JP3946943B2 - Bridge device and control command relay method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bridge device that relays a control command transmitted from an operating device to an operated device via a network line including at least one high-speed serial bus.
[0002]
The present invention also relates to a control command relay method for relaying a control command transmitted from an operating device to an operated device via a network line including at least one high-speed serial bus.
[0003]
[Prior art]
The high-speed serial bus specified by IEEE1394-1995 has restrictions such as a maximum distance between nodes of 4.5 m and a maximum number of hops (1 hop for each cable connecting nodes) up to 16, and between rooms such as home networks. Problems occur during long-distance connections such as connection and communication with outdoor equipment. In order to solve this problem, standardization work such as long-distance transmission technology using P1394b and technical development of wireless 1394 have been carried out. Communication with the outdoors via a conventional telephone line is also possible. At this time, in order to connect different networks such as IEEE1394-1995 and P1394b, it is necessary to connect both networks via a bridge device.
[0004]
On the other hand, AV / C command standardization work has been carried out by the 1394 Trade Association as a means for sending and receiving commands on IEEE1394 and implemented in actual products. This AV / C command is premised on IEEE1394-1995 and does not consider long-distance connection via a bridge device. For this reason, problems arise when using AV / C commands over long distance connections. Specifically, in the AV / C command, the time from command reception to response response is set to 100 ms, and it is specified that some response is returned within this time. However, when assuming communication between rooms such as home networks and outdoor communication via a telephone line, the intervening bridge device or low-speed line such as wireless 1394 or telephone line becomes a bottleneck, resulting in communication delay or timeout. It can happen. For this reason, there is a problem that long-distance transmission cannot be performed by a device that assumes a single network. Also, polling the STATUS command, which is frequently used by current devices, between multiple rooms will cause problems with the home network backbone traffic.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide the following bridge device and control command relay method.
[0006]
(1) A bridge device capable of preventing a timeout that occurs during a long-distance connection via a network.
[0007]
(2) A bridge device that can prevent an increase in traffic on the backbone that occurs during a long-distance connection via a network.
[0008]
(3) A bridge device capable of transmitting and receiving commands between devices via different networks.
[0009]
(4) A control command relay method capable of preventing a timeout that occurs during a long-distance connection via a network.
[0010]
(5) A control command relay method capable of preventing an increase in traffic on the backbone that occurs during a long distance connection via a network.
[0011]
(6) A control command relay method capable of transmitting and receiving commands between devices via different networks.
[0012]
[Means for Solving the Problems]
In order to solve the above problems and achieve the object, the bridge device and the control command relay method of the present invention are configured as follows.
[0013]
(1) The present invention provides a bridge device that relays a control command transmitted from an operating device to an operated device via a network line including at least one high-speed serial bus. Storage means for acquiring and storing, and response means for responding to a status acquisition request from the operating device using the status of the operated device stored in the storing device.
[0014]
(2) The present invention is required for an operating device in a bridge device that relays a control command transmitted from an operating device to an operated device via a network line including at least one high-speed serial bus. Acquisition means for acquiring the status monitoring item, and storage means for acquiring and storing the status of the operated device based on the status monitoring item acquired by the acquisition means.
[0015]
(3) The present invention can be used between devices in a bridge device that relays a control command transmitted from an operating device to an operated device via a network line including at least one high-speed serial bus. Investigation means for investigating the types of state monitoring commands, and selection means for selecting a command to be used at the time of obtaining the state between devices based on the investigation result by the investigation means.
[0016]
(4) The present invention relates to a control command relay method for relaying a control command transmitted from an operating device to an operated device via a network line including at least one high-speed serial bus. A first step of acquiring and storing the state; and a second step of responding to the state acquisition request from the operating device using the state of the operated device stored in the first step.
[0017]
(5) The present invention is necessary for an operating device in a control command relay method for relaying a control command transmitted from an operating device to an operated device via a network line including at least one high-speed serial bus. And a second step of acquiring and storing the state of the operated device based on the state monitoring item acquired in the first step.
[0018]
(6) The present invention provides a control command relay method for relaying a control command transmitted from an operating device to an operated device via a network line including at least one high-speed serial bus. A first step of investigating the types of status monitoring commands that can be used; and a second step of selecting a command to be used at the time of obtaining the status between the devices based on the investigation result of the first step.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0020]
FIG. 1 is a block diagram schematically showing the configuration of a bridge device according to the present invention. This bridge device relays a control command or the like transmitted from the control device (operating device) C1 to the controlled device (operated device) C2.
[0021]
As shown in FIG. 1, the bridge device includes a first transmission / reception unit 1, a second transmission / reception unit 2, a command response unit 3, a command transfer unit 4, a state management table 5, a state management item acquisition unit 6, a state monitoring unit 7, A support command investigation unit 8 and a timeout management unit 9 are provided.
[0022]
The transmission / reception unit 1 receives a command transmitted from the control device C1, determines whether the received command is a command that can be responded by the bridge device, and sends the received command to the command response unit 3 or the command transfer unit 4. The command response unit 3 refers to the information in the state management table 5 and responds to the command transmitted from the control device C1. The command transfer unit 4 transfers the command received by the transmission / reception unit 1 to the control device C2 via the transmission / reception unit 2. At the time of transfer, the command transfer unit 4 converts commands as necessary.
[0023]
The support command investigation unit 8 investigates the support command of the controlled device C2, and notifies the transmission / reception unit 1 and the command transfer unit 4 of the investigation result. In the transmission / reception unit 1, when the investigation result of the support command investigation unit 8 is available, the command response unit 3 determines whether the command from the control device C 1 can respond with reference to the investigation result. Further, when the investigation result of the support command investigation unit 8 is available, the command transfer unit 4 refers to the information and converts the command.
[0024]
The state monitoring unit 7 monitors the state of the controlled device C2 via the transmission / reception unit 2, and accumulates the monitoring result in the state management table. The status monitoring item acquisition unit 6 acquires status monitoring items required by the control device C1 via the transmission / reception unit 1. The state monitoring unit 7 refers to the information of the state monitoring item required by the control device C1 acquired by the state monitoring item acquisition unit 6, and determines an item for monitoring the state.
[0025]
The timeout management unit 9 monitors the timeout of the command transferred by the command transfer unit 4, and transmits a response to the control device C1 before the timeout occurs under a preset condition. This can prevent timeout.
[0026]
FIG. 2 is a diagram illustrating an installation example 1 of the bridge device illustrated in FIG. 1. Specifically, it is a diagram showing an example in which the bridge device of the present invention is applied to bridge 1 in FIG.
[0027]
The Controller device (control device) periodically transmits a status confirmation command to the Target device (controlled device). Specific examples of the controller device include a digital television, a digital STB (set top box), and a PC (personal computer). Specific examples of target devices include devices such as DVHS and DVD. As a specific example of the status confirmation command, there is a STATUS command in an AV / C command standardized by the 1394 Trade Association.
[0028]
When this Controller device and Target device are connected via a plurality of networks, they are connected via a bridge device as shown in FIG. At this time, a delay may occur depending on the type and number of bridge devices and relay networks. In addition, there is a problem such as a delay due to an increase in traffic in the relay network. Specifically, the AV / C command stipulates that some response be returned within 100 ms for a command, but due to the delay associated with relaying multiple networks, there is a response timeout that did not occur on a single network. It can happen.
[0029]
In the present invention, a status check request from the Controller device is detected by Bridge1. Bridge1 checks the status of the Target device in advance and stores it in the status management table, and responds to the status check request from the Controller device using the information in the status management table in Bridge1 to prevent timeout. Can do.
[0030]
In the present invention, the support command of the target device is confirmed, and if the status notification command corresponding to the status confirmation command from the controller device is available, the status of the target device is confirmed using the status notification command. As a specific example of the status notification command, there is a NOTIFY command defined by AV / C. The NOTIFY command is a command that instructs the target device to notify the request source when the state changes. Since notification is performed only when the status changes, the load on the network can be reduced compared to the method of periodically checking the status with the STATUS command.
[0031]
FIG. 3 is a diagram illustrating an installation example 2 of the bridge device illustrated in FIG. 1. FIG. 2 shows an example in which the bridge device of the present invention is applied only to Bridge 1, whereas FIG. 3 shows an example in which the bridge device of the present invention is applied to a plurality of locations in a relay network such as Bridge 1 and Bridge 2. FIG.
[0032]
In FIG. 3, in response to periodic status confirmation command transmission (polling) from the Controller device, a command that can be received by Bridge2 is investigated, and the status is acquired using a status notification command corresponding to the status confirmation command. Bridge2 investigates commands that can be received by the Target device. This operation example shows an example in which the target device does not support the status notification command. In this case, Bridge 2 periodically sends a status check command to check the status of the Target device, and stores it in the Bridge 2 status management table. When the state changes, Bridge2 returns a response to the state notification command to Bridge1, and updates the state management table of Bridge1.
[0033]
In this way, by applying the bridge device according to the present invention at a plurality of locations, even when the controller device and / or the target device do not support the state notification command, the state is not detected on the network relay route. Notification commands can be used, and traffic can be reduced.
[0034]
FIG. 4 is a diagram illustrating an example of the state management table.
[0035]
The state name indicates a name related to the state of the target device stored in the bridge device. Which state is stored in the state management table is determined by a state monitoring request from the Controller device. The state indicates a specific state value of each state name in the confirmation destination device. For example, the status for POWER is indicated by ON / OFF. The monitoring command indicates a command used for monitoring the status of the monitoring target. The commands used for status monitoring check the implementation status of the status check command (STATUS) and status notification command (NOTIFY) for each status name, and if the status notification command is available, use the status notification command. Prioritize. The monitoring target indicates the monitoring target device. A device that supports IEEE1394 has an identifier (GUID) that is uniquely determined for each device. In this embodiment, this GUID is stored in an item to be monitored.
[0036]
FIG. 5 is a diagram illustrating a processing example in response to a command using the state management table in the bridge device installation example 1 illustrated in FIG. 2.
[0037]
The STATUS command from the Controller device to the Target device is relayed to Bridge1. At this time, if the NOTIFY command corresponding to the status check command is implemented in the Target device, Bridge 1 acquires the status of the Target device using the NOTIFY command and stores it in the status management table. Immediately after receiving the NOTIFY command, the Target device returns the current status as an INTERIM response. In this embodiment, PLAY is returned as the tape running state. This PLAY is stored in the state management table, and Bridge 1 thereafter refers to the state management table and returns the PLAY state as a response to the inquiry from the controller device. A REJECT response (rejection response) is returned to the status confirmation command received before the status management table is initialized (before the target device status is stored). In other words, when the target information is not stored in the status management table, a REJECT response is returned to the status confirmation command from the Controller device.
[0038]
FIG. 6 is a diagram illustrating a processing example at the time of command transfer in the installation example 1 of the bridge device illustrated in FIG. 2.
[0039]
Commands that cannot be responded to by the status management table, such as device operation commands, are transferred to the target device and processed. A specific example of the device operation command is a CONTROL command defined by AV / C. When a command is transferred, there is a possibility that a timeout that does not occur in the local network may occur due to a delay caused by the relay network or other bridge devices. In this embodiment, when the timeout management unit 9 detects the timeout of the transferred command, it returns a temporary response to the Controller device instead of the Target device.
[0040]
A specific example of the provisional response is an INTERIM response defined by AV / C. Then, by transferring the actual response from the Target device to the Controller device, timeout on the Controller side can be prevented. If a temporary response is received from the target device after the temporary response is returned by the timeout management unit 9, it is discarded.
[0041]
FIG. 7 is a diagram showing an operation flow of the command response unit 3 in the bridge device of the present invention.
[0042]
First, a state monitoring command is received (step S1), and it is confirmed whether information corresponding to the received command is stored in the state management table (step S2). If stored (YES in step ST2), the corresponding state information is read (step S3), and a response to the received state monitoring command is generated and transmitted (step S4). If information corresponding to the received command is not found (step S2, NO), the received state monitoring command is transferred to another network connected to the bridge device (step S5).
[0043]
FIG. 8 is a diagram showing an operation flow of the state monitoring unit 7 in the bridge device of the present invention.
[0044]
First, one item is selected from the state monitoring table (step S1). It is confirmed whether the status notification command is supported (step S2). When the status notification command is not supported (step S2, NO), a status confirmation command is transmitted to the status monitoring target device (Target device) and a response is waited (step S3). After receiving the response to the status confirmation command (step S4), the status management table is updated according to the content of the response (step S5). It is confirmed whether or not the state monitoring is continued (step S6). When the state monitoring is continued (step S6, YES), after waiting for a certain time (step S7), the processing from step S3 to step S5 is repeated. If the state monitoring is not continued (step S6, NO), the process is terminated. Whether or not to continue status monitoring is determined based on a change in the request contents from the status monitoring requesting device (Controller device).
[0045]
When the status notification command is supported (step S2, YES), the status notification command is transmitted (step S8), and a response is waited for. Thereafter, a status notification response regarding the current status is received (step S9), and the status monitoring table is updated according to the content (step S10). Thereafter, the status notification response after the status update is received (step S11), and the status management table is updated according to the content (step S12). It is confirmed whether or not the state monitoring is continued (step S13). When the state monitoring is continued (step S13, YES), the processing from steps S8 to S12 is repeated. If the state monitoring is not continued (step S13, NO), the process ends.
[0046]
FIG. 9 is a diagram showing a first operation flow of the state monitoring item acquisition unit 6 in the bridge device of the present invention.
[0047]
First, a status confirmation command from the controller device is received (step S1), and a monitoring item is added to the status management table according to the contents of the command (step S2).
[0048]
FIG. 10 is a diagram showing a second operation flow of the state monitoring item acquisition unit 6 in the bridge device of the present invention.
[0049]
First, after receiving the first state confirmation command (step S1), a timer for time measurement is started (step S2). It is confirmed whether a command is received within the specified time (step S3). If no command is received (step S3, NO), the process is terminated as a timeout. When a command is received within the specified time (step S3, YES), the time interval from the previous state confirmation command is measured (step S4). It is confirmed whether the time interval has been measured the specified number of times (step S5). If the specified number of times has not been measured (step S5, NO), the processes of steps S3 and S4 are repeated the specified number of times. After measuring the specified number of times (step S5, YES), the variance of the measured command interval is measured (step S6), and if the variance falls within the set threshold (step S7, YES), an item is added to the state management table ( Step S8).
[0050]
FIG. 11 is a diagram showing an operation flow of the support command examining unit 8 in the bridge device of the present invention.
[0051]
First, the target device is inquired about support of the status notification command (step S1). The support is confirmed (step S2), and if it is supported (step S2, YES), the monitoring command in the state management table is set to the state notification command (step S3). If not supported (step S2, NO), an inquiry about support of the status confirmation command is made (step S4). Further, it is confirmed whether it is supported (step S5). If it is supported (step S5, YES), the monitoring command is set as a status confirmation command (step S6). If it is not supported (step S5, NO), it is determined that there is no means for monitoring the state of the target device, and the item is deleted from the state management table (step S7).
[0052]
FIG. 12 is a diagram showing an operation flow of the timeout management unit 9 in the bridge device of the present invention.
[0053]
First, after command transfer (step S1), a timer is started (step S2). When a timeout is detected (step S3, YES), a temporary response is returned as a response (step S4).
[0054]
As described above in detail, according to the present invention, the state (STATUS) of the target device is held in the bridge device, and an appropriate response is returned to the request from the controller, thereby preventing timeout and improving the response speed. Can do. Further, when a NOTIFY command corresponding to the STATUS command can be used, traffic can be reduced by using NOTIFY instead of STATUS.
[0055]
Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention in the implementation stage. In addition, the embodiments may be appropriately combined as much as possible, and in that case, the combined effect can be obtained. Further, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention Can be obtained as an invention.
[0056]
【The invention's effect】
According to the present invention, the following bridge device and control command relay method can be provided.
[0057]
(1) A bridge device capable of preventing a timeout that occurs during a long-distance connection via a network.
[0058]
(2) A bridge device that can prevent an increase in traffic on the backbone that occurs during a long-distance connection via a network.
[0059]
(3) A bridge device capable of transmitting and receiving commands between devices via different networks.
[0060]
(4) A control command relay method capable of preventing a timeout that occurs during a long-distance connection via a network.
[0061]
(5) A control command relay method capable of preventing an increase in traffic on the backbone that occurs during a long distance connection via a network.
[0062]
(6) A control command relay method capable of transmitting and receiving commands between devices via different networks.
[Brief description of the drawings]
FIG. 1 is a block diagram schematically showing a configuration of a bridge device according to the present invention.
FIG. 2 is a diagram illustrating an installation example 1 of a bridge device.
FIG. 3 is a diagram showing an installation example 2 of the bridge device.
FIG. 4 is a diagram illustrating an example of a state management table in a bridge device.
5 is a diagram illustrating a processing example when a command response is made using a state management table in the installation example 1 of the bridge device illustrated in FIG. 2; FIG.
6 is a diagram showing a processing example at the time of command transfer in the installation example 1 of the bridge device shown in FIG. 2; FIG.
FIG. 7 is a diagram illustrating an operation flow of a command response unit in the bridge device.
FIG. 8 is a diagram illustrating an operation flow of a state monitoring unit in the bridge device.
FIG. 9 is a diagram illustrating a first operation flow of a state monitoring item acquisition unit in the bridge device.
FIG. 10 is a diagram illustrating a second operation flow of the state monitoring item acquisition unit in the bridge device.
FIG. 11 is a diagram illustrating an operation flow of a support command examining unit in the bridge device.
FIG. 12 is a diagram illustrating an operation flow of a timeout management unit in the bridge device.
[Explanation of symbols]
C1 ... Control device (operating device), C2 ... Controlled device (operated device), 1 ... first transmission / reception unit, 2 ... second transmission / reception unit, 3 ... command response unit, 4 ... command transfer unit, 5 ... state management Table: 6 ... Status management item acquisition unit, 7 ... Status monitoring unit, 8 ... Support command investigation unit, 9 ... Timeout management unit

Claims (8)

In a bridge device that relays a control command transmitted from an operating device to an operated device via a network line ,
A measuring means for measuring the transmission interval of the status confirmation command;
When a status check command is received continuously a predetermined number of times at a transmission interval within a specified time, a status monitor item required by the operating device is determined based on the status check command, and the determined status monitor item is operated Storage means for acquiring and storing the state of the device;
Response means for responding to a status confirmation request from the operating device using the status of the controlled device stored in the storage means ;
A bridge device , comprising: a transmission unit that transmits a status confirmation command to a controlled device when information intended for a status confirmation request from an operating device is not stored in the storage unit .   Investigation means to investigate the types of commands that can be used between devices,
  The bridge device according to claim 1, further comprising a selection unit that selects a command to be used when acquiring a state between the devices based on a result of the survey performed by the survey unit.   An investigation means for investigating a status check command that can be used between devices and a status notification command that notifies the request source of a status change when the status changes;
  The operated device that can use the status notification command has selection means for selecting the status notification command in order to check the status of the operated device using the status notification command. The bridge device according to 1.   Monitoring means for monitoring the response time from the operated device;
  The bridge device according to claim 1, further comprising a response unit that returns a response indicating that processing is being performed to the operation device when the response time monitored by the monitoring unit exceeds a predetermined threshold.   In a control command relay method for relaying a control command transmitted from an operating device to an operated device via a network line,
  Measure the transmission interval of the status check command,
  When a status check command is received continuously a predetermined number of times at a transmission interval within a specified time, the status monitor item required by the operating device is determined based on the status check command, and the determined status monitor item is operated Get and store the device status,
  Responds to the status confirmation request from the operating device using the stored status of the controlled device,
  A control command relay method, comprising: transmitting a status confirmation command to a controlled device when information intended for a status confirmation request from an operating device is not stored.   Investigate the types of commands that can be used between devices,
  6. The control command relay method according to claim 5, wherein a command to be used at the time of acquiring a state between each device is selected based on the investigation result.   Check the status check command that can be used between devices and the status notification command that notifies the request source of the status change when the status changes
  6. The control according to claim 5, wherein for the operated device that can use the status notification command, the status notification command is selected in order to check the status of the operated device using the status notification command. Command relay method.   Monitor the response time from the operated device,
  6. The control command relay method according to claim 5, wherein when the monitored response time exceeds a predetermined threshold, a response indicating that processing is in progress is returned to the operating device.

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