JPH03195146A - Monitoring and testing system for ring network - Google Patents

Abstract

PURPOSE:To execute the decision of a communication node with an instability fault while executing normal data communication by controlling the token counter of each communication node from a monitor test node. CONSTITUTION:A monitor test node 15 is provided to detect where the loss of the token is generated by the generation of the instability fault, and the operation of a taken counter 11 provided at each communication node 10 is controlled from the monitor test node 15. At each communication node 10, the value of the token counter 11 at the node itself is monitored corresponding to a command from the monitor test node 15 and transmitted to the test node 15. Thus, without exerting a strong influence upon a ring network system, a spot generating the instability fault can be detected.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a monitoring test method for a ring network in which communication nodes are connected in a ring and transmission rights are controlled by tokens.

The purpose of this paper is to provide a ring network monitoring test method that can detect the location of unstable failures without significantly affecting the operation of the ring network system.

A ring network is provided with a monitoring test node having a counter control frame creation means, a token counter and a count analysis means, and each communication node is provided with a token counter and a frame analysis means.

The monitoring test node sends out a token count control frame that instructs to start, stop, and read the operation of the token counter, and when each communication node detects the counter control frame, it starts the operation of its respective token counter. Start, stop, and read.

A token count frame is created and transmitted, and the monitoring test node is configured to receive the token count value of each communication node and analyze the location where an abnormality has occurred using the count analysis means.

[Industrial Application Field] The present invention relates to a ring network monitoring and testing system in which communication nodes are connected in a ring and transmission rights are controlled using tokens.

In recent years, ring networks in which communication nodes having data transmission and reception functions are connected in a ring shape have become widely used in communications such as LANs (local area networks).

This ring network system has a problem in that a failure occurring in just one communication node among the communication nodes connected to the ring is highly likely to spread to the entire ring network system.

To deal with this, methods have been used in the past to detect which communication node has failed, but it has not been possible to identify the communication node that is the cause of the failure depending on the nature of the failure.

[Conventional technology] FIG. 3 is a configuration diagram of a conventional ring network.

FIG. 4 is a configuration diagram of a conventional communication node.

As shown in Figure 3, in the ring network 3o, multiple communication nodes are connected in a ring shape through transmission paths, and data is sent and received between the nodes.In the case of Figure 0, only one transmission path is shown. However, there is also a ring network in which a ring with two transmission paths is provided to have a redundant configuration so as to be able to cope with failures and the like.

In such ring network communication, a widely used method is to use a communication right acquisition frame (called a token), and the communication node that acquires the token has the transmission right and sends this data to the ring network. Ori,
Such a ring is called a token passing ring.

In a token passing ring network (hereinafter simply referred to as ring network) system, among a large number of communication nodes connected to the ring network,
If a failure occurs in one communication node, there is a high possibility that the entire ring network system will be affected. Therefore, in a ring network system, when a failure occurs, it is required to isolate the failed communication node as quickly as possible. .

FIG. 4 is a block diagram of a conventional communication node equipped with means for performing fault isolation.

In FIG. 4, in the nine communication nodes 31, 32 is a ring interface (R, 1, F, ) receiving section, 33 is a data analysis section, 34 is a data delay section, 35 is a ring transmission control section,
36 is a node processing unit, 37 is a transmission data selector, 38
is a ring interface (R.

1, P, ) transmitter, 39 represents a bypass selector.

The communication node 31 receives frame-structured data from an adjacent node (on the right side of the figure) through a transmission path.

The contents are analyzed by the data analysis unit 33, and data addressed to the own node is input to the node processing unit 36, while received data (including data addressed to other nodes) is delayed by the data delay unit 34 and then sent to the transmission data selector 37. Enter. The transmission data selector 37 is controlled by the ring transmission control section 35, and the node processing section 36 is controlled by the data analysis section 3.
Adjacent nodes (located on the left side of the diagram) that are controlled according to the results of the analysis in step 3 and whose received data are not shown.
When the data is transferred to the data delay section 34, the selector 37 is switched to select the output of the data delay section 34.

Furthermore, when the data analysis section 33 detects a token, the node processing section 36 is notified and if data is to be transmitted from the node processing section 36, the ring transmission control section 35 is instructed to switch the selector 37 and the node processing section 36 is notified. Select the data to be output from.

The output of the transmission data selector 37 is transmitted from the ring interface transmission section 38 to the adjacent node via the bypass selector 39.

In such a node configuration, if a failure occurs,
As a first method, one node among the plurality of communication nodes 31 shown in FIG. 3 selects another communication node and sends a bypass formation command (for example,
In the communication node that received the command, the bypass selector 39 shown in FIG. Form a bypass route to an adjacent communication node. The second method is to put a certain communication node into a bypass state by two people. This disconnects this communication node from the ring network.

In this state, communication within the ring network is monitored, and if the ring network is restored without any abnormality occurring, it is determined that a failure has occurred in the bypassed communication node, and if an abnormality still occurs, then , other communication nodes are assumed to be at fault, and the other communication nodes are bypassed in turn to investigate and determine.

[The invention is trying to solve the problem! ] According to the above-mentioned conventional method, it is necessary to put the nine communication nodes into a bypass state one by one and check whether or not to restore the system, so there is a problem that a large amount of time is required when the number of nine communication nodes increases.

In addition, for unstable failures that occur instantaneously and from time to time, such as a worsening of the bit error rate, we do not monitor for a certain period of time whether or not bit errors occur after forming a bypass. Therefore, in order to detect such a failure in a ring network consisting of a large number of communication nodes, it is necessary to conduct an extremely long test, which may impede the operation of the ring network system. Therefore, there was a problem that it was difficult to implement.

SUMMARY OF THE INVENTION An object of the present invention is to provide a ring network monitoring test method that can detect the location where an unstable failure occurs without significantly affecting the operation of the ring network system.

The location of the abnormality is analyzed based on the token count value sent from each communication node.

1.Means to solve the problem] FIG. 1 is a diagram showing the principle configuration of the present invention.

In FIG. 1, 10 is a communication node, 11 is a token counter, 12 is a token count frame creating means, 1
3 is a node processing unit that processes transmitted/received data and tokens, 14 is a frame analysis means, 15 is a monitoring test node, 16 is a token counter, 17 is a counter control frame creation means, 1B is a count analysis means, 19 represents a transmission path forming a ring.

The present invention is used to detect where loss of tokens occurs due to the occurrence of instability failures.

A monitoring test node is provided, and the monitoring test node controls the operation of the token counter provided in each communication node, and each communication node directs the value of its own token counter to the monitoring test node in response to instructions from the monitoring test node. and send. [Operation] In the monitoring test node 15, when an instruction to start a monitoring test is input, the counter control frame creation means 17 operates to create a frame containing an instruction to reset the token counter and start operation. All communication nodes 10 are made to send it. At this time, the token counter 16 in the monitoring test node 15 is also reset, and subsequent token counting operations are started. In each communication node, the frame received from the transmission path 19 is identified by the frame analysis means 14.

When it is detected that the frame is for resetting the token counter and starting the operation, the token counter 11 is reset and the operation is started.

The token counters of each communication node 10 and monitoring test node 15 count each time a token circulating in the ring network is detected. Since tokens always circulate through each node in the ring, under normal conditions, the same number of tokens can be detected at each node.

When a stop instruction is input to the counter control frame creation means 17 after a predetermined time, the counter control frame creation means 1
7 creates and transmits a frame instructing to stop the token counter and read the count value. When this frame is detected by the frame analysis means 14 of all other communication nodes 10, the operation of the token counter is stopped, the count value is read out, and the token count frame creation means 1
Supply to 2. Token count frame creation means 12
is activated when the frame analysis means 14 detects this frame, and creates and transmits a frame (addressed to the monitoring test node) containing the input count value of the token counter.

The monitoring test node 15 extracts the count value from the frame sent from each node through the transmission line 19, compares the count value of the token counter 16 of its own node with the count value of each communication node, and determines the count value. detects the location where the values differ and generates an output indicating the node where the change occurred.

In this way, by counting the tokens of each communication node during normal communication operation for a predetermined period of time using a token counter, and analyzing the counted value at the monitoring test node, it is possible to estimate the failure location where the token was lost due to the occurrence of an unstable failure. I can do it with my power. Since the monitoring time by this token counter is executed in parallel with the normal communication operation of the ring network, it can be monitored for any necessary time, and it becomes easy to detect the location where an unstable failure occurs.

[Example] FIG. 2 is a configuration diagram of the embodiment.

In FIG. 2, 20 is a communication node, 21 is a transmission path, and 22
represents a monitoring test node.

The configuration and operation of the embodiment will be explained.

In the monitoring test node 22, normally the frame received by the ring interface receiving unit 223 is sent to the data delaying unit 22.
5. )-Ring interface transmitter 222 via selector 227 for playback and selector 224 for frame
The signal is transmitted from the bypass selector 221 to the transmission path.

The token loss detection unit 229 monitors whether the token does not appear for a certain period of time, and when loss is detected, the token regeneration unit 2
28 to generate a token, and at the same time switch the token reproduction selector 227 to select the reproduced token from the token reproduction unit 228 and select the frame selector 224.
Output from.

The token counter control frame creation unit 230 is the activation unit 2
31, generates a token counter control frame, generates a control signal to switch the frame selector 224, switches the frame selector 224, and sends out the created token counter control frame.

The starting unit 231 is driven by manual input by an operator or automatic input (an abnormality detection signal, a timer signal, etc.). When starting monitoring by the token counter, the token counter control frame creation unit 230 creates a token counter reset/start (resets the token counter and starts counting from that state) frame, and transmits this frame. When the count value of the token counter is collected and analyzed after a predetermined period of time has elapsed,
A token counter stop lead frame for stopping the operation of the counter and reading the count value is created and sent.

The Token Counter Control Frame has a format similar to 2 normal frames, with a start flag, address field, control field, and data.

Consists of end flag, etc., token counter reset,
The start and token counter stop read frames are indicated by control fields therein. Note that the display of the frame representing the token is represented by some bits of the control field.

In the communication node 20, data of the frame received by the normal ring interface receiving unit 203 is sent to the data analysis unit 2.
If the token is detected, the ring transmission control unit 209 is notified that the transmission right can be acquired. At this time, when there is a transmission request from the node processing unit 212, the transmission data selector 204 is switched and the transmission data output from the node processing unit 212 is transmitted from the ring interface transmission unit 202 via the frame selector 21181') transmission data selector 204. to be done.

Furthermore, frames addressed to the own node are detected by the data analysis unit 207 and passed through the frame analysis unit 208 to the node processing unit 21.
Enter 2. Frames addressed to the own node and frames addressed to other nodes are input to the transmission data selector 204 via the data delay section 205, and are transmitted from the ring interface transmission section 202 through there.

According to the present invention, each communication node 20 is provided with a token counter 206 that counts the tokens passing through its own node, and the token counter control frame sent from the monitoring test node 22 is analyzed by a frame analysis section 208. Further, a token count frame creation section 210 for transmitting the value of the token counter to the monitoring test node and a frame selector 211 for transmitting the token counter frame are provided.

To explain the operation of the monitoring test, when an unstable failure occurs on the ring network, such as data errors or token loss, which occur more frequently.

The token counter control frame creation unit 230 of the monitoring test node 22 starts up, first resets the token counter 226 in its own node, and creates a token counter reset start frame.

It is sent to all communication nodes via the frame selector 224 (the above frame address is made a global address).

Each communication node uses a frame analysis unit 2 to determine that the received frame is a token counter reset/start frame.
When analyzed at 08, the token counter 206 is reset, and thereafter the token counter 206 increments by "+1" each time a token passes through a communication node. Furthermore, the token counter 2.6 continues counting even if the count value overflows. This is because, under normal conditions, the token counters of all communication nodes and the token counters of the monitoring test nodes show exactly the same value.

Therefore, a 1 determination can be made by comparing the lower digits.

By continuing to count even if there is an overflow, there is no limit to the monitoring time and it is possible to deal with failures with a low error rate.

The monitoring test node 22 stops the token counter 226 within its own node after an arbitrary period of time.

The token counter control frame creation unit 230 creates a token counter stop frame.

It is sent to all communication nodes via the frame selector 224. In each communication node 20, when the frame analysis unit 208 analyzes that the received frame is a token counter stop/read frame, the token counter 2
06, and the token count frame creation unit 210
reads the count value of the token counter 206 at that time (stop status a) and creates a token count frame (with the destination address set to the monitoring test node 22),
Monitoring test node 22 via frame selector 211
Send to.

The monitoring test node 22 receives token count frames from all communication nodes, and the token count frame analysis unit 232 compares each token count value with the value of the token counter 226 of its own node. It is determined that the communication node (the closest side with respect to the sending side of the monitoring test node) is at fault.

Note that even if a token is lost, the token counter 226 of the monitoring test node 22 counts the token after being reproduced by the token reproducing unit 228, so it can be used as a reference value in this case.

The count value and analysis results input to the token count frame analysis section 232 can be displayed on the display section 233.

In this way, it is possible to isolate the location of an unstable fault without affecting normal communication.

[Effects of the Invention] According to the present invention, it is possible to determine a communication node that has experienced an unstable failure in a ring network while performing normal data communication without any influence.

19: Transmission line

Claims (1)

[Claims] In a ring network in which communication nodes are connected in a ring shape and transmission rights are controlled by tokens, the ring network includes a counter control frame creation means (17), a token counter (16), and a count analysis means (18).
A monitoring test node (15) is provided, and each communication node (10) is provided with a token counter (11),
It is equipped with a frame analysis means (14) and a token count frame creation means (12), and the monitoring test node sends out a counter control frame instructing to start, stop, and read the operation of the token counter, and each communication node uses the above-mentioned counter. When a control frame is detected, each token counter starts and stops operating.
A ring network monitoring test characterized in that a token count frame is read, a token count frame is created and transmitted, and the monitoring test node receives the token count value of each communication node and analyzes the location where an abnormality occurs using a count analysis means. method.