JPH10164112A - System for controlling network configuration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a network consfiguration controlling system whereby a processing for constituting a network is simplified and executed at high speed. SOLUTION: Respective stations 1 and 2 detect a fault in the transmission path of an immediately upper stream, turning-back is executed by the stations 1 and 2 which detect the fault, a self-station number is reported to a master station 1 and the master station 1 gives an instruction to the stations 1 and 2 which have to execute the turning-back of an opposite side based on the reported station number. The master station 1 recognizes the station with the fault by a report so that the network is quickly re-constituted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network configuration control method for reconfiguring a network when a failure occurs in a loop type transmission system having a double transmission path, and in particular, to simplify and speed up network configuration processing. The present invention relates to a network configuration control method capable of performing the above.

[0002]

2. Description of the Related Art As shown in FIG. 5, a loop type transmission system, which is a transmission system used for factory automation (FA) and the like, conventionally uses a dual transmission line composed of transmission lines 7 and 8 to transmit a signal to a parent station 1. And a plurality of stations including child stations 2 are connected to form a double loop network. A transmission unit called a frame 3 is circulated through a transmission path, and each of the stations 1 and 2 transmits and receives data to and from this frame 3,
Communication between stations. A terminal (not shown) is connected to each station.
Data such as a signal and a voice signal based on the C standard are transmitted to and received from a station.

[0003] A frame 3 includes a frame header area 4 provided at the head for notifying the arrival of the frame,
And a time slot area 5 which is time-divided into a plurality of time slots. The stations 1 and 2 take in data from the terminals into the time slots, or send out the contents of the time slots to the terminals, so that data exchange between the stations 1 and 2 and the terminals and data transfer between the stations are performed.

Line setting information indicating various settings such as synchronous or asynchronous of a line connecting the stations 1 and 2 and a terminal, and network configuration information indicating a connection form of a transmission line are stored in a frame header area 4. The information can be transmitted by using the inter-station communication area 6 included in the master station 1 and the information is created by the parent station 1 by software and transmitted to the child station 2, so that the line setting and network configuration can be performed by the parent station 1. 1 can be software controlled.

[0005] The double transmission line is composed of a main transmission line 7 and a sub transmission line 8. In the example of FIG. 5, the main transmission line 7 is clockwise and the sub transmission line 8 is counterclockwise. Can be transmitted. Normally, the frame 3 is used using only the main transmission path 7.
Is orbiting.

In a conventional transmission system, when a failure occurs in a transmission line, a network is reconfigured by performing loopback between the master and slave systems in stations on both sides of the failure. I have.

FIG. 6 shows a loopback state. When a failure occurs in the transmission path, a loop network is formed by looping back from the master system to the slave system and from the slave system to the master system in the stations 1 and 2 sandwiching the failure location (marked by x). In order to perform this loopback, the parent station 1 detects the occurrence of a failure from a frame time-out, and issues a loopback command. The loopback command is transmitted from the parent station 1 to each of the child stations 2 via the subordinate transmission line 8. From the parent station 1, the child station 2 closest to the periphery of the subordinate (counterclockwise in FIG. 6) starts. If a frame from the slave system returns to the parent station 1 via the master system by this loopback, the main system transmission path 7
Therefore, the parent station 1 releases the loopback of the child station 2 and issues a loopback command to the next child station 2. In this way, when the slave stations 2 that perform loopback sequentially from the one near the slave system are changed, it becomes impossible to perform transmission by loopback when the failure includes the master transmission line 7. Become. In this way, the child station 2 immediately before the transmission becomes impossible is searched, and the network configuration is determined so that the child station 2 performs loopback.

[0008]

Since the search around the slave system is sequentially performed, if the number of stations increases, it takes time to complete the search, and it takes time to reconfigure the network.

An object of the present invention is to provide a network configuration control method that solves the above-mentioned problems and simplifies and speeds up the processing of the network configuration.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a dual loop network in which one master station and one or more slave stations are sequentially connected by a double transmission line. The frame is circulated through one transmission path, and each station communicates by transmitting and receiving data to and from this frame, and the other transmission path is configured to be able to communicate in the opposite direction, and the one transmission When a failure occurs in a path, in a network configuration control method of a transmission system in which the transmission path is looped back in the stations on both sides of the failure point and the network is reconfigured, each station can determine the failure of the transmission path immediately upstream. The station that has detected the failure performs loopback and notifies its own station number to the parent station. In which an instruction to the station to perform the opposite side of the wrapping.

Each station may detect a failure in the transmission line due to the disconnection of the carrier from the upstream of the station.

The parent station may detect a failure in the transmission line due to the inability to receive the circulated frame, and the returning station may transmit a frame for notifying the number in the reverse direction.

[0013] In the frame, an area for writing the number of the station performing the return may be provided.

[0014]

An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 shows an example of a transmission system to which the network configuration control method of the present invention is applied. In this transmission system, one parent station 1 and three child stations 2 are sequentially connected by a double transmission line including a main transmission line 7 and a sub transmission line 8 to form a loop network. Things.
In this transmission system, communication is normally performed using only the main transmission path 7 and the sub transmission path 8 is not used for communication. Therefore, in a normal loop in which there is no failure in the transmission path, a carrier signal flows through the main transmission path 7, and when the frame 3 is transmitted, data modulated on the carrier signal flows. The slave transmission line 8 is used for carrier detection. Therefore, during the normal loop, only the carrier signal always flows through the slave system.

According to the present invention, each station detects a fault in the transmission line immediately upstream, and the station which has detected the fault immediately returns and notifies the parent station 1 of the station number. An instruction is given to a station to be turned back on the opposite side based on the station number. In the present embodiment, each station detects a failure when the main carrier cannot be detected, and internally performs an operation of returning from the subordinate system to the main system by itself. The parent station 1 detects the occurrence of a failure due to the timeout of the frame 3 and performs a loopback process. Therefore, the condition under which the loop-back process is performed by software at the parent station 1 is when the frame 3 cannot be normally received at the parent station 1. Is no longer detectable.

The station numbers (hereinafter denoted by No) are No. 0 for the parent station 1 and No. 10, 11, and 12 for the child station 2 in a clockwise order.

Based on the network configuration control method of the present invention, as shown in FIG. 2, a return station number area 9 is provided as a dedicated area for writing the number of a station returning a transmission path in the frame header area 4. Is provided.

The outline of the loopback process will be described with reference to FIGS. 1, 3 and 4.

First, the return from the slave to the master, that is, the loopback of the slave will be described. In FIG. 1, it is assumed that a failure has occurred in the transmission path between the child station 2 of No. 10 and the child station 2 of No. 11. First, the child station 2 of No. 11 immediately downstream of the failure point
Detects the disconnection of the main carrier and turns the slave transmission line 8 back to the main transmission line 7 as shown by the dotted line in FIG. Therefore, the slave carrier flowing in the slave transmission line 8 reaches the slave station 2 of No. 12, so that the slave station 2 of No. 12 does not enter the loopback state.

On the other hand, the master station 1 determines that a failure has occurred in the transmission line and enters a loopback process because the state in which the circulated frame cannot be received continues and a timeout occurs. Therefore, the parent station 1 is connected to the slave transmission line 8.
Send out the frame in which the loop search command is written. This frame arrives at the child station 2 of No11. When the child station 2 of No. 11 detects the frame header, it writes its own station number “11” as the number of the subordinate loopback station in the return station number area 9 in the frame header area 4 and writes the frame into the main transmission path. Send out to 7. As a result, the content of the return station number area 9 changes from “blank” to “11”. The parent station 1 receiving this frame stores the contents of the return station number area 9 in a register such as a memory.

Next, return from the master system to the slave system, that is, loopback of the master system will be described with reference to FIGS.
If the slave station No. 0 has the slave loopback station number “11” written in the return station number area 9, the station located before the child station 2 No. 11 when viewed around the main system, ie, No. 10
Is instructed to turn the opposite side back. That is, a loopback command around the main system is written in the communication area 6 between the stations. When this frame reaches the child station 2 of No. 10, the child station 2 of No. 10 loops back the main transmission line 7 to the sub transmission line 8 as shown by the dotted line in FIG. As shown in FIG. 4, network reconfiguration by loopback on both sides of the failure point is completed.

As described above, the parent station 1
Transmits a frame for loop search only once to the slave transmission line 8 in the loopback process,
Only the frame of the loop-back command is sent to the child station 2, and the loop-back process can be completed with the minimum number of commands.

In the above-described embodiment, the number of the slave loop back station is written in the frame header area 4. However, the master loop back station number can also be written. If the backing station writes its own number, the parent station 1 can obtain the station number performing the main loopback through the frame.
You can check if is working.

[0025]

The present invention exhibits the following excellent effects.

(1) Since the station alone detects a failure in the transmission path and loops back to notify the number to the parent station, the parent station does not need to search, and the network can be reconfigured quickly. it can.

[Brief description of the drawings]

FIG. 1 is a network configuration diagram when a return from a slave system to a main system is performed in a transmission system to which the network configuration control method of the present invention is applied.

FIG. 2 is a configuration diagram of a frame in the network configuration control method of the present invention.

FIG. 3 is a network configuration diagram when a return from a master system to a slave system is performed in the transmission system of FIG. 1;

FIG. 4 is a network configuration diagram when network reconfiguration is completed in the transmission system of FIG. 1;

FIG. 5 is a network configuration diagram of a loop transmission system using a double transmission line.

FIG. 6 is a network configuration diagram showing a network reconfiguration of a transmission system according to the related art.

[Explanation of symbols]

 Reference Signs List 1 parent station 2 child station 3 frame 4 frame header area 7 main transmission path 8 sub transmission path 9 loopback station number area

Claims (4)

[Claims] 1. A double-loop network is constructed by sequentially connecting one parent station and one or more child stations by a double transmission line, and circulating a frame through one of the transmission lines. Each station communicates by transmitting and receiving data to and from this frame, and the other transmission path is configured to be able to communicate in the reverse direction. If a failure occurs in the one transmission path, the stations in the stations on both sides of the failure point In the network configuration control method of a transmission system in which the network is reconfigured by returning between the transmission paths, each station detects a failure in the transmission path immediately upstream, and the station that has detected the failure performs return and its own station. The number is notified to the parent station, and the parent station instructs the station to turn around on the opposite side based on the notified station number. A network configuration control method. 2. The network configuration control system according to claim 1, wherein each station detects a failure in the transmission line when a carrier from the upstream of the own station is cut off. 3. The master station detects a failure in a transmission line due to a failure to receive the circulated frame, and the returning station sends a frame for notifying the number in a reverse direction. Item 3. The network configuration control method according to item 1 or 2. 4. The network configuration control method according to claim 1, wherein an area for writing the number of the station performing the return is provided in the frame.