JPH03192892A - Switching control circuit - Google Patents

Abstract

PURPOSE:To find out an abnormal operation of a changeover control section before a fault takes place in an active device by always monitoring the normality of the changeover control section between the active device and a standby device. CONSTITUTION:An output of a monitor timing generating circuit 6 is applied to a selection circuit 1, a test signal generating circuit 3 and a holding circuit 5, the test signal generating circuit 3 outputs a test signal simulating every possible pattern, the selection circuit 1 selects an output of the test signal generating circuit 3 at the test and applies the result to a switching control section 2 and the holding circuit 5 prevents that the output of the switching control section 2 is transferred to a switching control object. The test operating timing is inserted periodically for the normal operating period and the system switching control section is always subjected to normality monitoring and if the switching control section has a fault, it is detected before the switching control section is actually operated.

Description

[Detailed Description of the Invention] [Summary] Regarding a switching control circuit that performs control to switch to a backup device when a failure occurs in the current device, the switching control circuit constantly monitors the normality of the switching control section between the current device and the backup device, and performs switching control. The purpose of this system is to detect operational abnormalities before they occur in the current equipment, by inputting a switching control signal based on the monitoring information of the current equipment, and switching to the backup equipment when a failure occurs in the current equipment. In a switching control circuit comprising a switching control section for controlling, a test signal generating circuit that generates a test signal that simulates all possible patterns of the switching control signal, the switching control signal, and the test signal. a selection circuit that selects one of the input signals; an output monitoring circuit that monitors the output of the switching control section in response to a test signal that simulates all possible patterns; and a monitoring timing that generates timing for testing the switching control section. The device is configured to include a generating circuit and a holding circuit that prevents the output of the switching control unit from being transferred to a switching control target when testing the switching control unit.

[Industrial application field]

The present invention relates to a switching control circuit that controls switching to a backup device when a failure occurs in a current device.

Systems that have a redundant configuration in which a spare device is installed to prevent the system from going down when a failure occurs in the current device, and the system switches from the current device to the backup device in the event of a failure are often used in the fields of communications and information processing. It is being

In such a system, a switching control unit between the active device and the standby device is provided to constantly monitor the operating status of each part of the active device, and apply the monitoring information to the switching control unit as a switching control signal. Switching control is performed.

The present invention relates to a technique for monitoring the normality of such a switching control section.

[Problems to be solved by the prior art and the invention]
Nowadays, in a configuration that includes a working device, a standby device, and a switching control section between the working device and the standby device, the normality of the switching control section depends on whether an abnormality occurs in the working device and the switching control section is not actually operated. It is first detected when switching control is not performed normally when attempting to do so.

However, if an abnormality in the switching control section is detected after an abnormality has occurred in the current device, the system will go down and the meaning of the redundant configuration will be halved.

The present invention has been made in view of the above problems, and constantly monitors the normality of the switching control unit between the active device and the standby device, and detects abnormal operation of the switching control unit before the abnormality occurs in the active device. It is an object of the present invention to provide a switching control unit monitoring circuit that detects the switching control unit.

[Means to solve the problem]

FIG. 1 is a basic configuration diagram of the present invention.

In FIG. 1, 1 is a selection circuit, 2 is a switching control section,
3 is a test signal generation circuit, 4 is an output monitoring circuit, 5 is a holding circuit, and 6 is a monitoring timing generation circuit.

The switching control unit 2 inputs a switching control signal based on monitoring information of the current device, and controls switching to a backup device when a failure occurs in the current device.

A test signal generation circuit 3 generates a test signal that simulates all possible patterns of said switching control signal.

The selection circuit 1 receives the switching control signal and the test signal and selects one of them.

The output monitoring circuit 4 monitors the output of the switching control section 2 in response to a test signal simulating all possible patterns.

A monitoring timing generation circuit 6 generates a timing for testing the switching control section 2.

The holding circuit 5, when testing the switching control section 2,
This prevents the output of the switching control section 2 from being transferred to the switching control target.

[Effect]

FIG. 2 shows the normal operation and test timings output by the monitoring timing generation circuit 6 of FIG. 1.

This output is applied to the selection circuit 1, the test signal generation circuit 3, and the holding circuit 5 configured as shown in FIG. During testing, the selection circuit 1 selects the output of the test signal generation circuit 3 and applies it to the switching control section 2, and the holding circuit 5 transfers the output of the switching control section 2 to the switching control target. to prevent it from happening.

During normal operation, the selection circuit 1 selects the original switching control signal and applies it to the switching control section 2, and the holding circuit 5 allows the output of the switching control section 2 to be transferred to the switching control target.

As shown in Figure 2, by periodically inserting the test operation timing as described above during the normal operation period, the switching control section of a system with a redundant configuration can constantly monitor its normality. If an abnormality occurs in the switching control section, the abnormality is detected before the switching control section actually operates.

[Example] Figure 3 shows a 0 system and a 1 system as an example of the present invention.
This figure shows the configuration of a switching control circuit that manually inputs alarm signals ALM from both systems and controls switching so that the O system or the 1 system is put into operation according to the state of these alarm signals ALM.

In FIG. 3, 11 is a selector, 12 is a switching control section, 13 is a pattern generation circuit, 14 is a pattern check circuit, and 15 is a holding circuit.

The selector 11 includes a switching control section 12 in the selection circuit 1.
is connected to the switching control section 2, the pattern generation circuit 13 is connected to the test signal generation circuit 3, and the pattern check circuit 14 is connected to the test signal generation circuit 3.
corresponds to the output monitoring circuit 4, and the holding circuit 15 corresponds to the holding circuit 5. The circuit that generates the monitoring timing is not shown in FIG.

FIG. 4 shows the operational logic of the switching control section 12 in the configuration of FIG. 3.

As shown in Figure 4, the 1 system is selected only when the alarm from the 0 system is valid and the alarm from the 1 system is not valid, so that the 0 system is used preferentially. It is designed to be controlled as follows.

FIG. 5 shows the timing in an embodiment of the invention.

As shown in FIG. 5, a switching control section monitoring operation time of 10 μs is inserted during the normal operation period of Looms. Then, within this lOμS switching control unit monitoring operation time, the pattern generation circuit 1 is activated by a timing signal that sequentially generates the four test patterns shown in FIG.
Control 3.

These timing signals can be generated by appropriately dividing the system clock. The pattern check circuit 14 monitors whether the output of the switching control section 12 corresponding to the input of each test pattern described above matches the output as shown in FIG. If there is an abnormality, it is detected as an abnormality in the switching control section 12.

〔Effect of the invention〕

According to the present invention, it is possible to constantly monitor the normality of the switching control section between the active device and the standby device, and to discover an operational abnormality in the switching control section before an abnormality occurs in the active device.

[Brief explanation of drawings]

FIG. 1 is a basic configuration diagram of the present invention. FIG. 2 is a diagram schematically showing timings outputted by the monitoring timing generation circuit 6 of FIG. 1 during normal operation and testing. FIG. 3 is an embodiment of the present invention. FIG. 4 is a diagram showing the operational logic of the switching control section 12 in the configuration of FIG. 3, and FIG. 5 is a diagram showing the timing in the embodiment of the present invention. (Explanation of symbols) 1--Selection circuit, 2-Switching control section, 3--Test signal generation circuit, 4-Output monitoring circuit, 5-Holding circuit, 6
- Monitoring timing generation circuit, 11- selector, 12-.
- Switching control section, 13-pattern generation circuit, 14-pattern check circuit, 15-holding circuit. Fig. 3 is a diagram showing the operational logic of the switching control circuit of Fig. 3. Fig. 4 is a diagram showing the timing of implementation of the present invention in five practical examples.

Claims (1)

[Scope of Claims] A switching device comprising a switching control unit (2) that receives a switching control signal based on monitoring information of the currently used device and controls switching to a spare device when a failure occurs in the currently used device. The control circuit includes: a test signal generation circuit (3) that generates a test signal that simulates all possible patterns of the switching control signal; and a selection circuit that receives the switching control signal and the test signal and selects one of them. (1), an output monitoring circuit (4) that monitors the output of the switching control section (2) in response to a test signal that simulates all possible patterns, and generating timing for testing the switching control section (2). and a holding circuit (5) that prevents the output of the switching control section (2) from being transferred to the switching control target when testing the switching control section (2). A switching control circuit comprising: