JPH04342333A - Diagnostic system for local area network - Google Patents

Abstract

PURPOSE:To guarantee backup by a standby system for the fault of an operating system by diagnosing the standby system of a local area network equipped with the loop-shaped transmission line of configuration doubling the operating system and the standby system while working the operating system. CONSTITUTION:A test command is transmitted from a loop monitor device 2 through an operating system cable 41 to a required loop interface device 10. When the loop interface device 10 judges that the command is addressed to the own device, a photo-electric conversion part 11 is turned to a bypass mode, the logical normality of the standby system is tested by a diagnostic part 133 while using built-in data, and the result is reported through a standby system cable 42 to the loop monitor device 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for diagnosing a local area network, and more particularly to a method for diagnosing a local area network having a loop-type transmission line with a duplex configuration of an active system and a standby system.

0002

[Prior Art] Conventionally, this type of local area network diagnostic method uses shared equipment between the active system and the standby system, so it is necessary to interrupt the operation of the active system even when diagnosing the standby system. The system is designed to stop operation and perform diagnostics.

0003

[Problems to be Solved by the Invention] Since the above-described local area network performs normal data transfer in the operational system, it has a function that can immediately detect when a failure occurs. However, even if a failure occurs in the standby logic circuit or transmission line, it is not detected. If some kind of failure occurs in the active system in such a state, the network will be operated in loopback mode, but since this loopback uses the standby system, this state will also result in a failure, and as a result, use of external systems will cease.

0004

[Means for Solving the Problems] The local area network diagnostic method of the present invention has a redundant configuration in which at least one loop monitoring device and a plurality of external systems are connected to an active system and a standby system via respective loop interface devices. In a diagnosis method for a local area network connected to a loop-type transmission line, the loop interface device includes a test command reception unit that accepts test commands sent from the loop monitoring device via the operational transmission line, and a test command reception unit that receives the test commands. a test availability determining unit that determines whether or not the operational system is transmitting/receiving data when receiving the test; a bypass control unit that bypasses the input data of the transmission line of the operational system based on instructions from the test availability determining unit; A test starting unit that starts a diagnostic test according to instructions from the acceptability determining unit; a test data storage unit storing test patterns for use by this test starting unit; and test results from the test starting unit and the test data. a compare unit that compares the data corresponding to the test pattern stored in the storage unit;
It is constructed by having a reporting section that reports the comparison results in the conco pair section to the loop monitoring device via a standby transmission line.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of one embodiment of the present invention. In the embodiment of FIG. 1, external systems 1 and 3 are external processing systems connected via a local area network. The loop monitoring device 2 performs operational control of the local area network and information management for error detection. The optical cable 4 is a transmission line that connects the loop interfaces in a ring shape, and is composed of an active cable 41 and a standby cable 42. The loop interface device 10 is a central device as a local area network, converting optical signals to electrical signals, and transmitting and receiving data between a plurality of external systems 1, 3, etc.

The loop interface device 10 includes photoelectric converters 11 and 12 that convert optical signals of the active system and the standby system into electrical signals, and convert the electrical signals into optical signals.
Logic unit 13 that performs data transfer function and fault handling function
The logic section 13 has an active system control section 131, a standby system control section 132, and a diagnosis section 133, which is the main component of the present invention. The loop interface devices 20 and 30 connected to the loop monitoring device 2 and the external system 3, respectively, have the same configuration as the loop interface device 10 described above, and the 10 units with reference numerals are replaced by 20 units and 30 units, respectively. It is shown as 30 units.

Next, the normal data transfer operation in the above configuration will be explained. For example, in data transfer from external system 1 to external system 3, data output from external system 1 is first output to logic unit 13 of loop interface device 10 according to a predetermined protocol. The logic unit 13 transfers this data to the photoelectric conversion unit 11, which is the active system, and waits. Leading commands called tokens are generated within the local area network at regular intervals. When the token arrives on the active photoelectric converter 11, the previously awaited data is added to the end of the token and carried to the active cable 41 within the local area network, making one circuit within the local area. When the data added to the token makes one round, the data transferred to the external system 3 is taken into the active photoelectric conversion unit 31 of the loop interface device 30, and checked to see if it is the own address. As a result of the check, if it is the own address, the data is fetched and sent to the logic section 33. The logic unit 33 sends data to the external system 3 according to a predetermined protocol.

Next, an overview of diagnosis of the standby system of the loop interface device 10 will be explained. When the loop monitoring device 2 issues a command to test the standby system, the command is sent from the logic unit 23 of the loop interface device 20 to the active photoelectric conversion unit 11 of the loop interface device 10 via the active photoelectric conversion unit 21. The command data is sent to the operational control unit 131. The active system control unit 131 checks whether data is currently being transferred in the active system, and if not, issues a diagnostic start command to the diagnostic unit 133 and puts the active photoelectric conversion unit 11 into bypass mode. . The diagnostic unit 133 checks the logic of the standby system control unit 132 using diagnostic data held in advance, and determines whether it is normal or not. The diagnosis result is the standby photoelectric conversion unit 1
2 to the standby system cable 42, and is transferred to the loop monitoring device 2 via the standby system photoelectric conversion unit 22.

FIG. 2 is an internal block diagram of the diagnosis unit shown in FIG. 1, in which a command receiving unit 101 receives commands from the loop monitoring device 2 via the active system, and determines whether the active system is transferring data. A test propriety determination unit 102 that activates a test command, a test command activation unit 103 that activates a test command, a test data storage unit 104 that stores test data, a test result storage unit 105 that stores standby system test results, and test data and test results. Compare section 1 that compares
06, a reporting unit 107 that reports whether the comparison result is normal or not to the loop monitoring device 2, and a bypass control unit that bypasses the active system when starting a test and cancels the bypass when the test is completed. Next, the internal operation of the diagnostic section will be explained with reference to FIG. When a test command is input by the operator from the loop monitoring device 2,
The test command receiving unit 101 receives this command via the operational system control unit 131. When a test command is received, the test availability determining unit 102 determines whether the active system is currently transferring data, ie, whether testing is not possible, or whether the active system is not transferring data, ie, whether testing is possible. If the determination result is that the test is possible, the bypass control unit 108 is notified, the active system is put into bypass mode, and when the bypass completion notification of the active system is received from the bypass control unit 108, a start notification is sent to the test command starting unit 103. Therefore, the test command starting unit 103 performs internal diagnosis of the standby system using the data in the test data storage unit 104. This test result is stored in the test result storage section 105, and the test result is stored in the test data storage section 10.
It is compared with the data of No. 4 by the compare section 106. The reporting unit 107 receives the comparison results and reports a normal message if it is normal, and an abnormal message if it is abnormal to the loop monitoring device 2 via the standby cable 42. Note that the reporting unit 107 issues a bypass cancellation instruction to the bypass control unit 108 upon completion of the test.

[0011] In the above embodiment, one address is specified and the diagnosis is performed for each specified loop interface device, but it is also possible to issue a test command for all addresses to perform the diagnosis at once. It is clear that this can also be done.

0012

[Effects of the Invention] As explained above, the present invention is capable of diagnosing all logical units of the standby system during network operation, and when the active system enters loopback mode due to some kind of failure. Since the normality of the standby system is confirmed, the continuous operation of the network is guaranteed. Furthermore, it is possible to quickly respond to failures in the standby system, which also has the effect of reducing the burden on maintenance personnel.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a block diagram of a diagnostic section in FIG. 1;

[Explanation of symbols]

1, 3 External system 2 Loop monitoring device 4 Optical cable 10, 20, 30 Loop interface device 1
1, 12, 21, 22, 31, 32 Photoelectric conversion unit 13, 23, 33 Logic unit 41 Active cable 42 Standby cable 101 Test command reception unit 102 Test availability determination unit 103 Test command activation unit 104 Test data storage unit 105 Test result storage section 106 Compare section 107 Report section 108 Bypass control section 131 Active system control section 132 Standby system control section 133 Diagnosis section

Claims (1)

[Claims] Claim 1: A diagnostic method for a local area network in which at least one loop monitoring device and a plurality of external systems are connected to a loop-type transmission line with a duplex configuration of an active system and a standby system via respective loop interface devices. , a test command receiving unit that accepts a test command sent from the loop monitoring device to the loop interface device via the transmission path of the active system, and a test command receiving unit that receives the test command from the loop monitoring device via the transmission path of the active system, and determines whether the active system is transmitting or receiving data when receiving the test command. a bypass control unit that bypasses the input data of the operational transmission line in response to instructions from the test availability determination unit; and a test activation unit that launches a diagnostic test in response to instructions from the test availability determination unit. , Compare the test results from the test starting unit with the test data storage unit storing test patterns for use by this test starting unit and the data corresponding to the test patterns stored in the test data storage unit. 1. A diagnostic method for a local area network, comprising: a compare unit that performs the comparison, and a report unit that reports the comparison results of the compare unit to a loop monitoring device via a standby transmission line.