JP2518514B2 - Automatic fault detection system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic fault detection system in a bus type network.

[0002]

2. Description of the Related Art Conventionally, in a bus type network,
In case of a cable failure such as disconnection of the network transmission path, the network transmission path is duplicated, and when a cable failure such as a sudden disconnection of the network transmission path or the termination connector occurs, the network-compatible OS detects the failure occurrence. A method to prevent the entire network system from going down by notifying the operator of the failure information and continuing the service after switching from the network transmission path where the cable failure occurred to the other network transmission path I was taking it.
Further, the search for the location of the failure has been performed artificially based on the failure information.

[0003]

In the above-mentioned conventional bus type network, when a cable failure such as a sudden disconnection of a network transmission line or a terminal connector occurs, the network compatible OS detects and notifies the occurrence of the failure. Although it was possible, it is necessary to artificially search for the location of the failure, and as the network scale increases and the system becomes more complicated, it becomes difficult to find the failure location, which takes time and man-hours. was there.

[0004]

A first aspect of the present invention is a cable failure such as a disconnection occurring on a network transmission line of a working system in a two-system bus type network containing a plurality of terminal devices, a working system and a non-working system. In the automatic failure detection system for automatically detecting a failure, when a cable failure in the working network transmission line connected to the two network transmission paths is detected, an emergency packet is broadcasted through the non-working network transmission path to output test information. When the emergency packet is received from the protection network transmission path between the bus monitoring processor that analyzes the reception and outputs the analysis result and the network transmission paths of the two systems and each of the terminal devices, the protection network transmission The network is connected to the terminal device under it as a new operational network transmission line. The operation network transmission line is individually tested by a predetermined algorithm from the self-connection position to a left and right at a predetermined time according to its own connection position on the transmission line, and the test result is used as the test information for the new operation. It is characterized in that it is provided with an automatic failure detection mechanism for outputting through a system network transmission line.

According to a second aspect of the present invention, the automatic failure detection mechanism uses a first information line and a second information line, a third information line and a fourth information line, and the two-system network transmission. Two connectors that individually draw the lines, each having a connection function with the first information line according to a first instruction for the working network transmission line, and an individual terminating function for each of the left and right directions. One connector and a second connector having a connection function with the second information line according to a second instruction for the non-operation system network transmission line, and a termination function for each of the leftward and rightward directions; A switching circuit for exclusively connecting the one information line and the second information line, the third information line and the fourth information line to each other in response to a switching instruction, and the operation system network transmission line. Signal the first Connector, a network interface circuit relaying to the terminal device via the first information line and the third information line, and the second connector, the second information line and the non-operation network transmission line. When the emergency packet is received via the fourth information line, the first information line and the fourth information line are simultaneously connected to the second information line and the third information line through the switching circuit. After that, at a predetermined time according to the connection position of the mechanism itself in the network transmission line, the first connector of the first connector via the first information line and the fourth information line for the operational network transmission line. The left and right sides of the operational network transmission line are individually tested based on a test algorithm predetermined using the termination function, and the second information line and the second information line are transmitted through the switching circuit. Characterized in that it is composed of a fault detection circuit for outputting through the fourth of the through the second connector as the test information the test results after connecting the information lines non-active network transmission path.

[0006]

The present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In FIG. 1, the automatic fault detection system of the present invention comprises a bus monitor processor 0, two network transmission lines: a network transmission line 1 and a network transmission line 2, and all terminals A connected to the network.
It is composed of automatic fault detection mechanisms 3a to 3d built in B, C, and D. Here, the bus monitoring processor 0 can instantly detect the occurrence of a failure when a failure such as a cable disconnection occurs on the network, and also transfers an emergency packet that means a network transmission path switching command to the data transfer. It is possible to make a call to the fully automatic fault detection mechanisms 3a to 3d via a network transmission line not used for the service.

FIG. 2 is a block diagram of an automatic failure detection mechanism for detecting the location of a failure when a failure occurs. This automatic failure detection mechanism is provided in association with each terminal connected to the network, and has a connector 31 connected to the network transmission line 1, a connector 32 also connected to the network transmission line 2, and a failure detection unit. Fault detection circuit 33 that operates in accordance with the present invention, a network interface circuit 34 that transmits signals received from the network transmission lines 1 and 2 to a network interface board, and further to a terminal CPU, a connector 31 and a connector 32, respectively. It is composed of a switching circuit 35 for switching to each of the interface circuits 34.

The above-mentioned fault detection circuit 33 has a function of detecting a fault occurrence point when a fault occurs on the network, and a CPU 301 for separating a fault point.
And a packet transmission / reception circuit 302 for transmitting and receiving packets
And the unique address held by this mechanism (a serial number held by all of the automatic failure detection mechanisms. In this embodiment, the character string starts with "a", but the digit of the character string in actual operation is (The number is arbitrary), an address detection circuit 304 for detecting an address contained in the received packet from the received packet, a decoding circuit 305 for decoding the meaning of the received packet, and a decoded content The control circuit 306 executes control based on

FIG. 3 is a block diagram of the connectors 31 and 32 for connecting the network transmission line and the internal circuit of the automatic failure detection mechanism. In the connector 31 (the connector 32 also has the same configuration as the connector 31), a termination circuit 311 that terminates in the left direction from the junction point with the network transmission line 1 and outputs the input signal in the left direction is output, and similarly in the network transmission line 1 The termination circuit 312 that terminates in the right direction from the junction point with and returns the input signal to the right direction and the internal circuit of the automatic failure detection mechanism are connected to the network transmission line or switched to the termination circuit. Switching circuit 3
13, 314.

Next, with reference to FIGS. 2 and 3, the basic operation until the automatic failure detection mechanism detects a location of a cable failure on the network transmission line will be described below.

The fault detection operation of the automatic fault detection mechanism starts when an emergency packet is received from the bus monitoring processor. Further, the failure detection operation described below detects a failure in order from the automatic failure detection mechanism having the unique address “a” to the automatic failure detection mechanism having the unique addresses “b”, “c” ... We will proceed with the operation.

First, the CPU 301 instructs the control circuit 306 to set the switching circuit 313 inside the connector 31 to the termination circuit 3.
11 (the switching), and the switching circuit 314 is instructed to connect (switch) the network transmission path side. The control circuit 306 executes control according to an instruction from the CPU 301. By this operation, the network transmission line 1
, The left side of the network is terminated and only the right side of the network can communicate. Next, the packet transmission / reception circuit 302 sends a test packet to the unspecified number of automatic failure detection mechanisms, which means that a response packet including a unique address is returned. Then, when even one packet of the response packet including the unique address from the other automatic failure detection mechanism is received, the unique address is detected by the address detection circuit 304 from the received response packet, and the unique address is included. After confirming the above, it is determined that there is no cable failure in the right direction of the network (if a response packet from another automatic failure detection mechanism can be received, there is no failure in the network transmission path), The failure detection operation for the right side of the network ends. On the other hand, when the response packet from another automatic failure detection mechanism is not received, the CPU 3
01 determines that a cable failure has occurred in the right direction of the network, executes control by the control circuit 306, connects the switching circuit 314 in the connector 1 to the terminating circuit 312 side (switches), and terminates the right direction of the network. After that, the failure detection operation to the right of the network ends.

Next, the CPU 301 commands the control circuit 306 to connect (switch) the switching circuit 313 to the network transmission line side. The control circuit 306 uses the CP
Under the command of U301, the switching circuit 313 is controlled. Here, with respect to the network transmission line 1, the right side of the network is terminated, and communication is possible only in the left side of the network. Then, the same operation as the failure detection operation executed for the right side of the network is executed for the left side of the network. When even one response packet is received from another automatic failure detection mechanism, it is determined that there is no cable failure in the left direction of the network, and the failure detection operation for the left direction of the network ends. On the other hand, if no response packet is received,
It was judged that a cable failure occurred in the left direction of the network, and the switching circuit 314 was switched from the termination circuit 312 to the network transmission line side again (connecting to the right direction network)
After that, the failure detection operation to the left of the network ends. Finally, under the instruction of the CPU 301, the control circuit 306
However, after executing the control for connecting (switching) the fault detection circuit 33 and the network transmission line 2 to the switching circuit 35, the result of performing the fault detection operation together with the unique address held by the automatic fault detection mechanism (the network transmission line 1
Error occurrence / no abnormality in the right direction and abnormality occurrence / no abnormality in the left direction) to the bus monitoring processor 0. Then, when the notification to the bus monitoring processor 0 is completed, the control circuit 306 again executes control for connecting (switching) the network transmission line 2 and the network interface circuit 34 to the switching circuit 35, and this automatic failure detection mechanism. The failure detection operation in is ended.

The above is the fault detection operation in one automatic fault detection mechanism.

Next, the operation procedure of the automatic fault detection system according to the present invention will be described with reference to FIGS.

As shown in FIG. 1, in the network, one bus monitoring processor 0 and two network transmission lines: network transmission line 1 and network transmission line 2
And four terminals (terminals A, B, C, D) incorporating the automatic failure detection mechanisms 3a, 3b, 3c, 3d are connected,
Usually, data communication is performed between the terminals using the network transmission line 1 (the network transmission line 2 is not used). In this embodiment, four terminals A, B, C, D (each having an automatic failure detection mechanism 3a, 3b, 3c, 3d built therein) are connected on the network for simplification of description. The operation procedure will be described, but the basic configuration and operation procedure remain the same even if the number of terminals increases.

Here, it is assumed that a cable failure has occurred on the network transmission line 1 between the terminals B and C. The bus monitoring processor 0 instantly detects the occurrence of a failure on the network transmission line 1, switches the network transmission line 2 to perform data communication, and uses the network transmission line 2 to automatically detect an emergency packet. Mechanism 3a, 3
Send to b, 3c, and 3d.

Automatic fault detection mechanism 3a, 3b, 3c, 3d
Then, the urgent packet transmitted from the bus monitoring processor is received by the packet transmission / reception circuit 302 in the failure detection circuit 33 via the connector 32. Then, based on the content of the decryption of the received packet in the decryption circuit 305, C
The PU 301 commands the control circuit 306 to switch the switching circuit 35. Based on the instruction, the control circuit 306 executes switching control to the switching circuit 35, and the connector 3
2 is connected to the network interface circuit 34 and the connector 31 is connected to the failure detection circuit 33,
The data communication transmission lines are switched to the network transmission line 2 all at once. Then, normal data communication is performed between the terminals using the network transmission line 2. Due to the operation up to this point, the faulty network transmission line 1
Is connected to the fault detection circuit 33 inside each automatic fault detection mechanism 3a, 3b, 3c, 3d.

From here, the failure detection operation is sequentially started in each automatic failure detection mechanism.

The fault detecting operation is performed in a predetermined order, that is, the above-mentioned fault detecting operation is performed by the automatic fault detecting mechanism 3a having the unique address "a". In this embodiment, since it is assumed that a cable failure has occurred between the terminals B and C, it is not possible to receive a response packet from the right side of the network, so it is determined that a failure has occurred in the right direction of the network. On the other hand, from the left side of the network, since the response packet from the bus monitoring processor is received, it is determined that there is no abnormality in the left side of the network transmission line, and the bus monitoring processor 0 is instructed to "the right side of the network transmission line 1". Occurrence of abnormality, no abnormality in the left direction "is notified. next,
The processing shifts to the automatic failure detection mechanism 3b (this shift is
After performing a similar failure detection operation (at a fixed timing), "the abnormality has occurred in the right direction of the network transmission line 1 and there is no abnormality in the left direction" is notified. Next, the processing shifts to the automatic failure detection mechanism 3c, and the bus monitoring processor 0 is notified of "no abnormality in the right direction of the network transmission line 1 and occurrence of abnormality in the left direction". Finally, the processing is shifted to the automatic failure detection mechanism 3d and the same failure detection operation is executed. Here, since the terminal D is the end terminal, the network transmission line is normally artificially terminated,
Since the response packet cannot be received from the right side of the network, “After executing termination control for the right side of the network transmission line 1, the bus monitoring processor was instructed,” An error occurred in the right direction of the network transmission line 1, in the left direction. Also occurs. ” As described above, the bus monitoring processor refers to the notification content from each automatic failure detection mechanism connected to the network, outputs an abnormality notification indicating that a cable failure has occurred between the terminals B and C, and processes it. To finish.

[0023]

As described above, the automatic fault detection system according to the present invention switches from the fault transmission line side to another network transmission line even when a cable fault such as a cable disconnection occurs during data communication. Later, by automatically searching for the location of the failure,
There is an effect that the failure occurrence location can be efficiently detected without degrading the availability of the system.

[Brief description of drawings]

FIG. 1 is a system block diagram showing an embodiment of the present invention.

2 is a block diagram showing the automatic failure detection mechanism of FIG. 1. FIG.

FIG. 3 is a block diagram showing the connector of FIG.

[Explanation of symbols]

 0 bus monitoring processor 1 network transmission line (1 system) 2 network transmission line (2 systems) 3a to 3d automatic failure detection mechanism A to D terminal 31 connector (1 system) 32 connector (2 systems) 33 failure detection circuit 34 network interface Circuit 35 Switching circuit 301 CPU 302 Packet transmission / reception circuit 303 Address table 304 Address detection circuit 305 Decoding circuit 306 Control circuit 311 Termination circuit 312 Termination circuit 313 Switching circuit 314 Switching circuit

Claims (2)

(57) [Claims] 1. An automatic failure detection system for automatically detecting a cable failure, such as a wire break, which has occurred on a network transmission line of an active system in a two-system bus network of an active system and a non-active system which accommodates a plurality of terminal devices, A bus which is connected to the two network transmission lines and outputs an analysis result when the cable failure of the working network transmission line is detected and an emergency packet is broadcast through the protection network transmission line and the test information is received. When the emergency packet is received from the non-operation system network transmission line between the monitoring processor and the two-system network transmission line and each of the terminal devices, the non-operation system network transmission line is subordinated as a new operation network transmission line. The connection position of itself in the network transmission line connected to the terminal device of According to the above, the operational network transmission line is individually tested from the self-connection position to the left and right according to a predetermined algorithm, and the test result is output as the test information through the new operational network transmission line. An automatic fault detection system comprising an automatic fault detection mechanism. 2. The automatic failure detection mechanism individually pulls in the first information line and the second information line, the third information line and the fourth information line, and the two-system network transmission lines. A first connector which is two connectors and has a connection function with the first information line according to a first instruction for the working network transmission line, and a termination function for each of the left and right directions, and the non-connector. A second connector having a function of connecting to the second information line according to a second instruction for the operation network transmission line, and a termination function for each of the left and right directions, the first information line and the A switching circuit that exclusively connects a second information line, the third information line, and the fourth information line to each other in response to a switching instruction, and a signal of the operating system network transmission line to the first circuit. Connector, said first A network interface circuit for relaying to the terminal device via the information line and the third information line, and the second connector, the second information line and the fourth information line from the non-operation system network transmission line. When the emergency packet is received via the switching circuit, the first information line and the fourth information line are simultaneously connected to the second information line and the third information line, respectively, and then the network transmission line is connected. In the operation system network transmission line at a predetermined time according to the connection position of the mechanism itself in the above, using the terminating function of the first connector via the first information line and the fourth information line. Based on a predetermined test algorithm, the left and right of the operational network transmission line are individually tested, and the second information line and the fourth information line are connected via the switching circuit. Claim, characterized in that they are composed of fault detection circuit for outputting through the second connector wherein the non-active network transmission path through as the test information the test results after continued 1
The described automatic fault detection system.