JPH0535517A - Switching device for duplexing system - Google Patents

Abstract

PURPOSE:To obtain a switching device of a duplexing system which can stop the output of the undesired signals of a system whose fault is detected by its own fault detecting circuit when a fault occurs in another system. CONSTITUTION:Each system is provided with the fault detecting circuits 11a and 11b which contain the CPU 12a and 12b and detect the faults, and the bus interfaces 13a and 13b which stop the output of signals of a faulty system when a fault is detected. Then the fault detected by its own system is noticed to the fault detecting circuit of another system and the output data are transmitted via the bus interface of another system as long as this system is normal. The CPUs of systems are connected to each other via a bus 14 which monitors other systems and at the same time the fault detecting circuits of systems are separated from each other via the bus interfaces of other systems and then connected to each other via the control buses 15 and 16. Then the fault that can not be detected by its own system is monitored by a CPU of another system, and the fault of another system is detected by the fault detecting circuit of its own system and separated by the fault detecting circuit. Then the bus interface of another system is invalidated via the control bus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a duplexer switching device which is divided into an active system and a standby system.

[0002]

2. Description of the Related Art FIG. 2 shows, for example, JP-A-63-240145.
It is a conventional duplexer type switching device disclosed in Japanese Patent Publication No. JP-A-2003-242242. In the figure, 1a and 1b are system switching devices, 2a and 2b are fault detection circuits, 3a and 3b are bus interfaces,
Reference numerals 4a and 4b are control signals for controlling the bus interface, and reference numerals 8 and 9 are failure notification signals for notifying other systems of failures in each system.

The conventional duplexer switching device is constructed as described above, and one system (for example, 1a) operates as an active system and one system (for example, 1b) operates as a standby system. Input data 5 normally input to the fault detection circuit 2a of the active system 1a
a is output as output data 7a from the bus interface 3a.

When a failure occurs in the active system, it is detected by the failure detection circuit 2a in the active system and notified to the failure detection circuit 2b in the standby system 1b, and the bus interface 3a is disabled via the control signal 4a. The output data 7a of the system is stopped. In the fault detection circuit 2b of the standby system,
When the failure detection signal from the active system is received and the failure notification signal 9 is received, when the standby system is normal, the bus interface 3b in the standby system outputs the input data 5a of the standby system to the output data 7
Output as b.

In addition, as a conventional example 2, JP-A-61-3
There is a 9825 publication. With regard to the duplication of the power supply device, by driving the power supply control circuit by the power supply of the other system, the power supply of the power supply failure circuit is prevented from becoming abnormal when the power supply failure of the own system occurs, and the power supply failure is surely detected. It was done like this.

Further, as a conventional example 3, Japanese Patent Laid-Open No. 2-173
There is an 832 publication. This is a system that transfers data between the active system and the standby system, and detects the power failure of other system in the own system so that unnecessary data is not transferred to the own system when the power failure occurs in the other system. However, when it is detected, the data transfer gate in the own system is closed to stop the data transfer from the other system.

Further, as a conventional example 4, Japanese Patent Laid-Open No. 3-42
There is a 943 publication. This is a watchdog timer means, a health check means, a loop monitoring means for monitoring the failure of the own system by itself, an intersystem communication state monitoring means for monitoring the state of the communication function between the own system and the partner system, It has a line switching device that switches and monitors the line between the system and the partner system,
The watchdog timer prevents the system from switching unnecessarily due to a malfunction, and the loop monitoring means ensures that the partner system is notified of the failure.

[0008]

Since the conventional duplexer switching device shown in FIG. 2 is constructed as described above, when a failure which cannot be detected by the own system occurs in the working system, the standby system is operated. Since the active system is not switched, the fault detection circuit 11a does not output the signal for invalidating the bus interface 3a by the control signal 4a. Therefore, the output data 7a from the faulty system
Does not stop, an unnecessary signal may be output, and the contents of the output destination memory etc. may be destroyed.

Further, in the conventional example 2 and the conventional example 3, only the power source is monitored, and with respect to other faults, the fault of the other system cannot be found in the own system, and the fault occurs to the external bus. Unwanted data may be output from the generated system.
Further, in the conventional example 4, although switching and monitoring can be performed accurately, the surviving system does not have a means for stopping the output from the faulty system to the external bus as described above, and the output of the faulty system does not occur. It may be output to the external bus.

The present invention has been made in order to solve such a problem. When the fault detection circuit in each system is provided with means for detecting a fault in the other system, when a fault occurs in another system. Another object of the present invention is to provide a duplexing system switching device capable of stopping the output of an unnecessary signal of a system in which a failure has occurred from a failure detection circuit in its own system.

[0011]

SUMMARY OF THE INVENTION A duplexing type switching device according to the present invention is a duplexing type switching device which is divided into an active system and a standby system, and has a failure detection circuit which has a central processing unit and detects a failure. , Each system has a bus interface that stops the signal output of the fault system when a fault is detected,
When a fault detected by its own system is notified to the fault detection circuit of another system, and when the other system is normal, the output data is sent out via the bus interface in the other system, and the other central processing units of each system are connected to each other. Connect by the system monitoring bus, disconnect the fault detection circuit of each system from the bus interface of the other system and connect it by the control bus, and monitor the fault that cannot be detected by the own system by the central processing unit of the other system. A failure detection circuit in the own system detects the failure, and the failure detection circuit disconnects the failure to disable the bus interface in the other system via the control bus.

[0012]

In the present invention, each system detects a fault in the other system by the fault notification signal and message from the other system, and the fault detection circuit in each system invalidates the bus interface in the fault system by the detected fault. A signal that suppresses the output of an unnecessary signal is output from the fault system.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a duplexer switching device according to the present invention. The switching device according to the device of this embodiment has the same configuration in both the active system and the standby system. In this embodiment, the CPU in the failure detection circuit is also used for normal processing, and in FIG. 1, 10a and 10b are processor modules (hereinafter referred to as PM). Also, 11a and 11b
Is a fault detection circuit, 12a and 12b are CPUs that perform other system monitoring and normal processing, 20 and 21 are fault notification buses, and 22
Is the system bus. Reference numerals 13a and 13b are bus interfaces for connecting the fault detection circuits 10a and 10b to the system bus 22, 14 is another system monitoring bus for detecting a fault of another system, and 15 and 16 are partner system bus interfaces 13a and 13b. The control bus is separated from the system bus 22.

Next, the operation of the above embodiment will be described with reference to FIG. First, during normal operation, the active PM (for example, 10a) executes the processing, and the output of the duplex system is output as the output data 19a through the bus interface 13a. On the other hand, in the standby PM (eg 10b), the CPU
12b passes through the other system monitoring means 14 and C of the active system PM 11a
By regularly exchanging messages with the PU 10a, the failure of the active PM 10a is monitored.

Next, a case where a failure occurs in the active PM 10a will be described. The fault detected in the fault detection circuit 11a in the active system PM10a is notified to the fault detection circuit 11b in the standby system PM10b through the fault notification bus 21 as in the conventional example, and the active system standby system is replaced and the control signal is sent. Bus interface 1 by 17a
3a becomes invalid and the output data 19a of the active system is stopped. Then, the spare system bus interface 13b sends the spare system output data 19b to the system bus.

On the other hand, the operation when a failure that cannot be detected occurs in the failure detection circuit 11a in the active PM 10a will be described below. Such a failure of the working system is caused by C of the backup system 10b.
When the message transmitted to the PU 12b through the other system monitoring bus 14 is interrupted, the failure detection circuit 11b detects the message. The fault detection circuit 11b in the standby PM 10b that has detected the fault immediately disconnects the bus from the bus interface 13a in the active PM 10b via the control bus 16.
Is invalidated, and the output data 19a from the active PM 10a, which is the fault PM, to the system bus is stopped. After that, the standby system PM 10b becomes the active system, continues the process, and sends the output data 19b to the system bus 22.

When a failure occurs in the standby system 10b, the standby system 10b itself or the active system 10b is processed in the same manner as above.
a detects a failure and system switching does not occur, but the bus interface 1 of the standby system 10b by the active system 10a
3b is invalidated, and the output of the output data 19b from the standby system 10b to the bus 22 is stopped.

[0018]

As described above, according to the present invention, a fault that cannot be found in the own system is found by another system, and the bus interface in the faulty system can be disabled from the other system. Since the output of is not erroneously output, the processing can be continued without affecting the surroundings even if the failure system is not stopped immediately.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a duplexer switching device according to the present invention.

FIG. 2 is a configuration diagram of a conventional duplexer switching device.

[Explanation of symbols]

 10 processor module 11 failure detection circuit 12 central processing unit (CPU) 13 bus interface 14 other system monitoring bus 15, 16 disconnection control bus 17 control signal 18 input data 19 output data 20, 21 failure notification bus 22 system bus

Claims (1)

Claim: What is claimed is: 1. In a switching system of a redundant system, which is divided into an active system and a standby system, a failure detection circuit having a central processing unit inside to detect a failure, and a failure system signal output when the failure is detected. Each system is equipped with a bus interface that stops the operation, and notifies the fault detection circuit of the other system to the fault detection circuit of the other system, and when the other system is normal, outputs the output data through the bus interface in the other system. In addition, the central processing unit of each system is connected by another system monitoring bus, and the fault detection circuit of each system is disconnected from the bus interface of the other system and connected by the control bus to prevent other faults that the system cannot detect. It is monitored by the central processing unit of the system, and the fault detection circuit in its own system detects a fault in the other system and disconnects it by the fault detection circuit to establish a bus interface in the other system via the control bus. Duplexing system of the switching device, characterized in that the effect.