JP2569892B2 - Switching control monitoring circuit - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching circuit for switching between two control targets, and more particularly to malfunctioning by detecting a mismatch between switching information of the switching target and switching operation of the switching control circuit. And a switching control monitoring circuit that detects

[Conventional technology]

A conventional switching control circuit, as shown in FIG.
The switching unit 1 includes an operating system A2 and an operating system B3. The switching unit 1 includes a set / reset flip-flop 20 (hereinafter, referred to as an RS flip-flop) as shown in FIG. 2B. The switching unit 1 is connected to the working system A2 and the working system B3 by the switching control signal 4, the working system A2 and the switching unit 1 are connected by the warning signal 7, and the working system B3 and the switching unit 1 are connected by the warning signal 5. Have been. In the switching unit 1, one input terminal ALM1 of the RS flip-flop 20 receives the alarm signal 7 from the active system A2, and the other input terminal ALM2 is connected to the active system B3.
, And the output terminal SEL outputs the switching control signal 4 to the active system A2 and the active system B3.

The switching unit 1 receives the alarm signal 7 of the operation system A output from the operation system A2 or the alarm signal 5 of the operation system B output from the operation system B3, and selects an operation system to which no alarm signal is output. As described above, the switching control signal 4 is output to the active system A2 and the active system B3.

That is, the alarm signals 7, 4 in the operation system A2 and the operation system B3
The selection condition of (1) will be described with reference to Table 1 below. If the operating system B3 is abnormal, the operating system A2 is selected (the alarm signal 5 is "0" and the switching control signal 4 is "1"). When A2 is abnormal, the operation system B3 is selected (the alarm signal 7 is "0" and the switching control signal 4 is "0"). When both the active system A2 and the active system B3 are abnormal, the active system A2 is prioritized (alarm signals 7, 5 are "0", the switching control signal 4 is "1"), and the active system A2 and the active system B3
Is normal, the previous system is held and the first selected operating system is held (alarm signals 7, 5 are "1", and switching control signal 4 is "1 or 0").

The alarm signal logics of the active system A2 and the active system B3 are “1” normal and “0” abnormal, and the logic of the switching control signal 4 is “1”.
Indicates that the active system A2 is selected, and "0" indicates that the active system B3 is selected.

[Problems to be solved by the invention]

In the conventional switching control circuit, the switching control signal 4 is sent to the active system A2 and the active system B3 to designate the active system. However, there is also a means for reading the switching control information for knowing the switching state of the active system. Therefore, there is a disadvantage that it is not possible to determine whether the switching control has been normally performed on the active system.

Further, such a switching control circuit can perform switching control, but has a drawback that it cannot be verified whether or not the operating system has been normally switched by the switching control signal.

SUMMARY OF THE INVENTION An object of the present invention is to provide a switching control monitoring circuit which can solve the above-mentioned drawbacks and can verify whether or not the switching control of the active system has been performed reliably.

[Means for solving the problem]

The switching control monitoring circuit of the present invention transmits an alarm signal when a failure occurs, switches to a normal operation system when receiving the switching control signal, and returns the switching control signal as switching control information to the first and second operation systems. Upon receiving the alarm signal from the first or second operating system,
The switching control signal is output to the first and second operating systems to instruct to switch to the normal operating system, and the switching control information and the switching control signal returned from the first and second operating systems are returned. And a switching unit that outputs an alarm output signal and detects a switching abnormality of the active system if the two do not match.

In the switching control audit circuit according to the present invention, the switching unit inputs an alarm signal from the first and second operating systems to a set input terminal and a reset input terminal, and outputs a switching control signal for switching to a normal operating system to the first operating system. And a first flip-flop that outputs to the second operating system, and a second flip-flop that inputs the switching control information returned from the first and second operating systems to the set input terminal and the reset input terminal and outputs the result. Detecting a mismatch between the switching control and the switching control information from the outputs of the flip-flop and the first and second flip-flops, and if not, outputting an alarm output signal to detect a switching abnormality of the active system A logic element.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a view showing one embodiment of the present invention.
Is a circuit block diagram, and (b) is a circuit diagram.

The switching control monitoring circuit includes a switching unit 1, a first operating system A2, and a second operating system B3. The switching unit 1 includes a first RS flip-flop 9, It comprises a second RS flip-flop 11, an inverter element 10, and an exclusive OR element 12.

The switching unit 1 includes an operation system A2 and an operation system B3 and a switching control signal 4
Alarm signal from operation system A2 and operation system B3
7, 5 and are connected to the alarm output signal 13 and the outside. Further, in the switching unit 1, the switching control signal 4 is transmitted to the operation system A2.
And the switching control information 8, 6 returned by the operation system B3.

The switching unit 1 has a circuit configuration as shown in FIG. 1 (b). The input terminal SEL1 is connected to one end of the input of the RS flip-flop 9, and the input terminal SEL2 is connected to the inverter element.
10 is connected to the other end of the input of the RS flip-flop 9, and the output of the RS flip-flop 9 is connected to the exclusive OR element 12.
Is connected to one end of the input. The input terminal ALM1 is connected to one end of the input of the RS flip-flop 11, and the input terminal ALM2
Is connected to the other end of the input of the RS flip-flop 11, and the output of the RS flip-flop 11 is connected to the other end of the input of the exclusive OR element 12 and the output terminal SEL. The output of the exclusive OR element 12 is connected to the coincidence output terminal ALM0. The switching control signal 4 from the switching unit 1 to the active system A2 and the active system B3 is output from the output terminal SEL, the alarm signal 7 from the active system A2 is input to the input terminal ALM1, and the alarm signal 5 from the active system B3 is Input to input terminal ALM2. Further, the switching control information 8 of the switching control signal 4 looped back by the active system A2 is input to the input terminal SEL1, and the switching control information 6 looped back by the active system B3 is input to the input terminal SEL2.

The switching unit 1 receives the alarm signal 7 of the operation system A output from the operation system A2 or the alarm signal of the operation system B output from the operation system B3, and selects an operation system to which no alarm signal is output. Thus, the switching control signal 4 is output.

The active system A and the active system B return the received switching control signal 4 to the switching unit 1 as the switching control information 8,6.

The switching unit 1 always monitors the returned switching control information 8,6. Then, the result of the match and mismatch (alarm output signal 13) by the monitor is output from the match output terminal ALM0.

When a failure occurs, the active system A2 and the active system B3 output alarm signals 7, 5 to the switching unit 1. The switching control signal 4 from the switching unit 1 is returned to the switching unit 1 as switching control information 8,6.

The RS flip-flop 11 of the switching unit 1 has an input terminal (ALM
1, ALM2), an alarm signal from the active system A2 and the active system B3 is input, and the switching system between the active system A2 and the active system B3 is selected. The switching control signal 4 that has selected the switching system is output from the RS flip-flop 11 to the active system A2 and the active system B3 via the output terminal SEL. The switching control signal 4 is also output to one terminal of the exclusive OR element 12.

The RS flip-flop 9 inputs the switching control information 6, 8 of the active system A2 and the active system B3 from the input terminals (SEL2, SEL1), and outputs the result to the other terminal of the exclusive OR element 12. That is, the switching control information 6 input from the input terminal (SEL2)
Is RS after the signal logic is inverted through inverter 10
The switching control information 8 input to one terminal of the flip-flop 9 and input from the input terminal (SEL1) is input to the other terminal of the RS flip-flop 9. The output result is provided to one input terminal of the exclusive OR element 12.

The exclusive OR element 12 is provided for the purpose of detecting whether or not the two inputs match, and the output result is output to the external circuit as the alarm output signal 13 from the match output terminal (ALM0).

This coincidence detection is based on the results of the RS flip-flop 9 in which the switching control signal 4 output from the switching unit 1 is turned back as switching control information 8 and 6 by the active system A2 and the active system B3, respectively, and the alarm signals 7 and 5. Control is performed so that the result of the RS flip-flop 11 becomes the same. For this reason, when the output of the RS flip-flop 9 and the output of the RS flip-flop 11 match, it is normal, and when they do not match, it is abnormal.

Next, the operation logic of the switching unit 1 in this embodiment will be described with reference to Table 2 below. When the operation system B3 is out of order, the alarm signal 5 ("0" due to abnormality) is input from the operation system B3 to the RS flip-flop 11 input terminal (ALM2) of the switching unit 1, and the output terminal (SEL) is output from the RS flip-flop 11. The switching control signal 4 is output to the active system A2 and the active system B3 via the switch. Here, "1" of the switching control signal 4 means switching to the active system A2. Then, the switching control signal 4 is looped back by the active system A2 and the active system B3, and is input to the input terminals (SEL1, SEL2) of the RS flip-flop 9 as the switching control information 8, 6. When the switching control information 8, 6 input to the input terminal of the RS flip-flop 9 matches "1" or "1", the exclusive OR element 12 outputs a normal, that is, "0" alarm output signal 13. When one or both of the switching control signals 8 and 6 are “0”, the exclusive OR element 12 outputs an abnormality, that is, an alarm output signal 13 of “1”. Next, the active system A2 fails, the alarm signal 7 is input from the active system A2 to the RS flip-flop 11 input terminal (ALM1) of the switching unit 1, and "0" is output from the RS flip-flop 11 via the output terminal (SEL). Is output to the active system A2 and the active system B3. Also in this case, as described above, when the switching control information 8, 6 to the RS flip-flop 9 matches "0" and "0", the value is normal and "0", and when they do not match, it is "1".

As described above, the normality or abnormality of the switching system can be determined from the output of the exclusive OR element 12. By using this output, the normal operation of the switching system of the active system A2 and the active system B3 can be confirmed and the switching system can be determined. Can be detected.

Note that the logic of the alarm output signal 13 is normal when "0" and abnormal when "1".

〔The invention's effect〕

As described above, according to the present invention, the switching unit receives the switching control information from the two active systems and makes a logical decision based on the switching control information, so that the switching control system can be easily monitored. Moreover, there is an effect that the abnormality of the switching system can be easily determined.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of the present invention, in which (a) is a circuit block diagram, (b) is a circuit diagram of a switching unit, and FIG. 2 is a diagram showing a conventional technique. (a) is a circuit block diagram, and (b) is a circuit diagram. 1 switching unit 2 operating system A 3 operating system B

Claims (2)

(57) [Claims] An alarm signal is transmitted when a failure occurs, and when a switching control signal is received, switching to a normal operation system is performed, and the first and second operation systems return the switching control signal as switching control information; When the alarm signal is received from the second operating system, the switching control signal is output to the first and second operating systems to give an instruction to switch to the normal operating system, and is returned from the first and second operating systems. A switching control monitoring circuit comprising: a switching unit that detects a mismatch between the obtained switching control information and the switching control signal, and outputs an alarm output signal if the mismatch does not occur, and detects a switching abnormality of an operation system. 2. The switching control monitoring circuit according to claim 1, wherein the switching unit inputs an alarm signal from the first and second operating systems to a set input terminal and a reset input terminal, and switches to a normal operating system. A first flip-flop for outputting a switching control signal for switching to the first and second operating systems, and inputting switching control information returned from the first and second operating systems to a set input terminal and a reset input terminal. A second flip-flop for outputting a result; detecting a mismatch between the switching control and the switching control information from outputs of the first and second flip-flops; A switching control monitoring circuit having a logic element for detecting a system switching abnormality.