JPH03113551U - - Google Patents

Description

[Brief explanation of drawings]

Fig. 1 is a diagram showing the configuration of one embodiment of the present invention, Fig. 2 is a diagram for explaining the outline of the operation for identifying a disconnection point in the embodiment of Fig. 1, and Fig. 3 is a diagram showing the configuration of an embodiment of the present invention. FIG. 4 is a flowchart illustrating an operation procedure for performing an operation and identifying a disconnection point that has occurred in bus B. FIG. 4 is a diagram illustrating an example of a conventional communication system. 1...Communication device, 2...Bus connection section, 3...
...Relay for bus A, 4...Relay for bus B, 5...
...Control unit, 6, 7... Transmitter/receiver, 8... Relay control means for bus A, 9... Relay control means for bus B, 10... Disconnection point specifying means, 11... Specification result output terminal, P ₁ ~ _P4 ...Port for connecting a bus, D1 _{~ Dn} ...Identification number for distinguishing each communication device, A, B...Duplicated communication bus.

Claims (1)

[Claims for Utility Model Registration] Duplicated first and second communication buses A and B
A plurality of communication devices D ₁ to D _n that can communicate with each other using
A mechanism for identifying a disconnection point by controlling communication between the plurality of communication devices D ₁ to _{D n} when a disconnection occurs in the communication bus, wherein each of the communication devices D ₁ to _{D n} first and second ports P ₁ and P ₂ for the first communication bus A; third and fourth ports P 3 and P 4 for the second communication bus B; and the first and second ports P ₃ and P ₄ for the second communication bus B. The first port P of the first communication bus A is provided between ports P ₁ and P ₂ of the first communication bus A.
Provided between the _first relay 3, which can arbitrarily divide and terminate both the line on the first side or _{the second} port P and the line on the second side, and the third and fourth ports _P3 and _P4. and a third port P of the second communication bus B
A second relay 4 that can arbitrarily divide and terminate both the line on the _3rd side or the line on the 4th port _P4 side, and controls the opening and closing of the first and second relays 3 and 4. Relay control units 8 and 9; and the relay control units 8 and 9 of its own communication device.
or issue commands to the relay control units 8 and 9 of other communication devices via the communication buses A and B to control the operations of the relay control units 8 and 9, and based on the information obtained as a result. , the communication bus A
, B disconnection point identification means 10 for identifying the disconnection point
The disconnection point specifying means 10 of the communication device that executes the disconnection point specifying operation first communicates with another communication device, and determines whether the disconnection is based on the position of the own communication device. Confirm whether the first or third ports P ₁ , P ₃ exist in the direction, or the second or fourth ports P ₂ , P ₄ exist in the direction, and then check whether the other ports exist in the confirmed direction. A command is issued to the relay control units 8 and 9 of each communication device to open and close the relays 3 and 4 to establish a connection with the own communication device, and each time the relays 3 and 4 are controlled to open and close, The number of communication devices connected to the communication device is measured, and it is determined that a disconnection of communication buses A and B has occurred in the confirmed direction of the communication device with the maximum number of connected communication devices. A mechanism for identifying a disconnection point in a redundant communication bus.