JP2009088880A - Communication disconnecting circuit in failure time of wide area network communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To certainly disconnect communication control elements from a line in a higher speed than that in a control method by a software at the time of a failure of the communication control elements in a circuit which performs Ethernet communications with other information devices using the communication control elements. <P>SOLUTION: When a monitoring device and a circuit disconnecting device are connected to the communication circuit, and monitor the communication control elements, the circuit disconnecting device certainly and physically disconnects the elements from the line in high speed so as not to affect the whole line by incorrect output or runaway if failure of the communication control circuit is detected. Moreover, soundness is confirmed by comparing systems since the monitoring device uses a multiple system configuration. Therefore, it is possible to prevent overlooking/incorrect detection of the failure of the communication control device by potential failure of the monitoring device, and a high reliable system can be built. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention minimizes the influence on the entire line due to malfunction or runaway of the communication control element by providing a line disconnection device controlled by a highly reliable apparatus multiplexed at the output stage of the communication path. The present invention relates to a communication disconnection circuit at the time of failure of a wide area network (for example, Ethernet (registered trademark)) communication device.

  In a system that requires high reliability, it is necessary to prevent runaway / error output due to a failure of the communication control element from affecting the entire line.

  For example, in a railway system, in order to transmit an instruction from a host device to a train operator, the lighting control of a railway traffic signal as shown in FIG. 1 is performed. If an event such as continuous transmission of erroneous data to the line always occurs due to the runaway of the communication control element, communication between all the devices connected to the same line becomes impossible. It becomes impossible to control the signal light.

  Therefore, the train must be stopped in the entire section, which has a great influence on railway operation. In order to avoid the state, a mechanism for detecting a failure of the communication control element and disconnecting from the line is required. (Figure 2)

Conventionally, in communication such as 100BASE-TX and 100BASE-FX standardized by the Institute of Electrical and Electronics Engineers (IEEE) 802.3, disconnection from a communication path when a failure is detected is performed by software.
JP 2000-92105 A JP-A-10-93617

  In the conventional method, time is required for processing by software. For this reason, there is a problem that it is difficult to apply in a system that requires real-time performance.

  Further, in a system such as a railway system that requires particularly high reliability, it has been necessary to disconnect a circuit in hardware so that an element and a line can be surely disconnected in the event of a failure.

In view of the prior art, the present invention
(1) An abnormality of the communication control element can be detected. (2) When the communication control element fails, the communication control element can be disconnected from the line more quickly and reliably than the control method by software. (3) Communication due to a potential failure of the monitoring device. It is an object of the present invention to realize a communication path disconnection circuit that satisfies the condition of preventing a control element from overlooking a fault and preventing erroneous detection.

  The communication disconnection circuit at the time of failure in the Ethernet communication circuit of the present invention uses a communication control element and monitors the communication control element at the output stage of the communication path in the Ethernet communication circuit that communicates with other information devices via Ethernet. By adding a device and a line disconnecting device, detecting a failure of the communication control element, and physically disconnecting the communication control element and the line, the influence on the entire line can be reduced.

  Specifically, the present invention monitors a communication control element by connecting a monitoring device and a line disconnection device to the communication circuit shown in FIG. The monitoring device periodically communicates with the communication control element to check the soundness of the communication control element. When the monitoring device detects a failure of the communication control element, it is physically disconnected from the line by the line disconnection device so as not to affect the entire line due to erroneous output / runaway of the communication control element (FIG. 4). By adopting a physical separation configuration, it is possible to perform the separation more quickly and reliably than software control.

  In addition, the monitoring device adopts a multi-system configuration and performs self-monitoring by comparison, thereby preventing oversight / false detection of a communication control element failure due to a latent failure of the monitoring device and improving reliability ( FIG. 5). A flowchart of a series of operations is shown in FIG.

  According to the present invention, it is possible to prevent an influence on the entire line due to a runaway / malfunction of the communication control element.

Further, when a failure of the communication control element is detected, the line disconnection device physically disconnects the communication control element and the line, so that the following effects can be obtained as compared with the line disconnection by software control.
(1) Since reliable line disconnection is possible, a highly reliable system can be constructed.
(2) Since the line can be disconnected at high speed, the influence on the entire line can be reduced.

  In addition, by using a multiple system configuration, the monitoring device can confirm the soundness by system comparison, and therefore, it is possible to prevent oversight / false detection of a communication control device failure due to a latent failure of the monitoring device. A high system can be constructed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 7 shows an application of the failure communication disconnection circuit of the present invention to an electronic interlocking device for controlling railway signal lights and switchboards. The electronic interlocking device 14 sends a control message from the host device to the control terminals 15 to 17, and the control terminals 15 to 17 perform drive control of the signal lights 30 to 32.

  When there is no abnormality in the communication control elements 22 to 25, the line disconnecting devices 26 to 29 do not operate and can communicate with all the elements.

  If the communication control element 23 has failed, the CPU unit 19 detects the failure, operates the line disconnecting device 27 to disconnect from the line, and outputs the signal to the safe side (indicating red if the signal lamp is stopped).

  Since the malfunctioning control terminal 15 and other devices are physically separated, the other devices are not affected by the runaway / malfunction of the communication control unit 23. For this reason, it is possible to minimize the influence rather than stopping the train in all sections connected by the line.

  Moreover, CPU part 18-21 has confirmed the soundness by comparison of both systems by taking a double system structure.

FIG. 1 shows a railway traffic signal. FIG. 2 is an explanatory diagram of the influence on the line due to the element failure. FIG. 3 is an explanatory diagram when the communication control element according to the present invention is normal. FIG. 4 is an explanatory diagram when the communication control element is abnormal according to the present invention. FIG. 5 is an explanatory diagram of the duplication of the monitoring device. FIG. 6 is a flowchart of the present invention. FIG. 7 is an application diagram to the electronic interlocking device according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Communication control element 2 Monitoring apparatus 3 Line disconnection device 4 Connector and transformer 5 Communication control element 6 Monitoring apparatus 7 Connector and transformer 8 Load drive power supply 9 Communication control element 10 Monitoring element A
11 Monitoring element B
12 Line disconnecting device 13 Connector and transformer 14 Railway electronic interlocking device 15 Control terminal A
16 Control terminal B
17 Control terminal C
18 CPU for electronic interlocking device 19 19 CPU for control terminal 15 20 CPU for control terminal 16 21 CPU for control terminal 17 22 Communication control element for electronic interlocking device 23 Communication control element for control terminal 15 24 Control terminal 16 Communication control element for control terminal 25 Communication control element for control terminal 17 Line disconnection device for electronic interlocking device 27 Line disconnection device for control terminal 15 28 Line disconnection device for control terminal 16 29 Line disconnection device for control terminal 17 30 Railway signal light A
31 Railway Signal Light B
32 Railway Signal Light C

Claims (2)

  A communication disconnection circuit at the time of a failure in a wide area network (for example, Ethernet (registered trademark)) communication circuit that uses a communication control element to communicate with another information device via a wide area network, and is an output stage of the communication path A communication control element monitoring device and a line disconnection device are added to the communication control element to detect a failure of the communication control element and physically disconnect the communication control element and the line, thereby reducing the influence on the entire line. Communication disconnection circuit at the time of failure.   The failure communication disconnection circuit according to claim 1, wherein a multiplexed monitoring device is used as the monitoring device, and a self-diagnosis by comparison is performed, thereby overlooking a communication control element failure due to a potential failure of the monitoring device. A communication disconnection circuit at the time of failure characterized in that the probability of erroneous detection can be reduced.

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