JPH03265247A - Fault detection system - Google Patents

Abstract

PURPOSE:To attain quick detection without provision of a monitor to each station by sending a monitor data between adjacent stations and discriminating it as an occurrence of a fault when no response data exists and sending fault information to a monitor. CONSTITUTION:A monitor data is sent among adjacent stations 21-24 or a local area network and when no response data comes from opposite stations 21-24 within a prescribed time, it is discriminated that a fault takes place in an opposite station and the station sends fault information 28 to a monitor 25 in common to the stations 21-24. Through the constitution above, it is not required to provide a monitor for each station and all the stations are not sequentially monitored, then fault detection is implemented quickly in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fault detection method for detecting a fault in a station in a local area network system.

[Prior Art] FIG. 2 is a block diagram of a local area network system using a conventional fault detection method. In Figure 2, 1, 2, 3, 4 are multiple stations that are connected via a transmission line and transmit and receive data, and 5 is a unique interface (transmission line L1) that is different from the connection interface between stations. This is a monitoring device that is connected to station 2 and monitors all stations 1, 2, 3.4 for failures. 6a is monitoring data sent from the monitoring device 5 to the station 2; 6b is response data sent from the station 2 to the monitoring device 5 (response data to the monitoring data 6a); 7a is sent from the monitoring device 5 to the station 3. monitoring data, 7b is station 3
This is response data sent from the server to the monitoring device 5.

Next, the operation of this conventional example will be explained. The monitoring device 5 sequentially and individually transmits monitoring data to all stations 1 to 4 existing in the local area network system, and checks whether the response data is returned within a certain period of time. The station is monitored and if it is not returned within a certain period of time, the station is considered to be faulty. For example, the monitoring device 5 transmits monitoring data 6a to the station 2, and monitors whether response data 6b is returned. Therefore, in the monitoring device 5, if the response data 6b is returned, the monitoring device 5
is considered normal, and then sends monitoring data 7 to station 3.
a, and monitor whether response data 7b is returned. In this way, the monitoring device 5 sequentially monitors all stations 1 to 4 for failures.

[Problem to be solved by the invention]

The conventional failure detection method operates as described above, and if the time from when the monitoring device sends monitoring data to the station to when it receives response data from the station is T, then after a station failure occurs, in the worst case, There was a problem in that it took TX (number of stations N) to detect a fault, and the fault detection efficiency was poor.

For example, as shown in Japanese Patent Laid-Open No. 63-142934, by setting adjacent stations as the stations to be diagnosed, it is now possible to determine which partial transmission line is at fault when a fault occurs. However, in this case, it is necessary to install a fault detection circuit in every station, which causes the problem that the hardware configuration of the station becomes complicated.

This invention was made in order to solve the above-mentioned problems, and it is an object of the present invention to obtain a fault detection method that can reduce the time required to detect a fault without requiring a fault detection circuit to be installed in each station. With the goal.

[Means to solve the problem]

The failure detection method according to the present invention transmits monitoring data between adjacent stations 21, 22, 23, and 24, and if response data is not returned within a certain time,
A normal station regards a station that does not have the response data as a faulty station, and transmits fault information 28 indicating that a fault has occurred in the station to the monitoring device 25, and thereby the monitoring device 25 detects a fault in the station. It is characterized by this.

[Effect]

For example, if the monitoring data 26a is sent from the station 21 to the station 22, and the response data 26b is not returned from the station 22 to the station 21 within a certain period of time, the station 21 considers the station 22 to be a faulty station. Monitoring device 25
The station 22 sends failure information 2B indicating that a failure has occurred. From this, the monitoring device 25 detects the occurrence of a failure in the station 22.

〔Example〕

FIG. 1 is a block diagram of a local area network system using a failure detection method according to an embodiment of the present invention. In Fig. 1, reference numerals 21, 22, 23, and 24 indicate a plurality of stations that are connected via transmission paths and transmit and receive data, and 25 indicates a unique interface (transmission path L1) different from the connection interface between stations.
is connected to station 22 and all stations 21゜2
This is a monitoring device that performs failure monitoring of 2.23.24. 2
6a is monitoring data sent from the station 21 to the station 22, 26b is response data sent from the station 22 to the station 21, 27a is monitoring data sent from the station 22 to the station 23, 27 and b are the station 23 This is response data sent from the station 22 to the station 22.

Next, the operation of this embodiment will be explained.

All stations 21 to 24 receive monitoring data,
If normal, the response data is sent back to the monitoring data source station, and the monitoring data is sent.
It also has the function of regarding the destination station as a failure if response data is not returned from the destination station within a certain period of time. For example, the station 22 transmits monitoring data 27a to the station 23, and the station 23 sends response data 27b.
or station 23 if it is not returned within a certain period of time.
is regarded as a faulty station, and sends fault information 28 indicating that the station 23 is faulty to the monitoring device 25. As a result, the monitoring device 25 detects the occurrence of a failure in the station 22.

Similarly, station 21 also transmits monitoring data 26a to station 22, and monitors whether response data 26b is returned. station 24
and station 21. A similar operation is performed between station 23 and station 24. In this way, the monitoring device 25 can monitor all stations 21-24 for failures.

In the above embodiments, a local area network system having a loop type configuration has been described, but the same effect can be obtained also for a local area network system having a bus type configuration.

[Effects of the Invention] As described above, according to the present invention, if monitoring data is transmitted between adjacent stations and response data is not returned within a certain period of time, a normal station will not have the corresponding response data. The station is regarded as a station in which a fault has occurred, and the fault information indicating that the station has a fault is sent to the monitoring device, which causes the monitoring device to detect a fault in all stations. There is no need to install a circuit, which reduces the complexity of the hardware at each station.Also, the monitoring device does not need to monitor all stations sequentially, which significantly reduces the time required to detect a fault. This has the effect of improving failure detection efficiency.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a local area network system using a failure detection method according to an embodiment of the present invention, and FIG. 2 is a configuration diagram of a local area network system using a conventional failure detection method. FIG. 1 is a configuration diagram of a system. 21-24...station, 25...monitoring device,
26a, 27a--monitoring data, 26b, 27b-
...Response data, 28...Fault information, L, Ll
...Transmission line.

Claims (1)

[Claims] A local area comprising a plurality of stations connected via a transmission line to send and receive data, and a monitoring device connected to at least one of the plurality of stations to monitor failures of all stations. - In a network system, if monitoring data is sent between adjacent stations and response data is not returned within a certain period of time, a normal station will consider the station without the response data to be a faulty station. Sends fault information indicating that the station has a fault to the monitoring device,
A fault detection method characterized in that the monitoring device thereby detects a fault in the station.