device in the communication system according to the embodiment of the invention.

Referring to FIG. 4 , monitor device 103 includes communication unit 105 , battery 106 , control unit 107 , storage unit 108 and sensor 111 .

The communication unit 105 transmits measurement information indicating the charge amount measured by the sensor 111 of its own monitor device 103 to another monitor device 103 or the monitoring parent device 102 on the upstream side. Further, when the communication unit 105 receives the measurement information indicating the charge amount from the monitoring child device 103 located downstream, the communication unit 105 transfers the received measurement information to the other monitoring child device 103 or the monitoring parent device 102 on the upstream side. .

FIG. 5 is a diagram showing an example of address allocation in the communication system according to the embodiment of the invention. A case will be described below where the communication system 301 includes the supervisory device 103_1 and the supervisory device 103_2 which are the supervisory devices 103 . The supervisory device 103_1 and the supervisory device 103_2 are installed in this order from the upstream side.

Referring to FIG. 5, in communication system 301, a first lower layer that is a lower layer in communication between host device 181 and collection device 151 and a lower layer that is a lower layer in communication between collection device 151 and monitoring device 101 2 lower layer.

Specifically, communication using, for example, a mobile phone line is performed between the host device 181 and the collection device 151 . Between the upper device 181 and the collection device 151, a communication protocol for mobile phone lines, such as IP, is used as a first lower layer communication protocol.

On the other hand, for example, serial communication is performed between the collection device 151 and the monitoring parent device 102 . A communication protocol for serial communication is used as a second lower layer communication protocol between the collection device 151 and the monitoring parent device 102 .

Further, between the monitoring parent device 102 and the monitoring child device 103 and between the monitoring child devices 103, for example, specified low-power radio communication using the 920 MHz band communication band according to the IEEE802.15.4 communication standard is performed. The communication protocol for the specified low-power wireless communication is used as the communication protocol of the second lower layer between the monitoring parent device 102 and the monitoring child device 103 and between the monitoring child device 103 .

The upper device 181 holds the first terminal identifiers used in the first lower layer, such as first list information of IP addresses, in a storage unit (not shown).

FIG. 6 is a diagram showing an example of first list information held by a host device in the communication system according to the embodiment of the invention.

Referring to FIG. 6, first list information TL1 indicates the correspondence relationship between the PAN_ID, the IP address of host device 181, and the IP address of collection device 151 for each monitoring system T managed by host device 181. FIG.

In addition, the upper device 181 holds second terminal identifiers used in the second lower layer, for example, second list information of short addresses in a storage unit (not shown).

FIG. 7 is a diagram showing an example of second list information held by a host device in the communication system according to the embodiment of the present invention.

Referring to FIG. 7, the second list information TL2 includes the monitoring system number, the PAN_ID, the short address of the host device 181, the short address of the collection device 151, and the monitoring system number for each monitoring system T managed by the host device 181. The correspondence relationship among the short address and tower number of the monitoring parent device 102, the short address and tower number of the supervisory child device 103_1, and the short address and tower number of the supervisory child device 103_2 is shown.

The monitoring system number and tower number indicate the installation location of the tower. As a result, the user can, for example, input the monitoring system number and the tower number to the host device 181 to specify the monitoring device 101 and the like in the desired tower to the host device 181, and acquire various information. can.

The collection device 151 holds, in a storage unit (not shown), first terminal identifiers used in the first lower layer, such as first list information of IP addresses.

Specifically, for example, the first list information is list information of IP addresses assigned to the host device 181 and the collection device 151 .

FIG. 8 is a diagram showing an example of first list information held by the collection device in the communication system according to the embodiment of the invention. FIG. 8 shows an example of the first list information held by the collection device 151 belonging to the monitoring system T1.

Referring to FIG. 8, first list information SL1 shows the correspondence relationship among PAN_ID, IP address of host device 181, and IP address of collection device 151 in monitoring system T1.

FIG. 9 is a diagram showing an example of first list information held by the collection device in the communication system according to the embodiment of the invention. FIG. 9 shows an example of the first list information held by the collection device 151 belonging to the monitoring system T2.

Referring to FIG. 9, first list information SL1 shows the correspondence relationship between PAN_ID, IP address of host device 181, and IP address of collection device 151 in monitoring system T2.

In addition, the collection device 151 holds second terminal identifiers used in the second lower layer, such as second list information of short addresses, in a storage unit (not shown).

Specifically, for example, the second list information is list information of short addresses assigned to the host device 181 , the collection device 151 , the monitoring parent device 102 and the monitoring child device 103 .

FIG. 10 is a diagram showing an example of second list information held by the collecting device and the monitoring device in the communication system according to the embodiment of the present invention. FIG. 10 shows an example of second list information held by the collection device 151, the monitoring parent device 102, and the monitoring child device 103 belonging to the monitoring system T1.

Referring to FIG. 10, second list information SL2 includes the monitoring system number, PAN_ID, short address of host device 181, short address of collecting device 151, and short address of monitoring parent device 102 of monitoring system T1. and the tower number, the short address and tower number of the supervisor device 103_1, and the short address and tower number of the supervisor device 103_2.

FIG. 11 is a diagram showing an example of second list information held by the collecting device and the monitoring device in the communication system according to the embodiment of the present invention. FIG. 11 shows an example of second list information held by the collection device 151, the monitoring parent device 102, and the monitoring child device 103 belonging to the monitoring system T2.

Referring to FIG. 11, second list information SL2 includes the monitoring system number, PAN_ID, short address of host device 181, short address of collecting device 151, and short address of monitoring parent device 102 of monitoring system T2. and the tower number, the short address and tower number of the supervisor device 103_1, and the short address and tower number of the supervisor device 103_2.

As described above, in the communication system 301, different first terminal identifiers, such as IP addresses, are fixedly assigned to the collection device 151 and the host device 181, respectively.

Different second terminal identifiers, for example, short addresses, are fixedly assigned to the collecting device 151, the monitoring parent device 102, the monitoring child device 103, and the host device 181, respectively.

Different network identifiers such as PAN_ID (Personal Area Network Identification) are fixedly assigned to the monitoring systems T1 and T2, respectively.

In the communication system 301, the monitoring parent device 102, the plurality of monitoring child devices 103, the collection device 151 and the upper device 181 use second terminal identifiers, for example, a source short address and a destination short address as source addresses and destination addresses. send and receive packets in which each is stored.

FIG. 12 is a diagram showing an example of essential parts of a packet in the communication system according to the embodiment of the invention.

Referring to FIG. 12, a packet transmitted between host device 181 and collection device 151 includes a TCP/IP header, a routing header, an application header and an application payload. The TCP/IP header and routing header are used for lower layer communication, and the application header and application payload are used for upper layer communication. Note that the packet may include data other than the contents shown in FIG. 12 .

The host device 181 can recognize the contents of the application header and application payload. On the other hand, the collector 151 cannot recognize the content of the application header and application payload.

Packets transmitted between collection device 151 and monitoring parent device 102 include a serial header, a routing header, an application header and an application payload. The serial header and routing header are used for lower layer communication, and the application header and application payload are used for upper layer communication.

While the collection device 151 and monitoring parent device 102 can recognize the contents of the serial header and routing header, they cannot recognize the contents of the application header and application payload.

A packet transmitted between the monitoring parent device 102 and the monitoring child device 103 is a wireless packet and includes a wireless header, a routing header, an application header and an application payload. The radio header and routing header are used for lower layer communications, and the application header and application payload are used for higher layer communications.

The monitoring parent device 102 and monitoring child device 103 can recognize the contents of the radio header and the routing header, but cannot recognize the contents of the application header and the application payload.

Packets transmitted between supervisory devices 103 are wireless packets and include a wireless header, a routing header, an application header and an application payload. The radio header and routing header correspond to lower layers, and the application header and application payload correspond to higher layers.

The supervisor device 103 can recognize the contents of the radio header and the routing header, but cannot recognize the contents of the application header and the application payload.

FIG. 13 is a diagram showing an example of packets used between a host device and a collection device in the communication system according to the embodiment of the invention. FIG. 13 shows the format of an IP packet.

Referring to FIG. 13, an IP packet includes a TCP/IP header and a routing packet stored in payload.

A TCP/IP header includes, for example, a “destination IP address” and a “source IP address”.

A routing packet includes, for example, a routing header and an application packet contained in a payload.

The routing header includes, for example, "destination PAN_ID", "source PAN_ID", "destination short address" and "source short address".

An application packet includes, for example, an application header and an application payload.

The application payload contains target information such as measurement information. The target information includes, for example, information used for maintenance of power systems such as power transmission facilities. Specifically, when the monitoring device 101 is installed on the steel tower 2 , the target information includes, for example, measurement information indicating the amount of electric charge used for detecting the lightning strike position on the power transmission equipment, and the temperature information used for monitoring the temperature of the power transmission line 4 . , measurement information indicating the inclination of the steel tower 2, or measurement information indicating the depth of snow on the ground.

Further, when the monitoring device 101 is installed on the power transmission line 4, the target information includes, for example, measurement information indicating the amount of electric charge used for detecting the lightning strike position on the power transmission equipment, and the temperature used for monitoring the temperature of the power transmission line 4. measurement information, or measurement information indicating inclination due to slackness of the power transmission line 4 or the like.

Further, when the monitoring device 101 is installed in the overhead ground wire 3, the target information is, for example, measurement information indicating the amount of electric charge used for detecting the lightning strike position to the power transmission equipment, and the temperature monitoring of the overhead ground wire 3. It includes measurement information indicating temperature or measurement information indicating inclination due to slackness of the overhead ground wire 3 or the like.

Also, when the monitoring device 101 is installed on the ground around the steel tower 2, the target information is, for example, measurement information indicating the inclination of the ground, measurement information indicating vibration of the ground, or depth of snow on the ground. Includes measurement information, etc.

The detection target of the sensor 111 in the monitoring device 101 and the type of the sensor 111 are appropriately set according to the type of target information.

FIG. 14 is a diagram showing an example of packets used between the collection device and the wireless master device in the communication system according to the embodiment of the present invention. FIG. 14 shows the format of a serial packet transmitted by serial communication.

Referring to FIG. 14, the serial packet includes a serial header and a routing packet stored in payload.

A serial header is a header used for serial communication. The routing packet has the same content as the routing packet shown in FIG.

FIG. 15 is a diagram showing an example of radio packets used between monitoring devices in the communication system according to the embodiment of the present invention. FIG. 15 shows the format of a radio packet transmitted by 920 MHz specified low-power radio communication.

Referring to FIG. 15, the radio packet includes a radio header and a routing packet stored in payload.

A radio header is a header used for specific low-power radio communication. The routing packet differs from the routing packet shown in FIG. 13 in that a sequence number is added to the routing header.

The sequence number is basically different for each wireless packet. Note that when the monitoring device 101 retransmits a wireless packet, the same sequence number is assigned to the wireless packet before and after the retransmission.

[Flow of operation]
Each device in the communication system 301 includes a computer including a memory, and an arithmetic processing unit such as a CPU in the computer reads out from the memory a program including part or all of each step in the following sequence diagrams or flowcharts. Execute. Programs for these multiple devices can each be installed from the outside. Programs for these devices are stored in recording media and distributed.

FIG. 16 is a diagram showing an example of an information transmission sequence in the communication system according to the embodiment of the present invention.

FIG. 16 shows eight transmission examples 1 to 8 of packets in the host device 181 and the monitoring system T1, that is, between the host device 181, the collection device 151, the supervisory parent device 102, and the two supervisory slave devices 103_1 and 103_2. It shows an example of sequential execution.

In transmission example 1 in which information is transmitted in the downstream direction, the host device 181 transmits an IP packet including setting information of the collection device 151 to the collection device 151 .

This IP packet contains "0x0001" as the destination PAN_ID, "192.168.1.3" as the destination IP address, "192.168.1.2" as the source IP address, and "0xFFFD" is included as the destination short address, and "0xFFFE" is included as the source short address. This IP packet does not contain the source PAN_ID.

Next, the collection device 151 receives IP packets from the host device 181 and processes them.

In transmission example 2 in which information is transmitted in the upstream direction, the collection device 151 transmits IP packets including measurement information and the like to the host device 181 .

This IP packet contains "0x0001" as the source PAN_ID, "192.168.1.2" as the destination IP address, "192.168.1.3" as the source IP address, and the "0xFFFE" is included as the destination short address, and "0xFFFD" is included as the source short address. This IP packet does not contain the destination PAN_ID.

Next, the host device 181 receives IP packets from the collection device 151 and processes them.

In transmission example 3 in which information is transmitted in the downstream direction, the host device 181 transmits an IP packet including setting information of the monitoring parent device 102 and the like to the collection device 151 .

This IP packet contains "0x0001" as the destination PAN_ID, "192.168.1.3" as the destination IP address, "192.168.1.2" as the source IP address, and "0x0000" is included as the destination short address, and "0xFFFE" is included as the source short address. This IP packet does not contain the source PAN_ID.

Next, when the collection device 151 receives an IP packet from the host device 181, the collection device 151 deletes the TCP/IP header of the received IP packet, adds a serial header to create a serial packet, and monitors the created serial packet. Send to parent device 102 .

This serial packet contains "0x0001" as the destination PAN_ID, "0x0000" as the destination short address, and "0xFFFE" as the source short address. This serial packet does not contain the source PAN_ID.

Monitoring parent device 102 then receives and processes the serial packet from collection device 151 .

In transmission example 4, in which information is transmitted in the upstream direction, the monitoring master device 102 transmits a serial packet including measurement information and the like to the collection device 151 .

This serial packet includes "0x0001" as the source PAN_ID, "0xFFFE" as the destination short address, and "0x0000" as the source short address. This serial packet does not contain the destination PAN_ID.

Next, when the collection device 151 receives a serial packet from the monitoring parent device 102, the collection device 151 deletes the serial header of the received serial packet, adds a TCP/IP header to create an IP packet, and converts the created IP packet to It is transmitted to the host device 181 .

This IP packet contains "0x0001" as the source PAN_ID, "0xFFFE" as the destination short address, and "0x0000" as the source short address. This IP packet does not contain the destination PAN_ID.

Next, the host device 181 receives IP packets from the collection device 151 and processes them.

In transmission example 5 in which information is transmitted in the downlink direction, the host device 181 transmits an IP packet including setting information of the supervisory child device 103_2 to the collection device 151 .

This IP packet contains "0x0001" as the destination PAN_ID, "192.168.1.3" as the destination IP address, "192.168.1.2" as the source IP address, and "0x0002" is included as the destination short address, and "0xFFFE" is included as the source short address. This IP packet does not contain the source PAN_ID.

Next, when the collection device 151 receives an IP packet from the host device 181, the collection device 151 deletes the TCP/IP header of the received IP packet, adds a serial header to create a serial packet, and monitors the created serial packet. Send to parent device 102 .

This serial packet includes "0x0001" as the destination PAN_ID, "0x0002" as the destination short address, and "0xFFFE" as the source short address. This serial packet does not contain the source PAN_ID.

Next, when the monitoring parent device 102 receives a serial packet from the collecting device 151, it deletes the serial header of the received serial packet, adds a wireless header to create a wireless packet, and sends the created wireless packet to the monitoring device 102. Send to the device 103_1.

This wireless packet includes "0x0001" as the destination PAN_ID, "0x0001" as the destination wireless address, "0x0000" as the source wireless address, "0x0002" as the destination short address, and "0x0002" as the destination short address. It contains "0xFFFE" as a short address. This radio packet does not contain the source PAN_ID.

Next, when the monitoring child device 103_1 receives a wireless packet from the monitoring parent device 102, it deletes the wireless header of the received wireless packet and adds a new wireless header to create a new wireless packet. A wireless packet is transmitted to the supervisory slave device 103_2.

This wireless packet includes “0x0001” as the destination PAN_ID, “0x0002” as the destination wireless address, “0x0001” as the source wireless address, “0x0002” as the destination short address, and “0x0002” as the destination short address. It contains "0xFFFE" as a short address. This radio packet does not contain the source PAN_ID.

Next, the supervisory device 103_2 receives and processes the wireless packet from the supervisory device 103_1.

In the transmission example 6 in which information is transmitted in the upstream direction, the supervisory device 103_2 transmits a wireless packet including measurement information and the like to the supervisory device 103_1.

This wireless packet includes “0x0001” as the source PAN_ID, “0x0001” as the destination wireless address, “0x0002” as the source wireless address, “0xFFFE” as the destination short address, and “0xFFFE” as the destination short address. It contains "0x0002" as a short address. This radio packet does not contain the destination PAN_ID.

Next, when the supervisory device 103_1 receives a wireless packet from the supervisory device 103_2, it deletes the wireless header of the received wireless packet and adds a new wireless header to create a new wireless packet. Send the wireless packet to the monitoring parent device 102 .

This wireless packet includes “0x0001” as the source PAN_ID, “0x0000” as the destination wireless address, “0x0001” as the source wireless address, “0xFFFE” as the destination short address, and “0xFFFE” as the destination short address. It contains "0x0002" as a short address. This radio packet does not contain the destination PAN_ID.

Next, when the monitoring parent device 102 receives a wireless packet from the monitoring child device 103_1, it deletes the wireless header of the received wireless packet, adds a serial header to create a serial packet, and collects the created serial packet. Send to device 151 .

This serial packet includes "0x0001" as the source PAN_ID, "0xFFFE" as the destination short address, and "0x0002" as the source short address. This serial packet does not contain the destination PAN_ID.

Next, when the collection device 151 receives a serial packet from the monitoring parent device 102, the collection device 151 deletes the serial header of the received serial packet, adds a TCP/IP header to create an IP packet, and converts the created IP packet to It is transmitted to the host device 181 .

This IP packet contains "0x0001" as the source PAN_ID, "192.168.1.2" as the destination IP address, "192.168.1.3" as the source IP address, and the "0xFFFE" is included as the destination short address, and "0x0002" is included as the source short address. This IP packet does not contain the destination PAN_ID.

Next, the host device 181 receives IP packets from the collection device 151 and processes them.

In transmission example 7 in which information is transmitted in the downward direction, the monitoring parent device 102 transmits a wireless packet including information for setting the monitoring device 103_2 to the monitoring device 103_1.

This wireless packet includes "0x0001" as the destination PAN_ID, "0x0001" as the source PAN_ID, "0x0001" as the destination wireless address, "0x0000" as the source wireless address, and "0x0000" as the source wireless address. It contains "0x0002" as an address and "0x0000" as a source short address.

Next, when the monitoring child device 103_1 receives a wireless packet from the monitoring parent device 102, it deletes the wireless header of the received wireless packet and adds a new wireless header to create a new wireless packet. A wireless packet is transmitted to the supervisory slave device 103_2.

This wireless packet includes “0x0001” as the destination PAN_ID, “0x0001” as the source PAN_ID, “0x0002” as the destination wireless address, “0x0001” as the source wireless address, and “0x0001” as the source short address. It contains "0x0002" as an address and "0x0000" as a source short address.

Next, the supervisory device 103_2 receives and processes the wireless packet from the supervisory device 103_1.

In transmission example 8 in which information is transmitted in the uplink direction, the supervisory device 103_2 transmits a wireless packet including information such as measurement information to the supervisory device 103_1.

This wireless packet includes “0x0001” as the destination PAN_ID, “0x0001” as the source PAN_ID, “0x0001” as the destination wireless address, “0x0002” as the source wireless address, and “0x0002” as the source wireless address. It contains "0x0000" as an address and "0x0002" as a source short address.

Next, when the supervisory device 103_1 receives a wireless packet from the supervisory device 103_2, it deletes the wireless header of the received wireless packet and adds a new wireless header to create a new wireless packet. Send the wireless packet to the monitoring parent device 102 .

This wireless packet includes "0x0001" as the destination PAN_ID, "0x0001" as the source PAN_ID, "0x0000" as the destination wireless address, "0x0001" as the source wireless address, and "0x0001" as the source wireless address. It contains "0x0000" as an address and "0x0002" as a source short address.

Next, the monitoring parent device 102 receives and processes the wireless packet from the monitoring child device 103_1.

In the communication system 301, packets transmitted between each device contain PAN_ID. As a result, for example, even if a monitoring device 101 having an incorrect PAN_ID is installed during construction work to install the monitoring device 101 on the steel tower 2, for example, the host device 181 can recognize the error. Note that the communication system 301 may have a configuration in which packets transmitted between devices do not include the PAN_ID.

Processing performed when wireless packet transfer fails between the monitoring devices 101 will be described below.

FIG. 17 is a diagram showing an example of a wireless packet transfer method between monitoring devices in the communication system according to the embodiment of the present invention. Here, an example in which five monitoring devices 101, that is, a monitoring device 101_0, a monitoring device 101_1, a monitoring device 101_2, a monitoring device 101_3, and a monitoring device 101_4 are arranged in series in this order will be described.

Note that the direction from the monitoring device 101_0 to the monitoring device 101_4 may be the upward direction or the downward direction.

The monitoring device 101 shown in FIG. 17 is the monitoring parent device 102 shown in FIG. 3 or the monitoring child device 103 shown in FIG. For example, the monitoring device 101_0 may be the monitoring parent device 102, the monitoring devices 101_1 to 101_4 may be the monitoring child devices 103, the monitoring devices 101_0 to 101_4 may be the monitoring child devices 103, or The device 101_4 may be the monitoring parent device 102 and the monitoring devices 101_0 to 101_3 may be the monitoring child devices 103 .

Hereinafter, each of communication section 104 and communication section 105 is also referred to as communication section 50 .

Referring to FIGS. 3 and 4 again, communication unit 50 changes the destination short address when retransmitting a wireless packet. Specifically, the communication unit 50 changes the destination short address in the routing header of the wireless packet to the short address of the monitoring device 101 one or more ahead of the monitoring device 101 having the destination short address.

Further, when the own monitoring device 101 is the transmission source of the wireless packet, the communication unit 50 stores the transmission destination short address and the transmission source short address in the wireless header, and stores the transmission destination short address and the transmission source short address in the routing header. A wireless packet is created in which the source short address and the sequence number are stored, and the wireless packet is transmitted.

Also, upon receiving a wireless packet from another monitoring device 101 , the communication unit 50 stores the received wireless packet in the storage unit 108 .

Referring to FIG. 17 again, each of the five monitoring devices 101 is pre-assigned a terminal identifier, specifically a short address. Specifically, the short addresses assigned to the monitoring device 101_0, the monitoring device 101_1, the monitoring device 101_2, the monitoring device 101_3, and the monitoring device 101_4 are, for example, 0x0000, 0x0001, 0x0002, 0x0003, and 0x0004, respectively.

The communication unit 50 in each monitoring device 101 can transfer wireless packets to another monitoring device 101 having a first short address registered in advance in itself, for example, in each of the uplink and downlink directions. Specifically, the first short address is the short address of another monitoring device 101 in the subsequent stage, for example, the short address of the monitoring device 101 in the next stage.

Specifically, for example, the communication unit 50 in each monitoring device 101 transfers the wireless packet to the next monitoring device 101, that is, the neighboring monitoring device 101 .

For example, the monitoring device 101_0 whose short address is 0x0000 transfers the wireless packet to the monitoring device 101_1 whose short address is 0x0001. The monitoring device 101_1 receives the wireless packet from the monitoring device 101_0 and transfers the wireless packet to the monitoring device 101_2 whose short address is 0x0002.

More specifically, the communication unit 50 in the monitoring device 101_1 deletes the wireless header of the wireless packet received from the monitoring device 101_0. The communication unit 50 in the monitoring device 101_1 refers to the second list information SL2 shown in FIG. 10 or 11, adds a wireless header whose destination short address is 0x0002, and creates a new wireless packet. Then, the communication unit 50 in the monitoring device 101_1 transfers the created wireless packet to the monitoring device 101_2.

The communication unit 50 in each monitoring device 101 has a second short address pre-stored therein when the transfer of information to the other monitoring device 101 fails in each of the upstream and downstream directions, for example. information is transferred to another monitoring device 101 in the subsequent stage having the second short address, for example.

The second short address is, for example, the short address of the next monitoring device 101 . That is, for example, in each of the upstream direction and the downstream direction, the second short address held by monitoring device 101 is assigned to monitoring device 101 positioned after monitoring device 101 to which the first short address is assigned. It is assigned to the monitoring device 101 located in the next stage. In other words, the monitoring device 101 skips the transfer destination of the wireless packet when the transfer of information to another monitoring device 101 fails.

Specifically, for example, when the communication unit 50 in each monitoring device 101 fails to transfer the wireless packet to the monitoring device 101 in the next stage, it transfers the wireless packet to the monitoring device 101 in the succeeding stage.

Note that the second short address held by the monitoring device 101 in each of the upstream direction and the downstream direction may be the monitoring device 101 located next to the monitoring device 101 to which the first short address is assigned. However, it may be the monitoring device 101 located in the next stage or later.

In addition, the communication unit 50 in each monitoring device 101, for example, in each of the upstream direction and the downstream direction, when the transfer of the information to the other monitoring device 101 to be skipped fails, the third short circuit stored in advance in itself. The information is transferred to another monitoring device 101 having the address, for example, to a further monitoring device 101 in the next stage or later.

The third short address is, for example, the short address of the next monitoring device 101 in the next stage. That is, in each of the upstream and downstream directions, for example, the third short address held by monitoring device 101 is assigned to monitoring device 101 positioned next to monitoring device 101 to which the second short address is assigned. there is In other words, the monitoring device 101 further skips the transfer destination of the wireless packet when the information transfer to the other skip destination monitoring device 101 fails.

Specifically, for example, when the communication unit 50 in each monitoring device 101 fails to transfer the wireless packet to the next monitoring device 101, the communication unit 50 transfers the wireless packet to the next next monitoring device 101.

In FIG. 17, the communication unit 50 in the monitoring device 101_2 transfers the wireless packet to the monitoring device 101_4 when transfer of the packet to the monitoring device 101_3 fails.

FIG. 18 is a diagram showing an example of a skip setting table held by each monitoring device in the communication system according to the embodiment of the invention.

Referring to FIG. 18, skip setting table Tbs includes information related to skip operations. Information related to the skip operation is, for example, the allowable waiting time Tmax, the allowable number of retransmissions Sdmax, the allowable number of skips Skmax, and the number of initial skips. The storage unit 108 in each monitoring device 101 stores the skip setting table Tbs.

The permissible waiting time Tmax is the maximum time that can be waited until a wireless packet indicating ACK (Acknowledgement) is received from the transfer destination monitoring device 101 after the wireless packet is transferred. The communication unit 50 in the monitoring device 101 of the transmission source determines that the transfer of the wireless packet has failed when the allowable waiting time Tmax has elapsed. Hereinafter, a radio packet indicating ACK may be simply referred to as "ACK".

The allowable number of retransmissions Sdmax is the maximum number of times transfer can be retried when the communication unit 50 in the monitoring device 101 determines that transfer has failed.

When the communication unit 50 in the monitoring device 101 of the transmission source determines that the transfer of the wireless packet has failed, the transfer is retried with the allowable number of retransmissions Sdmax as the upper limit, that is, the wireless packet is retransmitted.

The allowable number of skips Skmax is the maximum number that the monitoring device 101 can be skipped. The allowable number of skips Skmax depends on the number of monitoring devices 101 from the monitoring device 101 to the terminal monitoring device 101 in the wireless packet transmission direction.

The initial skip number Sk1 is the initial value of the skip number. The initial skip number Sk1 is set to 0, for example.

Referring to FIG. 17 again, for example, it is assumed that the direction from the monitoring device 101_4 to the monitoring device 101_0 is the upward direction and the direction from the monitoring device 101_0 to the monitoring device 101_4 is the downward direction. Further, for example, it is assumed that the monitoring devices 101_1 to 101_4 are the monitoring slave devices 103 and the monitoring device 101_0 is the monitoring parent device 102 .

In the communication system 301, each monitoring device 101 separately holds one or a plurality of short addresses for uplink and downlink.

The storage unit 108 of each monitoring device 101 has an address area for separately holding one or more short addresses for upstream and downstream directions, and a flag area for indicating the validity of the short address in the address area. ing.

Specifically, for example, the monitoring device 101_4 located at the starting point in the upstream direction holds a first short address, a second short address and a third short address for the upstream direction. Also, the monitoring device 101_4 located at the downstream end point does not hold the first short address, the second short address, and the third short address for the downstream direction.

The address area in the storage unit 108 of the monitoring device 101_4 includes three stored areas for respectively storing a first short address, a second short address, and a third short address for the upstream direction, and the short address is added. and a plurality of unstored areas in which data can be stored.

The flag area in the storage unit 108 of the monitoring device 101_4 has three areas respectively corresponding to the three stored areas and a plurality of areas corresponding to the plurality of non-stored areas. A flag "1" indicating that the corresponding short address is valid is stored in the above three areas. On the other hand, the plurality of areas store a flag "0" indicating that the corresponding short address is not stored or that the corresponding short address is invalid.

Also, the monitoring device 101_3 positioned next to the starting point in the upstream direction holds the first short address, the second short address and the third short address for the upstream direction. Also, the monitoring device 101_3 positioned before the end point in the downlink direction holds the first short address for the downlink direction, and does not hold the second short address and the third short address for the downlink direction.

The address areas in the storage unit 108 of the monitoring device 101_3 are four addresses each storing a first short address, a second short address and a third short address for the upstream direction, and a first short address for the downstream direction. It has a stored area and a plurality of unstored areas in which short addresses can be added and stored.

The flag area in the storage unit 108 of the monitoring device 101_3 has four areas respectively corresponding to the above-described four stored areas, and a plurality of areas respectively corresponding to the above-described plurality of non-stored areas. A flag "1" indicating that the corresponding short address is valid is stored in the above four areas. On the other hand, the plurality of areas store a flag "0" indicating that the corresponding short address is not stored or that the corresponding short address is invalid.

In addition, the monitoring device 101_2 located two steps before the end point in the upstream direction holds the first short address and the second short address for the upward direction, and holds the third short address for the upward direction. do not have. In addition, the monitoring device 101_2 located two steps before the downstream end point holds the first short address and the second short address for the downstream direction, and holds the third short address for the downstream direction. do not have.

The address areas in the storage unit 108 of the monitoring device 101_2 are four addresses each storing a first short address and a second short address for the upstream direction and a first short address and a second short address for the downstream direction. It has a stored area and a plurality of unstored areas in which short addresses can be added and stored.

The flag area in the storage unit 108 of the monitoring device 101_2 has four areas respectively corresponding to the above-described four stored areas, and a plurality of areas respectively corresponding to the above-described plurality of non-stored areas. A flag "1" indicating that the corresponding short address is valid is stored in the above four areas. On the other hand, the plurality of areas store a flag "0" indicating that the corresponding short address is not stored or that the corresponding short address is invalid.

Also, the monitoring device 101_1 positioned before the end point in the upstream direction holds the first short address for the upward direction, and does not hold the second short address and the third short address for the upward direction. Also, the monitoring device 101_1 positioned next to the start point in the downlink direction holds the first short address, the second short address, and the third short address for the downlink direction.

The address area in the storage unit 108 of the monitoring device 101_1 includes four addresses each storing a first short address for the upstream direction and a first short address, a second short address and a third short address for the downstream direction. It has a stored area and a plurality of unstored areas in which short addresses can be added and stored.

The flag area in the storage unit 108 of the monitoring device 101_1 has four areas respectively corresponding to the above-mentioned four stored areas, and a plurality of areas respectively corresponding to the above-mentioned plurality of non-stored areas. A flag "1" indicating that the corresponding short address is valid is stored in the above four areas. On the other hand, the plurality of areas store a flag "0" indicating that the corresponding short address is not stored or that the corresponding short address is invalid.

Also, the monitoring device 101_0 located at the end point in the upstream direction does not hold the first short address, the second short address, and the third short address for the upstream direction. Also, the monitoring device 101_0 located at the starting point of the downlink holds the first short address, the second short address and the third short address for the downlink.

The address area in the storage unit 108 of the monitoring device 101_0 includes three stored areas for respectively storing a first short address, a second short address, and a third short address for the downstream direction, and a short address is added. and a plurality of unstored areas in which data can be stored.

The flag area in the storage unit 108 of the monitoring device 101_0 has three areas respectively corresponding to the above-described three stored areas, and a plurality of areas respectively corresponding to the above-described plurality of non-stored areas. A flag "1" indicating that the corresponding short address is valid is stored in the above three areas. On the other hand, the plurality of areas store a flag "0" indicating that the corresponding short address is not stored or that the corresponding short address is invalid.

Also, in each of the upstream direction and the downstream direction, the first short addresses of the respective monitoring devices 101 holding the first short addresses are exclusive, that is, they are different from each other.

Also, in each of the upstream direction and the downstream direction, the second short addresses of each monitoring device 101 holding the second short addresses are exclusive, that is, they are different from each other.

Also, in each of the upstream direction and the downstream direction, the third short address of each monitoring device 101 holding the third short address is exclusive, that is, different from each other.

FIG. 19 is a diagram showing an example of a skip information table held by each monitoring device in the communication system according to the embodiment of the invention. FIG. 19 shows an example of the skip information table held by the monitoring device 101_2.

Referring to FIG. 19, skip information table Tbsk shows the correspondence between the number of skips and the short addresses of other monitoring devices 101 in each of the uplink direction and the downlink direction. For example, a skip number of 0 corresponds to the short address of the adjacent monitoring device 101, that is, the next monitoring device 101, and a skip number of 1 corresponds to the short address of the monitoring device 101 that is two adjacent, that is, the following monitoring device 101. are doing. The storage unit 108 in each monitoring device 101 stores the skip information table Tbsk.

FIG. 20 is a diagram showing an example of a sequence in which the monitoring device in the communication system according to the embodiment of the present invention skips transfer destinations of wireless packets.

Referring to FIG. 20, first, monitoring device 101_0 transfers a wireless packet to monitoring device 101_1 (step S101).

Next, when the monitoring device 101_1 receives the wireless packet from the monitoring device 101_0, it transmits ACK to the monitoring device 101_0 (step S103).

Next, the monitoring device 101_1 transfers the wireless packet to the monitoring device 101_2 (step S105).

Next, when the monitoring device 101_2 receives the wireless packet from the monitoring device 101_1, it transmits ACK to the monitoring device 101_1 (step S107).

Next, the monitoring device 101_2 transfers the wireless packet to the monitoring device 101_3 (step S109).

Next, when the wireless packet transfer fails, the monitoring device 101_2 retransmits the wireless packet to the monitoring device 101_3 (step S111).

Next, when the wireless packet transfer fails again, the monitoring device 101_2 stops transferring packets to the monitoring device 101_3 and changes the transfer destination of the wireless packets to the monitoring device 101_4. That is, the monitoring device 101_2 skips one wireless packet transfer destination (step S113).

Next, the monitoring device 101_2 transfers the wireless packet to the monitoring device 101_4 (step S114).

FIG. 21 is a flow chart defining an example of an operation procedure when the monitoring device in the communication system according to the embodiment of the present invention transfers wireless packets. Here, as an example of the monitoring device 101, the operation when the monitoring device 101_2 in FIG. 20 uses the skip information table Tbsk shown in FIG. 19 will be described.

Referring to FIG. 21, first, communication unit 50 in monitoring device 101_2 transfers a wireless packet to monitoring device 101 in the next stage. Specifically, the communication unit 50 receives a wireless packet containing the short address of the monitoring device 101_0 as a transmission source and a sequence number from the monitoring device 101_1, and transfers the wireless packet to the next-stage monitoring device 101_3 in the downlink direction. (step S201).

Next, the communication unit 50 confirms whether or not ACK has been received from the monitoring device 101_3 (step S203).

When receiving ACK from the monitoring device 101_3 (YES in step S203), the communication unit 50 ends the wireless packet transfer process.

On the other hand, if ACK has not been received from the monitoring device 101_3 (NO in step S203), the communication unit 50 confirms whether or not the allowable waiting time Tmax has elapsed after transferring the wireless packet (step S205).

If the allowable waiting time Tmax has not elapsed since the wireless packet was transferred (NO in step S205), the communication unit 50 waits until an ACK is received from the monitoring device 101_3 (step S203).

On the other hand, if the permissible waiting time Tmax has elapsed since the wireless packet was transferred (YES in step S205), the communication unit 50 determines whether the number of retransmissions of the wireless packet, that is, the number of transfer retries is equal to or less than the permissible number of retransmissions Sdmax. Check whether Note that the allowable number of retransmissions Sdmax is, for example, 1 (step S207).

When the number of retransmissions of the wireless packet is equal to or less than the allowable number of retransmissions Sdmax (YES in step S207), the communication unit 50 retransmits the wireless packet (step S201).

On the other hand, when the number of retransmissions of the wireless packet exceeds the allowable number of retransmissions Sdmax (NO in step S207), the communication unit 50 checks whether the skip number is equal to or less than the allowable skip number Skmax (step S209).

If the number of skips exceeds the allowable number of skips Skmax (NO in step S209), the communication unit 50 stops the wireless packet transfer process.

On the other hand, when the number of skips is equal to or less than the allowable number of skips Skmax (YES in step S209), the communication unit 50 updates the number of skips by adding 1 to the current number of skips (step S211).

Next, the communication unit 50 changes the transfer destination of the wireless packet. Specifically, the communication unit 50 refers to the skip information table Tbsk and changes the destination short address in the routing header of the wireless packet to a short address corresponding to the skip count after updating, thereby making the current transfer The monitoring device 101 one ahead ahead is set as a new transfer destination (step S213).

Note that here, the operation of the communication unit 50 referring to the skip information table Tbsk and skipping the transfer destination of the wireless packet in the downlink transfer has been described. The same applies to the operation of skipping the transfer destination of the wireless packet by referring to the information table Tbsk.

Further, the communication unit 50 may reset the skip count to the initial value of 0 after a predetermined time has passed since the radio packet was transmitted, or may not reset the skip count to the initial value of 0.

Processing when the monitoring device 101 receives wireless packets with the same content multiple times will be described below.

FIG. 22 is a diagram showing an example of processing when the monitoring device in the communication system according to the embodiment of the present invention receives wireless packets with the same content multiple times. In the example shown in FIG. 22, three monitoring devices 101_0, 101_1 and 101_2 are representatively shown.

Referring to FIG. 22, first, communication unit 50 in monitoring device 101_0 transfers a wireless packet to monitoring device 101_1 (step S401).

Next, upon receiving the wireless packet from the monitoring device 101_0, the communication unit 50 in the monitoring device 101_1 transmits ACK to the monitoring device 101_0 (step S403).

Next, the communication unit 50 in the monitoring device 101_1 transfers the wireless packet to the monitoring device 101_2 (step S405).

Next, upon receiving the wireless packet from the monitoring device 101_1, the communication unit 50 in the monitoring device 101_2 transmits ACK to the monitoring device 101_1 (step S407).

Next, if the communication unit 50 in the monitoring device 101_0 cannot receive an ACK within the allowable waiting time Tmax after transferring the wireless packet to the monitoring device 101_1, the communication unit 50 resends the wireless packet to the monitoring device 101_1 (step S409). .

Next, upon receiving the wireless packet from the monitoring device 101_0, the communication unit 50 in the monitoring device 101_1 transmits ACK to the monitoring device 101_0 (step S411).

Next, if the communication unit 50 in the monitoring device 101_0 cannot receive an ACK within the allowable waiting time Tmax after transferring the wireless packet to the monitoring device 101_1, the communication unit 50 changes the transfer destination of the wireless packet. One transfer destination is skipped (step S413).

Next, the communication unit 50 in the monitoring device 101_0 transfers the wireless packet to the monitoring device 101_2 (step S415).

Next, upon receiving the wireless packet from the monitoring device 101_0, the communication unit 50 in the monitoring device 101_2 transmits ACK to the monitoring device 101_0 (step S417).

Next, the communication unit 50 in the monitoring device 101_2 discards the wireless packet received from the monitoring device 101_0. Specifically, when the short address and sequence number included in the newly received wireless packet overlap with the short address and sequence number included in the already received wireless packet, the monitoring device 101_2 detects that the newly received wireless packet is discarded (step S419).

FIG. 23 is a diagram showing an example of a reception history table held by each monitoring device in the communication system according to the embodiment of the invention.

Referring to FIG. 23, reception history table Tbh1 includes information on the reception history of wireless packets. The information of the radio packet reception history includes, for example, the source short address, the sequence number, and the number of receptions of duplicate packets. Storage unit 108 in each monitoring device 101 stores reception history table Tbh1.

The number of receptions of duplicate packets is the number of times the monitoring device 101 receives wireless packets having duplicate source short addresses and duplicate sequence numbers.

FIG. 24 is a diagram showing a discard condition table held by each monitoring device in the communication system according to the embodiment of the invention.

Referring to FIG. 24, discard condition table Tbh2 includes allowable reception count Rmax and update time T2max. The storage unit 108 in each monitoring device 101 stores the discard condition table Tbh2.

FIG. 25 is a flow chart showing an example of an operation procedure when the monitoring device in the communication system according to the embodiment of the present invention receives wireless packets. FIG. 25 shows the operation of the monitoring device 101_2 in FIG.

Referring to FIG. 25, first, communication unit 50 in monitoring device 101_2 waits until a wireless packet is received from another monitoring device 101_1 (NO in step S301).

Next, when receiving a wireless packet from another monitoring device 101_1 (YES in step S301), the communication unit 50 determines whether or not the same wireless packet was received before the received wireless packet. It is checked whether it is the first wireless packet (step S303).

Next, when the received wireless packet is the first wireless packet (YES in step S303), the communication unit 50 starts measuring the elapsed time after receiving the wireless packet (step S305), An ACK is transmitted to the monitoring device 101_1 (step S307).

On the other hand, if the received wireless packet is not the first wireless packet (NO in step S303), the communication unit 50 transmits ACK to the other monitoring device 101 that is the transfer source. For example, when receiving a wireless packet from the monitoring device 101_1, the communication unit 50 transmits ACK to the monitoring device 101_1 (step S307).

Next, communication unit 50 saves the source address and sequence number of the received wireless packet in storage unit 108 . For example, monitoring device 101_2 stores source short address 0x0000 and sequence number 001 of the received wireless packet in reception history table Tbh1 in storage unit 108 (step S309).

Next, the communication unit 50 determines whether or not the elapsed time from the reception of the first wireless packet is equal to or less than the update time T2max (step S311).

When the elapsed time exceeds the update time T2max (NO in step S311), the communication unit 50 deletes the source short address and sequence number corresponding to the received wireless packet from the reception history table Tbh1 (step S313).

On the other hand, if the elapsed time is equal to or less than the update time T2max (YES in step S311), the communication unit 50 determines that the number of receptions of duplicate packets, which are wireless packets with duplicate source short addresses and sequence numbers, is the allowable number of receptions Rmax. It is checked whether or not the above is satisfied (step S315).

If the number of receptions of duplicate packets is less than the allowable number of receptions Rmax (NO in step S315), the communication unit 50 waits until a new wireless packet is received (step S301).

On the other hand, when the number of receptions of duplicate packets is equal to or greater than the allowable number of receptions Rmax (YES in step S315), communication unit 50 deletes the duplicate packets from storage unit 108 (step S317).

In the communication system according to the embodiment of the present invention, monitoring device 101 makes the short address and sequence number included in the newly received wireless packet match the short address and sequence number included in the already received wireless packet, respectively. In the case of duplication, the newly received wireless packet is discarded, but the present invention is not limited to this. Even if the short address and sequence number included in the newly received wireless packet overlap with the short address and sequence number included in the already received wireless packet, the monitoring device 101 receives the newly received wireless packet. It may be configured not to be discarded.

Also, in the communication system according to the embodiment of the present invention, the monitoring device 101 is configured to include the sensor 111, but the present invention is not limited to this. A configuration in which the sensor 111 is provided outside the monitoring device 101 may be employed.

In this case, the sensor 111 transmits information indicating the measurement result to the monitoring device 101 by wired communication or wireless communication.

Further, in the communication system according to the embodiment of the present invention, some monitoring devices 101 among the plurality of monitoring devices 101 may be configured to include the sensor 111 .

For example, some monitoring devices 101 among the plurality of monitoring devices 101 may have sensors 111 and other monitoring devices 101 may not have sensors 111 . In this case, the sensor 111 may be provided outside the monitoring device 101 that does not include the sensor 111 , and the sensor 111 may transmit measurement information indicating the measurement result to the monitoring device 101 .

Also, the monitoring device 101 without the sensor 111 may be configured to transfer information from another monitoring device 101 to another monitoring device 101 without being a source of information.

Further, even in a configuration in which either one of uplink wireless packet transfer and downlink wireless packet transfer is performed between a plurality of monitoring devices 101 in the communication system according to the embodiment of the present invention, good.

Also, in the communication system according to the embodiment of the present invention, each monitoring device 101 is configured to separately hold one or more short addresses for the uplink and downlink directions, but the present invention is not limited to this. At least some of the monitoring devices 101 may store one or more short addresses only for the upstream direction, or at least some of the monitoring devices 101 may store one or more short addresses only for the downstream direction. It may be configured to hold.

If the monitoring device 101 is configured to hold one or more short addresses only for the upstream direction, the following configuration may be used. That is, for example, when the monitoring device 101 receives a packet from another monitoring device 101 on the downstream side, the monitoring device 101 stores the source short address included in the received packet in the storage unit 108 . When the monitoring device 101 transmits a packet in the downstream direction, the monitoring device 101 generates a packet having the saved source short address as the destination short address.

Further, when the monitoring device 101 is configured to hold one or more short addresses only for the downlink, the following configuration may be used. That is, for example, when the monitoring device 101 receives a packet from another monitoring device 101 on the upstream side, the monitoring device 101 stores the source short address included in the received packet in the storage unit 108 . When the monitoring device 101 transmits a packet in the upstream direction, the monitoring device 101 generates a packet having the saved source short address as the destination short address.

By the way, there is a demand for a technique that surpasses the technique described in Patent Literature 1 and is capable of realizing stable operation.

On the other hand, a communication system 301 according to an embodiment of the present invention is a communication system that is used in a power system and has a plurality of monitoring devices 101 . A different short address is fixedly assigned to each of the plurality of monitoring devices 101 . A plurality of monitoring devices 101 can transfer information to another monitoring device 101 having a pre-registered first short address. A monitoring device 101 that has failed to transfer information to another monitoring device 101 transfers information to another monitoring device 101 having a pre-registered second short address.

In this way, different short addresses are fixedly assigned to a plurality of monitoring devices 101, and each monitoring device 101 transfers information to another monitoring device 101 having a pre-registered short address. can transmit information.

Further, when the monitoring device 101 fails to transfer information to the other monitoring device 101 having the first short address, the configuration for transferring the information to the other monitoring device 101 having the second short address enables, for example, Even if information cannot be transferred to the monitoring device 101 in the next stage, the information can be transmitted to other monitoring devices 101 in the subsequent stages by skipping the monitoring device 101 in the next stage. As a result, delays in information transfer can be prevented, and information can be transmitted more reliably.

Therefore, in the communication system according to the embodiment of the present invention, it is possible to realize more stable operation in the power system.

In addition, in the communication system according to the embodiment of the present invention, the monitoring device 101 that has failed to transfer information to another monitoring device 101 having the second short address has the pre-registered third short address. , to transfer information to other monitoring devices 101 .

With such a configuration, for example, even if a situation occurs in which information cannot be transferred even if the monitoring device 101 in the next stage is skipped, the monitoring device 101 is further skipped and the information is transferred to other monitoring devices in the subsequent stages. can be transmitted. Thereby, information can be transmitted more reliably.

In addition, in the communication system according to the embodiment of the present invention, the monitoring device 101 generates a wireless packet containing its own short address and sequence number as the source and transmits it to the other monitoring devices 101 . If the short address and sequence number included in the newly received packet overlap with the short address and sequence number included in the already received wireless packet, the monitoring device 101 discards the newly received wireless packet.

With such a configuration, for example, it is possible to prevent a plurality of monitoring devices 101 from transferring packets with the same content due to retransmission of wireless packets, thereby preventing a large number of unnecessary wireless packets from being transmitted between the monitoring devices 101 .

Further, in the communication system according to the embodiment of the present invention, the monitoring device 101 transfers the measurement information indicating the measurement result of the sensor 111 in the monitoring device 101 and the sensor in the other monitoring device 101 received from the other monitoring device 101. At least one of transfer of measurement information indicating the measurement result of 111 is performed.

With such a configuration, it is possible to prevent the transfer of the measurement information indicating the measurement result of the sensor 111 from being delayed, and to transmit the measurement information more reliably. Therefore, it is possible to more reliably transmit the information indicating the location of the lightning strike to the power transmission equipment.

Also, in the communication system according to the embodiment of the present invention, the plurality of monitoring devices 101 includes a monitoring parent device 102 that performs multi-hop communication, and a plurality of monitoring child devices 103 that can communicate with the monitoring parent device 102. . For each of the upward direction from each supervisory device 103 to the supervisory parent device 102 and the downward direction from the supervisory parent device 102 to each supervisory device 103, each supervisory device 103 has a first short address and a second short address. It holds the short address separately. The first short address held by each supervisor device 103 is exclusive in each of the upstream and downstream directions. In each of the upstream direction and the downstream direction, the second short address held by each supervisory device 103 is assigned to the supervisory device 103 positioned after the supervisory device 103 to which the first short address is assigned. It is

With such a configuration, the physically closest monitoring device 101 can be set as the first transfer destination in the uplink direction and the downlink direction along the arrangement direction of the plurality of monitoring devices 101, so the wireless communication environment has deteriorated. It is possible to improve the reliability of information transmission in the case.

Also, the monitoring device 101 according to the embodiment of the present invention is a monitoring device in a communication system 301 that is used in a power system and has a plurality of monitoring devices 101 . A different terminal identifier is fixedly assigned to each of the plurality of monitoring devices 101 . The monitoring device 101 includes a storage unit 108 that stores a terminal identifier, and a communication unit 50 that transfers information to another monitoring device 101 having the pre-registered first terminal identifier. When the transfer of information to another monitoring device 101 fails, the communication unit 50 transfers the information to another monitoring device 101 having the previously registered second terminal identifier.

In this way, a terminal identifier different from that of other monitoring devices 101 is fixedly assigned, and the communication unit 50 transfers information to the other monitoring device 101 having a pre-registered terminal identifier. can transmit information. Further, when the communication unit 50 fails to transfer information to the other monitoring device 101 having the first terminal identifier, by transferring information to the other monitoring device 101 having the second terminal identifier, for example, Even if information cannot be transferred to the monitoring device 101 in the next stage, the information can be transmitted to other monitoring devices 101 in the subsequent stages by skipping the monitoring device 101 in the next stage. As a result, delays in information transfer can be prevented, and information can be transmitted more reliably. Therefore, more stable operation can be realized in the power system.

Also, in the communication system according to the embodiment of the present invention, the plurality of monitoring devices 101 serially transmit information via wireless transmission paths.

Such a configuration simplifies the procedure of wireless communication, so that information can be transferred using a transmission path with no or greatly relaxed hop count limit.

The above-described embodiments should be considered as illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all changes within the meaning and scope equivalent to the scope of the claims.

The above description includes the features appended below.
[Appendix 1]
A communication system for use in a power system and comprising a plurality of monitoring devices,
The plurality of monitoring devices are installed on a plurality of steel towers, respectively, and transfer at least one of measurement information indicating measurement results of sensors in the monitoring device or the measurement information received from another monitoring device,
Different terminal identifiers are fixedly assigned to the plurality of monitoring devices, respectively;
The plurality of monitoring devices are capable of transferring information to other monitoring devices in subsequent stages having a pre-registered first terminal identifier,
The communication system according to claim 1, wherein the monitoring device, for which transfer of information to the other monitoring device has failed, transfers information to the next other monitoring device in the next stage having the second terminal identifier registered in advance.

2 steel tower 3 overhead ground wire 4 power transmission line 101, 101_0 to 101_4 monitoring device 102 monitoring parent device 103, 103_1, 103_2 monitoring child device 50, 104, 105 communication unit 106 battery 107 control unit 108 storage unit 111 sensor 151 collection device 181 higher order Device 301 Communication system T, T1, T2 Monitoring system TL1, SL1 First list information TL2, SL2 Second list information

Claims (5)

A communication system for use in a power system and comprising a plurality of monitoring devices,
Different terminal identifiers are fixedly assigned to the plurality of monitoring devices, respectively;
the plurality of monitoring devices are capable of transferring information to other monitoring devices;
the plurality of monitoring devices include a monitoring parent device that performs multi-hop communication and a plurality of monitoring child devices capable of communicating with the monitoring parent device;
each of the monitor child devices holds list information indicating the terminal identifiers of all the monitor child devices in the communication system;
The supervisory child device that fails to transfer information to the supervisory child device at the next stage in the order indicated by the list information refers to the list information, and the supervisory child device at the succeeding stage or later in the order exists. case, the communication system for transferring information to the supervisory child device in the next stage and thereafter . The supervisory child device for which information transfer to the supervisory device in the succeeding stage or later has failed refers to the list information, and monitors the supervisory child device for which the transfer has failed in the next stage in the order. 2. The communication system according to claim 1 , wherein when a child device exists , the information is transferred to said monitoring child device in the next stage. the monitoring device generates a packet including the terminal identifier of the monitoring device and a sequence number as a transmission source and transmits the packet to another monitoring device;
When the terminal identifier and the sequence number contained in the newly received packet overlap with the terminal identifier and the sequence number contained in the already received packet, the monitoring device controls the newly received packet. 3. A communication system according to claim 1 or claim 2, wherein packets are discarded. The monitoring device performs at least one of transfer of measurement information indicating the measurement result of the sensor in the monitoring device and transfer of measurement information indicating the measurement result of the sensor in the other monitoring device received from the other monitoring device. 4. A communication system according to any one of claims 1 to 3, wherein: The monitoring device in a communication system that is used in a power system and includes a plurality of monitoring devices,
Different terminal identifiers are fixedly assigned to the plurality of monitoring devices, respectively;
a storage unit that stores the terminal identifier;
a communication unit that transfers information to the other monitoring device having the pre-registered terminal identifier ;
the plurality of monitoring devices include a monitoring parent device that performs multi-hop communication and a plurality of monitoring child devices capable of communicating with the monitoring parent device;
The storage unit holds list information indicating the terminal identifiers of all the monitoring child devices in the communication system,
If the communication unit fails to transfer information to the next-stage monitor child device in the order indicated by the list information, the communication unit refers to the list information, and if there is a next-stage or later monitor child device in the order. , a monitoring device that transfers information to the monitoring child device in the next stage or later ;

Images