JP2586803B2 - Selector monitoring circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a selector monitoring circuit, and more particularly to a selector monitoring circuit that monitors whether a selector control signal is transmitted to a selector circuit normally.

[0002]

2. Description of the Related Art In general, a conventional selector monitoring circuit includes:
The main purpose is to monitor whether the operation of the selector circuit is normal.

FIG. 2 is a block diagram showing an example of a conventional selector monitoring circuit.

Referring to FIG. 2, a selector monitoring circuit comprises:
A path pattern insertion unit 7 including a fixed path pattern insertion circuit 10 for providing the same fixed code information to n (n is an integer of 2 or more) main signals, and a control unit including a control signal generation circuit 4 for generating a selector control signal 2, a selector circuit 3 for controlling an arbitrary one of the n main signals input according to the selector control signal transmitted from the control unit 2, and a specific portion of the selected one main signal. And a selector unit 1 including a path pattern monitoring circuit 9 for extracting and verifying the code information in FIG.

In operation, the fixed path pattern insertion circuit 10 in the path pattern insertion section 7 inserts the same fixed code information into n main signals. The control signal generation circuit 4 in the control section 2 sends a selector control signal for selecting one of the n main signals to the selector circuit 3, and the selector circuit 3 receives the n main signals by this signal. One specific signal is selected from the signals and output.

The path pattern monitoring circuit 9 takes out a path pattern inserted into a specific portion from one main signal selected by the selector circuit 3 and compares whether or not it matches predetermined information. If not, issue an alarm.

[0007]

As described above, the conventional selector monitoring circuit can monitor whether the main signal passing through the selector circuit is normal and output an alarm, but the alarm is output to the selector circuit. During transmission of the bus line or the like from the control unit to the selector unit, as a result of a failure for some reason, the selector circuit selects a main signal different from the main signal to be originally selected due to abnormality of the selector control signal. It cannot be monitored if it has.

An object of the present invention is to monitor the failure of the selector circuit itself, and at the same time, match the selector control signal input to the selector circuit with the signal output from the selector control signal generation circuit, so that the selector circuit originally selects. An object of the present invention is to provide a selector monitoring circuit capable of monitoring whether a main signal to be selected is selected.

[0009]

SUMMARY OF THE INVENTION A selector monitoring circuit according to the present invention is a monitoring circuit for a selector circuit in which a plurality of selected signals are selectively derived by a selection control signal. Means for adding different unique information at the preceding stage of the selector circuit, and comparing means for comparing the unique information added to the selected signal selected by the selector circuit with the selection control signal, The selector circuit is monitored based on the comparison result.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of the present invention. In FIG. 1, components having the same reference numerals as those in FIG. 2 indicate that they are the same as those in the conventional example. The selector control signal monitoring circuit shown in FIG.
n, a pass pattern decode circuit 5 and a comparison circuit 6.

The operation of the circuit shown in FIG. 1 will be described. The path pattern insertion circuits 81 to 8n in the path pattern insertion unit 7 insert unique code information into the main signals 1 to n, respectively.

The control signal generation circuit 4 in the control section 2 sends a selector control signal to the selector circuit 3 in the selector section 2 and sends a similar selector control signal to the comparison circuit 6 in the control section 2.

The selector circuit 3 outputs one of the n main signals based on the received selector control signal.
Select and output a book.

The pass pattern decoding circuit 5 extracts unique information included in the main signal output from the selector circuit 3, converts it into a selector control signal corresponding to this information, and sends it to a comparison circuit 6 in the control unit 2. .

In the comparison circuit 6, the pass pattern decoding circuit 5
Control signal and control signal generation circuit 4 sent from
Is compared with the selector control signal sent directly from the controller to verify whether they match.

Normally, if the selector circuit 3 and the control signal between the control unit 2 and the selector unit 1 are normal, the selector circuit 3
In the comparison circuit 6, since the selector control signal generated in the control section 2 matches the selector control signal converted in the selector section 1, no alarm is issued.

On the other hand, when the selector control signal between the control unit 2 and the selector unit 1 becomes abnormal, the selector circuit 3 outputs the main signal of a unit different from the selector control signal output from the control signal generation circuit 4. Select and output. The pass pattern decoding circuit 5 converts the unique information in the erroneously selected main signal into a selector control signal and sends it to the comparison circuit 6 in the control unit 2.

For this reason, when the values of the selector control signals received from the two locations are compared by the comparison circuit 6, they always become inconsistent, so that an alarm is issued. Although the pass pattern decoding circuit 5 decodes the unique information in the main signal, the pass pattern decoding circuit 5 may decode the selector control signal and compare it with the unique information in the main signal by the comparison circuit 6.

[0020]

According to the present invention, since the unique code information is inserted in each of the n main signals to be selected, the failure of the selector circuit itself is monitored, and at the same time, the selector input to the selector circuit is monitored. It is also possible to check whether the control signal matches the signal output from the selector control signal generation circuit.

[Brief description of the drawings]

FIG. 1 is a block diagram of the present invention.

FIG. 2 is a block diagram showing a conventional example of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Selector part 2 Control part 3 Selector circuit 4 Control signal generation circuit 5 Path pattern decoding circuit 6 Comparison circuit 7 Path pattern insertion part 81-8n Path pattern insertion circuit

Claims (2)

(57) [Claims] 1. A monitoring circuit for a selector circuit, which selectively derives a plurality of signals to be selected by a selection control signal, wherein different information unique to each of the selected signals is provided in a preceding stage of the selector circuit. Means for adding, and comparing means for comparing the unique information added to the selected signal selected by the selector circuit with the selection control signal, and the selector circuit is monitored based on the comparison result. A selector monitoring circuit characterized in that: 2. The selector monitoring circuit according to claim 1, wherein said comparing means performs a comparison process after converting said unique information into the same signal information as said selection control signal.