JPH04207338A - Transmission line changeover system at fault of multi-address communication - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to abnormality detection of a transmission line in a network system that performs broadcast communication, switching of the transmission line, and a method for realizing the same.

[Conventional technology]

The conventional transmission line abnormality detection method is: - A specific management node and a plurality of normal nodes are connected to the transmission line, and the management node has a monitoring program that communicates with the life/death monitoring table for the number of normal nodes and the normal nodes. The normal nodes are equipped with life/death monitoring tables and survival response programs for the number of normal nodes, and regular survival patrols are carried out between the management node and each normal node using dedicated lines. At the time of detection, failure information was broadcasted to other normal nodes all at once.

Note that Japanese Patent Application Laid-Open No. 2-60340 is a related example of this type of transmission path abnormality detection method.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into account backup and expandability in the event of a management node failure, and has problems in that it is difficult to detect failures in the event of a management node failure, and it is difficult to connect a dedicated line when adding nodes.

An object of the present invention is to improve reliability and reduce costs by having all nodes serve as management nodes and eliminating the need for a specific management node. Furthermore, by using only broadcast communication for inter-node communication (i), there is no need to connect a dedicated line, and scalability when adding nodes is improved.

[Means to solve the problem]

In order to achieve the above objective, each node is equipped with a table for monitoring the life/death status of all nodes, a program for sending survival reports, and a program for receiving survival reports and switching transmission paths according to transmission path switching instructions. It is something that

Furthermore, a program for recognizing the death of another node and a program for detecting transmission path abnormalities and transmitting a survival report including a transmission path switching instruction are provided.

[Effect]

The survival report sending program is activated at regular intervals as long as the own node is alive, creates a survival report message, and broadcasts the message to other nodes. The survival report reception program is started every time a survival report message is column-named, takes in the corresponding message, sets the part to the corresponding No. 1 in the node life/death monitoring table to raw, and further, if there is an instruction to switch the transmission path, Switch the transmission line according to the instructions. The configuration control program is activated at regular intervals as long as the own node is alive, and subtracts the remaining survival time in the node life/death monitoring table. If the remaining survival time becomes zero, the configuration control program uses the slave transmission path to Broadcast notification of death recognition message. The death recognition receiving program is started every time a death recognition message arrives, takes in the message, and if the death recognition node is another node, sets the node section in the node life/death monitoring table to dead. In addition, if the death recognition node is the own node, it is assumed that the main transmission line is abnormal, the transmission line is switched from the main transmission line to the slave transmission line, and a survival report message containing a transmission line switching instruction is sent to the transmission line. report. With these, it is possible to detect an abnormality in the transmission line and to switch the transmission line.

Furthermore, it has two live/dead monitoring tables for all nodes, one for the main transmission line and one for the slave transmission line, and broadcasts the survival report to both transmission lines at regular intervals. When a death is detected, the status of the node for the slave transmission line is determined, and if it is normal, it is assumed that there is an error in the main transmission line, and the transmission line is switched, thereby detecting a transmission line error during broadcast communication and switching the transmission line. can be done quickly.

Further, when an abnormality is detected in another node, the broadcast communication message is saved in a file, and the saved message is sent to the node when the node returns to normal, thereby preventing loss of the broadcast communication message when the node is abnormal.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 3 to 12.

FIG. 3 shows the format of the node life/death monitoring table created and updated at each node.

A unique integer number starting from 1 (this number is referred to as a node number) is assigned to all nodes that make up the network. The node life/death monitoring table is composed of elements from No. 1 to No. 1 to the maximum node number.

Each node also has a live/dead flag 1 indicating the live/dead status of the node.
02. and remaining survival time 1 indicating the remaining survival time of the node.
Consists of 03.

FIG. 4 shows a data format on a transmission path used when reporting survival according to the present invention. The data on the transmission path 2J- is a control section 121 representing the nature and attributes of the data, the originating node number, the destination node number 113, the initial value of the remaining survival time of the originating node 114. and a switching transmission line number for switching the transmission line when a death recognition message is received even though the node is alive, it is assumed that the transmission line is abnormal.

FIG. 5 shows the format of a death recognition message on a transmission path used when recognizing the death of a node in the configuration control program of the present invention. The data on the transmission path is controlled by a control unit 1221 that indicates the nature and attributes of the data, and a source node number 1 that indicates the source node number.
23, death recognition node number] 24.

FIG. 6 shows flowcharts 1 to 1 of the configuration control program for each node.

First, in order to process all nodes for 1 minute, initialize the processing node number in the node life/death monitoring table (], 31). Subtract the survival time of the node in the node life/death monitoring table indicated by the L processing node number (1, 32). . Here, if the remaining survival time is O, the next process is performed, and if the remaining survival time is O (133), the node part of the node life/death monitoring table is set to death (134). Next, if there is a slave transmission line (135), a node death recognition message is broadcasted using the slave transmission line (136). Finally, it is determined whether the processing of all nodes has been completed (137),
If the end is r, the processing node number in the node life/death monitoring table is updated (1, 38).

FIG. 7 is a flowchart of the survival report receiving program for each No. 1-. This program is activated by the operating system's attention interrupt mechanism each time a survival report message arrives from the transmission path.

This program first includes the survival alert message (]
, 4. ], ), No [-Set the node part of the life/death monitoring table to raw (1,42')L, and then set the remaining live tile l of the life/death monitoring table to No 1 with the initial value of the remaining cow survival time in the message. Set (143). Next, the switching transmission line number is written in the message as (14, 4), (
The transmission path is switched according to the number (145).

FIG. 8 is a flowchart of the death recognition reception program of each node.

This program is activated by the operating system's attention interrupt mechanism each time a death recognition message arrives from the transmission line. This program first takes in a death recognition message (151), determines whether the death recognition node in the message is the own node (15.2), and if it is a node, sets the node part in the node life/death monitoring table to death (155). ), if it is the own node, it is assumed that the main transmission line is faulty and the transmission line is switched from the main transmission line to the slave transmission line (15
3) Furthermore, a survival report message containing a transmission path switching instruction is broadcasted to the transmission path (154).

FIG. 9 is a flowchart of the survival report sending program for each node.

This program is activated at regular intervals by the operating system's periodic activation mechanism.

This program creates the survival report message shown in Figure 4 (161) and broadcasts the message to the transmission line (161).
162) Do.

FIG. 10 shows an embodiment of the transmission path switching method in the event of an abnormality in broadcast communication according to the present invention.

In a network system consisting of a main transmission line 3 and a slave transmission line 4 for broadcast communication, and two nodes 1 and 2 connected to both transmission lines, each of the nine nodes has node life/death information for all nodes. Monitoring table 12゜22, survival report sending program 16.26, and survival report receiving program 14.24
and a death recognition reception program 15, 25, and a configuration control program 15, 21, and each node's survival report sending program 16, 26 broadcasts the survival report message at regular intervals. Survival report receiving program for each node 14. ．． 24 sets the node portion of the node life/death monitoring table 12.22 to live every time a survival report message arrives. Furthermore, the configuration control program for each node]
, , 1 , 2.1- is a node life/death monitoring table at regular intervals of i1], 2. ．． Monitor 22.

Normally, the user's message sending program J9 uses the main transmission line 3 to perform broadcast notification, which is received by the user's message receiving program 29 of other nodes as necessary.

Now, assuming that a failure has occurred in the main transmission line 3, survival report messages from other nodes will no longer arrive. The configuration control program 1 which is running at regular intervals detects this by monitoring the node life/death monitoring table 12. Here, the configuration control program 1 broadcasts a node death recognition message using the slave transmission path. A death recognition message is received, and the death recognition reception program 25 recognizes that other nodes are dead even though the own node is alive.
It is determined that this is a fault in the main transmission line 2, the transmission line is switched from the Ji transmission line to the slave transmission line, and a survival report message of its own node containing a transmission line switching instruction is broadcasted. When the survival report receiving program of another node receives an instruction to switch the transmission path, it switches the transmission path according to its ability.

This allows the user's message sending program ]S]
can perform broadcast notification using the slave transmission line 4.

According to this embodiment, it is possible to detect a transmission path abnormality and switch the transmission path during broadcast communication.

FIG. 11 shows an embodiment of the transmission line switching method in the event of an abnormality in broadcast communication according to the present invention, and compared to the embodiment shown in FIG. .

The embodiment shown in Figs. 3 and 1 has two node life/death monitoring tables, 12.22 for the main transmission line and 13.23 for the slave transmission line, for the configuration shown in Fig. 0, and sends a survival report. Program 16.26 broadcasts the survival report message to both the main transmission line 3 and the slave transmission line 4, and performs a configuration control program]
monitors the node life/death monitoring table 12.13, and the configuration control program 21 monitors the node life/death monitoring table 22.23.
& monitoring, and when detecting the death of a node for the main transmission line, determines the status of the node for the slave transmission line5, and if it is normal, switches the transmission line to prevent transmission line errors during broadcast communication. It is possible to detect a signal and switch transmission paths at high speed.

FIG. 12 shows an embodiment of the transmission line switching system in the event of an abnormality in broadcast communication according to the present invention, and is a method for preventing loss of broadcast communication messages due to an abnormality in other nodes compared to the embodiment of FIG.

The embodiment shown in FIG. 12 has the configuration shown in FIG. 10, and saves it in the file 8 for retransmitting broadcast notification messages to abnormal nodes and the file 8 for retransmitting broadcast notification messages while intercepting them. , When a node recovers from an error 1.: By arranging a message retransmission program 17 that collectively transmits the messages in the retransmission file 18, it is possible to prevent the loss of broadcast communication messages when other nodes are abnormal.1 Furthermore, FIG. By adopting this embodiment, it is possible to detect abnormalities in transmission lines and switch transmission lines at high speed, thereby making it possible to construct a more reliable network system.

Further, if the embodiment shown in FIG. 12 is adopted, it is possible to prevent the loss of broadcast communication messages when other nodes are abnormal, thereby making it possible to construct an even more reliable one-work system.

〔Effect of the invention〕

According to the present invention, it is possible to detect abnormalities in the transmission path and to switch the transmission path, so it is possible to improve the reliability of the network system that performs the same reporting. Furthermore, since the abnormality detection method for the transmission path and the switching of the transmission path are all performed using the broadcast communication method, there is no need to be aware of specific nodes, and expandability is easy. Further, by making each node have a homogeneous configuration, a specific monitoring node is not required, and a highly reliable and low-cost system can be constructed.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a transmission line switching method in the event of an abnormality in broadcast communication according to an embodiment of the present invention, Fig. 2 is a block diagram of a conventional transmission line abnormality detection method, and Fig. 3 is an explanation of a node life/death monitoring table. 4 is an explanatory diagram of the survival report message format of transmission g-1-, FIG. 5 is an explanatory diagram of the death recognition message format on the transmission path, FIG. 6 is a processing flowchart of the configuration control program, and FIG. FIG. 8 is a processing flowchart of the survival report reception program, FIG. 9 is a processing flowchart of the survival report transmission program, and FIG. 10 is a flowchart of the death recognition reception program.
The figure is a block diagram of the second embodiment of the invention, and FIG. 12 is a flowchart of the third embodiment of the invention. 101 Node life/death monitoring table, 111...survival report message format,] 1. Configuration control program, 14.
...Survival report reception program, 16..Survival report transmission program.

Claims (1)

[Claims] 1. In a network system consisting of a main transmission path for broadcast communication, a secondary transmission path, and a plurality of nodes connected to both transmission paths, each of the nodes has a A life/death monitoring table, a survival report sending program, a survival report receiving program, a death recognition receiving program, and a configuration control program are provided, and mutual life/death monitoring of the nodes is performed while broadcasting survival reports at regular intervals, and death recognition of the nodes is performed. Sometimes, the death of the corresponding node is broadcasted using the slave transmission path, and the node that receives the notification of death recognition considers the transmission path abnormal and determines whether the node is still alive after switching the transmission path. A transmission path switching method in the event of a broadcast communication abnormality, characterized in that a broadcast notification of a report and a transmission path switching instruction is made, and the node receiving the notification restores the corresponding node to survival and switches the transmission path according to the notification. . 2. In claim 1, the life/death monitoring table for all nodes is divided into two parts, one for the main transmission line and one for the slave transmission line, and the survival report is broadcasted to both transmission lines at regular intervals, and the main system When the death of a node for a transmission line is detected, the status of the corresponding node for the slave transmission line is determined. Transmission line switching method when a broadcast communication error occurs. 3. In claim 1, when an abnormality is detected in another node, the broadcast communication data is saved in a file, and when the corresponding node returns to normal, the broadcast communication message is sent to the corresponding node. Loss prevention method.