JPH0260338A - Bus type lan - Google Patents

Abstract

PURPOSE:To facilitate the detection of a generation place, to rapidly execute the recovery and to improve a reliability when a trouble occurs at a doubled bus type LAN transmission line by providing a trouble diagnosing communicating means, a trouble detecting means and the like at a control station. CONSTITUTION:A node station STN1 as a control station is connected through bus-shaped transmission lines BUS1 and 2 to nodestations STN2, 3...n as an ordinary station, respective types of control information and the like of respective stations are collected by polling for respective ordinary stations and a trouble is detected. Namely, when a trouble occurs at one side of the BUS1 and 2 for the STN1, both normal BUS and troubled BUS are used, and the trouble diagnosing communication is executed through a transmitting control device 24 for all ordinary stations. The diagnosed result obtained from both BUSs is compared with a network control information table in the RAM 23 and the troubled place of the BUS is detected and stored into the RAM 23. Thus, when the trouble occurs at the BUS1 and 2, the detection of the generated place is facilitated, the recovery can be executed in a short period and the reliability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a bus-type LAN, and more specifically to a token passing method in which transmission is controlled based on a logical ring representing the order in which 1--kuns are sequentially delegated. Bus type ■, A
Regarding N.

(Summary of the Invention) This invention enables fault diagnosis communication from a management station to all normal stations using both transmission paths when a failure occurs in one transmission path of a knee-multiplexed lotus type LAN. By comparing and contrasting the diagnosis results obtained from both transmission lines to detect the failure location and storing the failure location data, the system attempts to facilitate recovery processing in the event of a failure. be.

(Prior art and its problems) Lotus type 1. , AN's transmission control method is 1.-- in which only stations with access rights to the transmission path, or so-called tokens, transmit data, and the tokens circulate along a logical ring among the stations connected to the transmission path. There is a Kumbhasosingka ceremony.

In the Hassle Type I and HN systems, the transmission path may be duplicated in order to improve system reliability. Conventionally, heavy bus type 1. In AN, as a processing method when a failure occurs in a specific node section of one transmission path, each communication node uses the failed transmission path to perform a failure diagnosis on other communication nodes every time it holds a token. Communication was carried out and the diagnosis results were accumulated. In this way, when the token goes around the logical ring while communicating for fault diagnosis, each communication node stores the respective diagnosis results.

Furthermore, by integrating these diagnostic results in one communication node, it is possible to obtain failure location data for the entire network.

However, in this method, all the communication nodes on the logical ring perform diagnostic communication to detect the failure location, which increases the processing time to complete the diagnosis and complicates the processing at each communication node. There is a problem with becoming.

(Object of the invention) This invention was made to solve the problem mentioned in 1.
To provide a highly reliable bus-type AN that can easily detect the location of failure and restore it in a short time when a failure occurs in the transmission line of the AN.

(Structure and Effects of the Invention) In order to achieve the object described in item 1, the present invention provides a bus-type LAN in which transmission is controlled by a token passing method based on a logical ring using a duplex transmission line, in which a communication node is connected to a management station. and multiple ordinary people, and
It is installed at the management station, and when a failure occurs in one transmission line, it uses both the normal transmission line and the transmission line where the failure occurred.
A communication means that performs fault diagnosis communication to all normal stations, a detection means that compares the diagnosis results obtained from both transmission lines by this means and detects a fault location on the transmission line, and stores data on the detected fault location. It is characterized by having a storage means for storing information.

The bus type LAN according to the present invention has a dual bus type L
When a failure occurs in one transmission line of the AN, the management station uses both transmission lines to perform failure diagnosis communication to all normal stations, and compares and contrasts the diagnosis results obtained from both transmission lines to determine the failure. Each time a location is detected and the failure location data is stored, the following effects can be obtained.

(It is possible to accurately detect the location where a failure occurs on the AL transmission path.

(Failures that occur on the BL transmission path can be recovered in a short time.

(For the C1 normal station, failure diagnosis processing is not necessary, and the algorithm is simplified accordingly.

(The reliability of the entire system increases as detection of the dl failure location and recovery become more reliable and faster.

(Description of Embodiments) FIG. 1 is a diagram showing the overall configuration of a bus-type LAN according to the present invention.

In the figure, BLJSl and BUS2 are bus-like transmission lines,
5TNI, 5TN2...S"rNn is the transmission line BU
It is a node station connected to SI and BUS2. Of these, 5TN1 is a management station node in the bus type LAN, and has the function of collecting various management information including the operating status of other stations and detecting failures by polling the other private nodes 2 to N. ing. Node 2, which is a normal citizen
N is a node with no detection function.

The transmission of the node stations 5TN1, 5TN2, .

Two transmission lines BtJS1. BtJS2 is provided to construct a duplex bus, and when one transmission line goes down, the remaining transmission line can prevent the system from going down.

FIG. 2 is a block diagram showing the internal structure of the node station 5TN1. As shown in the figure, S T NI is CPL
J21, ROM22, RAM23, transmission control device 24,
and an internal bus IB that connects these. The CPU 21 controls the transmission control device 24 according to the program stored in the ROM 22 to
Transmission and reception of various frames between the I and BUS2, and processing for diagnosing faults occurring in the transmission path, etc., are performed.

The RAM 23 is used as a buffer for storing network management information, transmission path failure information, transmission/reception data, and other various data.

FIG. 3 is a diagram showing the configuration contents of the network management information pulls 31 and 32 provided in the RAM 23 of the node station 5TNI.

Tables 31.32 show the transmission paths HU S l and BU
Each node is provided for S2, and various management information regarding each node station 5TNI to n of network 1- is stored, and the internal memory area address and the node number of each node station 1-n correspond to each other. ing.

For example, each memory area includes a memory area 31-i.
, 32-i, a communication information area and a non-response information area "r" are formed.

In the 1J11 communication availability information area, logical ring participation information of the communication node to which the address corresponds is written.

That is, when this area is on, it indicates that the corresponding communication node has joined the logical ring, and when this area is off, it indicates that it has left the logical ring.

In the non-response information area, whether or not there is a response when specific data is sent to the corresponding communication node is written (
There is. In other words, if this area is on, it indicates that there is a failure in the transmission line related to the corresponding communication node, or that an abnormality has occurred in the communication node itself, and if this area is off, it indicates that the transmission line system related to the corresponding communication node is normal. .

FIG. 4 is a diagram showing the configuration contents of a transmission path failure information table 41 provided in the RAM 23 of the node station 5TNI.

The table 41 stores failure information of both transmission lines regarding each node 1 to n of the network L, and the memory area address in the table 41 corresponds to the node number of each node station 1 to n.

For example, each memory area includes a memory area 41-i.
As shown in , a failure information area for the transmission line BUSI and a failure information area for the transmission line B tJ S Z are respectively formed.

These failure information areas can display failures for each transmission line and their occurrence locations.

In other words, if ON is written in the area of table 41, a failure has occurred in the transmission line system on the written side, and communication with the communication node at the corresponding address is impossible even if this transmission line is used. Show that something is true.

FIG. 5 is a flowchart showing a failure point detection process when a failure occurs in the transmission path in the node station S'rN1.

When the node station 5TNI detects a failure that has occurred in a transmission line, it uses the failed transmission line and polls the corresponding normal stations in order from the top address of the network management information table for that transmission line. Send a frame (
Step 501).

Here, if a response frame to the transmitted polling frame is received (step 502, affirmative), OFF is entered in the non-response information area of the corresponding network management information table (step 504), and the process proceeds to step 506.

If a response frame cannot be received even after a certain period of time has elapsed (step 502 negative, step 503 affirmative), the corresponding non-response information area is marked on (step 50
5).

Next, refer to the network management information table and check whether polling frame transmission has been completed to all stations (step 506). If the polling frame has not been completed, the process advances to step 501 and the polling frame transmission is repeated.

When polling frame transmission has been completed to all stations (step 506, affirmative), the next normal transmission path is referred to the network management information table for normal transmission paths, and the same procedure as in item 1-1 is performed. A polling frame is transmitted (steps 507 to 512).

When the failure diagnosis communication for each normal station is completed for both transmission lines, the contents of the network management information tables for both transmission lines are compared for each node starting from the top address (step 513).

If the contents of both non-response information areas match (Yes at step 514), OFF is placed in both failure information areas of the corresponding node address of the transmission path failure information chifur (
Step 515).

If the contents of the non-response information areas of both sides do not match (No in step 514), the failure information area for the corresponding transmission path in the transmission path failure information file is set to on (step 51).
6).

When the comparison process for all the non-response information areas is completed (step 517 is affirmative), the node station S'N1 aggregates all the data regarding the failure locations of both transmission lines and stores it in the transmission line failure information table. . Based on this failure data, the node station 5TNI can perform failure recovery processing such as changing the transmission path.

In addition, in the above process, when comparing the non-response information areas, if you simply move the contents of the non-response information areas for each transmission line to their respective fault information areas, both of the corresponding fault information areas will be turned on. If so, it can be recognized that there is a problem with the normal opening itself.

As described below, in this invention, by diagnosing a failure that occurs in a duplex transmission line for each ordinary citizen through polling performed by the management station, the diagnostic processing is concentrated on the management station, and the ordinary people can save time. Algorithm processing can be streamlined.

Furthermore, by diagnosing faults using both transmission lines at the management station, the location of the fault can be found reliably and quickly, resulting in faster recovery processing and improved reliability of the entire system.
1- can be made.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a bus-type LAN according to the present invention, FIG. 2 is a block diagram showing the internal structure of a management node station 5TNI, FIG. 3 is a configuration diagram of a network management information table, and FIG. FIG. 5, which is a configuration diagram of the transmission path failure information table, is a flowchart showing the failure location detection process. BUSI, BLJS2...Bus-shaped transmission line S'
FNl...Management node station 5TN2~n...Normal node station 21...
...CPtJ 22...ROM 23...RAM 24...Transmission control device 1B...Internal bus

Claims (1)

[Scope of Claims] 1. In a bus-type LAN in which transmission is controlled by a token passing method based on a logical ring on a duplex transmission path, a communication node is constituted by a management station and a plurality of normal stations, and the communication node is configured in the management station. When a failure occurs in one transmission line, both the normal transmission line and the failed transmission line are used.
A communication means that performs fault diagnosis communication to all normal stations; A detection means that compares the diagnosis results obtained from both transmission lines using this means and detects a fault location on the transmission line; and stores data on the detected fault location. A bus-type LAN characterized by comprising: a storage means for storing information;