JPS63299423A - System for relieving fault in loop shape transmission processing system - Google Patents

Abstract

PURPOSE:To rapidly form a new loop automatically, by setting a state at a looping back state while the disconnection of input is continued when the input disconnection of either signal inputs from a main or a sub transmission line is detected, and sending an abnormality signal to the high-order side of the transmission line relating to the detection of the disconnection via the transmission line on the other side. CONSTITUTION:The titlted system is constituted so that it is assumed that a fault is generated in a high-order side transmitter on the main transmission line or the main transmission between the transmitter when the input disconnection of a signal from the main transmission line is generated, and a signal on the sub transmission line from a main/sub folding circuit 17 can be outputted to a low-order side transmitter on the main transmission line via a sub/main folding circuit 15, a signal processing part 12, a signal switching circuit 18, and the main transmission line (looping back state). Simultaneously the abnormality signal is outputted from the signal switching circuit 14 to the high-order side transmitter on the main transmission line via the sub transmission line. Also, when the abnormality signal is inputted by the main transmission line, the signal from the main/sub folding circuit 17 is outputted from the signal switching circuit 14 as it is onto the sub transmission line.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a fault relief method in a loop transmission processing system in which transmission devices are connected by duplicated loop transmission paths, and in particular, The present invention relates to a fault relief method that can quickly deal with a fault in the case where a fault occurs in a transmission path, and also facilitates recovery after the fault is removed.

[Prior Art] Fig. 5 shows an outline of the configuration of a loop-shaped transmission processing system including five transmission devices, and in this case, the signal transmission directions of master station 1 and remote stations 2 to 5 are opposite to each other. It is connected by main transmission lines A-E and sub-transmission lines A' to E'.

In this case, the master station 1 has the function of uniformly managing signal transmission in the entire system, and normally sends and receives signals to and from each remote station 2 to 5 via the main transmission path A-E. It has become. In addition, sub-transmission lines A' to E'
In preparation for a failure, a signal similar to the signal on the main transmission line A-E is transmitted from the master station 1 in the opposite direction.

Incidentally, automatic loopback processing and automatic master/sub switching processing have become common as methods for handling failures in this type of system, as described in, for example, Japanese Patent Laid-Open No. 57-72443. .

[Problems to be Solved by the Invention] In the above conventional technology, when the master station goes down, the functions are transferred to the remaining remote stations. Until the time of deputation,
Since data does not flow through the loop-shaped transmission path and each remote station detects disconnection and automatically performs loopback processing, it takes a long time to form a new loop. In addition, since no signals are sent to unused transmission lines in the loopback state, it is not possible to automatically restore the double loop when a failure is recovered or when adding equipment. It has become a thing. Furthermore, there are some problems with the method of determining the remote station that will act on behalf of the system.

The purpose of the present invention is to enable a new loop transmission path to be formed immediately when a failure occurs in a transmission device or a loop transmission path, and to automatically create a new loop transmission path even when adding a transmission device or recovering from a failure.
Another object of the present invention is to provide a fault relief method in a loop transmission processing system that can quickly restore the double loop configuration.

[Means for solving the problem] The above purpose is to solve the problem in each transmission device that constitutes a loop transmission processing system, when a disconnection of either one of the signal inputs from the main transmission line or the sub transmission line is detected. In addition to taking a loopback state while the disconnection continues,
An abnormal signal is sent to the upper side of the transmission path related to the disconnection detection via the other transmission path, and if the abnormal signal is received and detected from any of the main and sub transmission paths, the abnormal signal is sent. This is achieved by continuing to send signals to the source and entering a loopback state while an abnormal signal is detected.

In addition, regarding transmission equipment that performs the functions of the master station,
Regardless of whether or not a failure actually occurs in the master station, it is put into a loopback state due to some kind of failure2.
This is achieved by the one among the two transmission devices that detects a predetermined signal input state operating as a master station from then on.

[Operation] A transmission device that determines that the input signal is disconnected due to a failure in either the main transmission line, the sub-transmission line, or any transmission device is placed in an automatic loopback state, and a notification is sent to the upper level to indicate that the signal is not being input normally. It is designed to continuously send an abnormality signal to the other transmission line in order to notify the side transmission device.

The upper transmission device that received the abnormal signal knows that the transmitted signal is not received by the lower transmission device, and as a result, it is placed in a loopback state even though it sends the original signal.

As a result, a new loop is formed, but in this state, the signal that should originally be transmitted from the upper transmission device is
In addition, since the lower-level transmission equipment continues to send abnormal signals to the transmission line for each other to transmit, a normal signal will be input to the lower-level transmission equipment when the fault is restored. The lower transmission device automatically releases the loopback state, stops sending the abnormal signal to the upper transmission device, and then sends out the signal that should have been transmitted. This also releases the loopback state in the higher-order transmission device, making it possible to easily restore the double loop configuration.

By the way, regarding the substitution of the function of the master station, if the input from one of the transmission lines 1 of the double loop transmission line, for example, the main transmission line, is cut off, or if an abnormal signal is input from that transmission line, the transmission device becomes the master station. By specifying that the station will act as a substitute, if a failure occurs in the master station, a transmission device that will act as the master station will be immediately determined, making it possible to handle the failure. Not only failures in the master station but also failures in other transmission equipment and disconnection of transmission lines are handled using the same procedure, so a new double loop is quickly formed in the event of a failure, and failure recovery is possible. Sometimes the original double loop can be quickly restored.

Depending on such procedural processing, it becomes easy to add or delete a transmission device from the system, as will be described later.

[Example] The present invention will be explained below with reference to FIGS. 1 to 4.

First, the main structure of a transmission device as a master station and a remote station according to the present invention will be described. FIG. 1 shows an example of the structure. As shown in the figure, in normal times, the signal from the upper transmission device via the main transmission line is obtained as a received signal via the sub/main folding circuit 15, and this received signal requires the signal processing section 12. The transmitted signal is inserted in accordance with the signal and is outputted to the lower-order transmission device via the signal switching circuit 18 and the main transmission path.

On the other hand, the signals from the upper-level transmission device via the sub-transmission line are transmitted as they are to the lower-level transmission device via the main/sub return circuit 17, the signal switching circuit 14, and the sub-transmission line. There is. However, the above-mentioned upper side and lower side are based on the flow of signals, and mean a signal transmission source and a signal transmission destination, respectively.

Now, during normal times, signals flow as described above, but if a failure occurs in an adjacent transmission device or the transmission path between them, the flow is turned back to a predetermined point, Further, an abnormal signal is outputted onto a predetermined transmission path.

That is, the input states of the signals from the main and sub-transmission lines are monitored by the input monitoring circuits 13 and 16, respectively, and the signal states include a normal signal input state, an abnormal signal input state, and an input cut-off state. There are three possibilities. If the input signal from the main transmission path is cut off, it is assumed that a failure has occurred in the upper transmission device on the main transmission path or the main transmission path between it, and the main/sub return circuit 17 The signal on the sub-transmission path is outputted to the lower transmission device on the main transmission path via the sub/main folding circuit 15, the signal processing section 12, the signal switching circuit 18, and the main transmission path. Yes (loopback state).

At the same time, an abnormal signal is outputted from the signal switching circuit 14 via the sub-transmission line to the higher-order transmission device on the main transmission line. In addition, if an abnormal signal is input through the main transmission path, it is assumed that a fault has occurred in the sub-transmission path between the main transmission path and the upper transmission device, and the same loop as in the previous case is established. However, the signal switching circuit 14 continues to output the signal from the main/sub folding circuit 17 onto the sub transmission path.

On the other hand, if the input signal from the sub-transmission path is cut off, it is assumed that a failure has occurred in the upper transmission device on the sub-transmission path or in the sub-transmission path between it, and the signal processing unit 12 The signal on the main transmission path is looped back to the upper transmission device on the main transmission path via the main/sub return circuit 17, the signal switching circuit 14, and the sub transmission path (loopback state). . At the same time, an abnormal signal is outputted from the signal switching circuit 18 via the main transmission path to the upper transmission device on the main transmission path. In addition, if an abnormal signal is input from the sub-transmission path, it is assumed that a fault has occurred in the main transmission path between the lower transmission device on the main transmission path, and the signal processing unit 12 The signal on the main transmission path is looped back to the upper transmission device on the main transmission path via the main/sub loopback circuit 17 and the signal switching circuit 14, and at the same time, the signal on the main transmission path from the signal processing section 12 is sent back from the signal switching circuit 18. The signal is output as is. Note that the reference numeral 11 in FIG.
, 17 is shown.

The configuration and operation of the main parts of the transmission equipment have been explained above, but below we will explain the operation of the system using a specific example of a failure. This shows a state where is not input. As mentioned above, master station 1 and remote stations 2 to 5
An input monitoring circuit is provided for each input from the main transmission path and the sub transmission path, and loop control is generally performed based on the monitoring results from this input monitoring circuit. Now, in the case of the fault shown in Fig. 2, the input monitoring circuit corresponding to the main transmission line at remote station 3 detects a disconnection in transmission line B, and remote station 3 performs fault processing based on the detection result. Not knowing that line B is disconnected, the signal continues to be sent to transmission line B. In such a case, conventionally, the remote station 3 would loop back the signal on the sub-transmission line C' onto the main transmission line C as a troubleshooting measure, and at the same time stop sending the signal to the sub-transmission line B'. It is. As a result, the input monitoring circuit corresponding to the sub-transmission line at remote station 2 detects the disconnection of transmission line B', and remote station 2 also performs loopback processing and stops sending signals onto main transmission line B. This is what I was looking for.

By handling such failures, a new transmission loop A-A' is created.
-E'-D'-C'-C-D-E is formed, but since no signals are sent to main transmission line B and sub-transmission line B', the failure of main transmission line B is restored. The problem was that even if it did, it could not automatically return to the original normal loop state. If a transmission device is added to or removed from the system by temporarily disconnecting the transmission line, for the same reason, a problem may occur in which the device cannot automatically enter or leave the system. This is what I was looking for.

However, in the present invention, when the remote station 3 detects a disconnection of the main transmission line B, the remote station 3 returns the signal from the sub-transmission line C' and sends it to the main transmission line C. In order to notify the remote station 2 that the signal from the sub-transmission line B' is not being input normally, an abnormal signal is continuously sent to the sub-transmission line B'.

Since the abnormal signal can be distinguished from a normal signal by the input monitoring circuit, the remote station 2 that received the abnormal signal knows that the signal sent to the main transmission path B is not received normally by the remote station 3. At remote station 2, the signal from main transmission line A is turned back within the station and sent to sub-transmission line A', and the signal from main transmission line A continues to be sent to main transmission line B as before in preparation for recovery. It becomes. As a result, a new loop A-A'-E'-D'-C'-C-D-E is formed as in the conventional case, but the difference is in the operation at the time of restoration. When main transmission line B is restored, the signal sent by remote station 2 is again input to remote station 3 via main transmission line B, and the input monitoring circuit in remote station 3 determines that the input is normal and continues until then. The folding that had been done is canceled, and the signal from sub-transmission line C' is transferred to sub-transmission line B'.
It is about to be sent out again. As a result, the loopback is canceled at the remote station 2 as well, and the normal double loop shown in FIG. 5 can be automatically restored. By the way, main transmission line B, sub transmission line B
If both the remote stations 2 and 3 are disconnected at the same time, both the remote stations 2 and 3 are placed in a loopback state, and abnormal signals are sent to both the main transmission line B and the sub-transmission line B'. However, for example, if main transmission line B is restored first, remote station 3 will receive an abnormal signal from the input cut-off state and will send the signal from sub-transmission line C' to sub-transmission line B'. , sub-transmission line B
'At the time of recovery, the signal from sub-transmission path C' is input to remote station 2, so the loopback state at remote station 2 is canceled, and the loopback state at remote station 3 is also canceled after that, and the duplex It becomes possible to automatically restore the loop state.

By the way, conventionally, in the case of a failure in the transmission line or remote station, master station 1 remains as the master station (however, the signal on sub-transmission line A' must be passed to sub-transmission line E'). However, if the master station 1 itself fails, one of the remote stations 2 to 5 will take over the functions of the master station 1.The failure handling method differs depending on where the failure occurs. There are, but
The logic for determining the remote station that will act on behalf of the master station 1 is complex, and it takes a lot of time to make that determination.

Figure 3 shows that master station 1 has failed, and remote stations 2 and 5 are unable to receive signals from master station 1 and are placed in a loopback state, creating a new loop B-C-D-D.
It shows a state in which '-C'-B' is formed. In this case, the remote station 2.5 knows that a fault has occurred based on information from the input monitoring circuit, but it is simply the case that the main transmission line A,
It is not possible to immediately determine whether there is a break in the sub-transmission line E' or whether the master station is absent due to a failure in the master station 1.
It takes a lot of time to make this determination, and therefore, there is a problem in that it takes time for any of the remote stations 2 to 5 to take over the functions of the master station 1.

However, in the case of the present invention, regardless of whether a failure has actually occurred in the master station 1, for example, when a signal input disconnection from the main transmission line (or a sub transmission line is also possible) or an abnormal signal input is detected. If it is stipulated that the master station 1 performs the functions of the master station 1, the problem of time-consuming troubleshooting can be solved. In this way, since the same rules can be used to deal with failures anywhere, control becomes simple, and by operating according to these rules, any remote station can act as the master station. Become. In other words, since the master station and remote stations can have the same configuration, it is possible to prevent partial failures from affecting the entire system, without having to create a duplex configuration for the master station to ensure high reliability. Reliability will be improved.

Finally, to explain the addition of a transmission device to the system, normally in a loop transmission processing system, the transmission device is connected in a duplex loop as shown in Figure 5. It is often possible to add a device or to remove a transmission device at an arbitrary location from the system. Up until now, operation of loop-shaped transmission processing systems has been temporarily stopped when adding or removing transmission equipment, but if possible, it is desirable to add or remove transmission equipment without stopping operation. . In the loop transmission processing system according to the present invention, it is easy to add or remove devices while the system is in operation.

For example, if we assume that a new transmission device 6 is added between the transmission devices 1 and 5 as shown in FIG.
, E' are once opened, and transmission lines F and F' are newly provided between the transmission devices 1 and 6. transmission line E,
By simultaneously opening E', the transmission device 1,
5 are both placed in a loopback state, but transmission device 1
will output an abnormal signal to the transmission path F', and the transmission device 5 will also output an abnormal signal to the transmission path E. In this state, a loop A-B-C-D-D'-C'-B'-A' is formed, and in this state, the transmission device 6 has transmission lines E, E', F, F. ' is connected and the power is turned on, an abnormal signal is input to the other party via the transmission device 6 which is still in the initial state, and this causes the other party to When a normal signal is sent to both, the loopback state is released. In the case of withdrawal, withdrawal is also possible while the system is in operation.

[Effects of the Invention] As explained above, according to the present invention, when a failure occurs in a transmission device or a transmission path, a new loop is not only quickly and automatically formed, but also a new loop can be quickly and automatically formed. There are four advantages in that a double loop can be automatically and quickly formed even during failure recovery.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the main part configuration of a transmission device according to the present invention,
FIG. 2 is a diagram for explaining the operation in the event of a main transmission line disconnection failure, FIG. 3 is a diagram for explaining the operation according to the present invention in the event of a master station failure, and FIG. 4 is a diagram for explaining the operation in the event of a failure in the main transmission line. FIG. 5 is a diagram illustrating an overview of the system configuration of the loop transmission processing system. 1...Master station, 2-6...Remote station, A-F.
...Main transmission line, A' to F'...Sub transmission line. Agent Patent Attorney Masami Akimoto (1 other person) 2
:2 Figure 4 Figure 5

Claims (1)

[Claims] 1. A fault relief method in a loop-shaped transmission processing system in which transmission devices are connected by loop-shaped main and sub-transmission paths in which the signal transmission directions are mutually reversed, wherein each of the transmission devices In this case, if a disconnection of either the signal input from the main or sub transmission line is detected,
While the disconnection continues, it enters a loopback state, and sends an abnormal signal to the upper side of the transmission path related to the disconnection detection via the other transmission path, while determining whether the abnormal signal is from the main or sub transmission path. 1. A fault recovery method in a loop transmission processing system, characterized in that when reception is detected by an abnormal signal, a loopback state is maintained while the abnormal signal is detected while continuing to send the signal to the abnormal signal transmission source. 2. A transmission device that detects an abnormal signal or signal input interruption from a predetermined main or sub transmission path will thereafter operate as a master station that manages the entire system. A fault relief method in a loop transmission processing system according to claim 1.