JPS6096043A - Fault supervising system of multiplex converter - Google Patents

Abstract

PURPOSE:To simplify circuit constitution and to improve reliability by supplying sequentially each input/output signal of an active and a spare multiplex converter to a common signal supervising circuit with a scanning signal to supervise the state of each input/output signal. CONSTITUTION:The input/output signal of multiplex converters 1, 2 is inputted sequentially to a signal supervising circuit 33 by opening sequentially gates 25-32 with the scan signal and supervised (e.g., supervision of presence of a frame signal). If a fault is detected to the input side signal system, since it is not a fault of the multiplex converters, the switching is inhibited. When no fault exists in the input side signal system and a fault is detected only at the output side signal system, relays rl1-8 are switched and the system is changed over to the spare system. In this case, a test signal generator 23 is connected to the active system so as to check the operation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a multiplex converter consisting of N working multiplex converters and one protection multiplex converter, in which all input and output signals of each multiplex converter are Monitoring is performed by a signal monitoring circuit provided in one-to-one correspondence with input and output signals.

FIG. 1 is a block diagram showing a monitoring method of a conventional multiplex converter such as NI. In the figure, in the backup multiplex converter 2, the test signal from the test signal generation circuit 19 is returned via the multiplex converter 2 and the relay contact R-2, and the signals obtained are converted into bipolar/unibo Times M(B
The operation of the standby multiplex converter is constantly monitored by monitoring circuits 19 to 22 via the /U converter circuits 7 to 10. Each input/output section of the current multiplex converter 1 is connected to B
The signals are supplied to signal monitoring circuits 15-18 via /U conversion circuits 3-6. Signal monitoring circuit 1 of current multiplex converter 1
When 5 to 18 detect a fault, relay contact r11
.about.8 is operated, and the backup multiplex converter is used for information signal transmission in place of the current multiplex converter. At this time, the test signal generation circuit 23 and the termination circuit 24 are connected to the low-speed input section of the current multiplex converter system in which the fault has been detected. In this state,
The signal from the circuit 23 is looped back to the circuit 24 via the relay contact rA'l, thereby checking the operation of the current multiplex converter system in which the fault has occurred.

However, such a conventional monitoring system requires signal monitoring circuits 15 to 22 for monitoring the transmitted and received signals, which increases the circuit scale and degrades reliability.

SUMMARY OF THE INVENTION An object of the present invention is to provide a monitoring method for a multiplex converter comprising one backup multiplex converter, which eliminates the above-mentioned drawbacks, in which each input/output signal of the working and backup multiplex converter is controlled by a scan signal. It is characterized in that the state of each input/output signal is monitored by sequentially supplying the signal to a common signal monitoring circuit.

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 2 is a block diagram showing an embodiment of the present invention, and shows a state in which the current multiplex converter 1 is used for information signal transmission.

In this embodiment, bipolar unibo 2 conversion circuits 3 to 1o having high input impedance and demultiplexer circuits 11λ to 14.1 installed on the high-speed signal side are used. 1, gate circuits 25.about.2zl, a signal monitoring circuit 33, and a scan signal generation circuit 34. Further, the preliminary multiplex converter 2 is connected to the test signal generating circuit 23 via the relay 117, and is connected to the relay r on the high speed side of the multiplex converter 2.
12 performs signal return, and the signal is terminated at a terminating resistor 24 via a relay R-8.

In FIG. 2, the input/output signals of the multiplex converters 1 and 2 are sequentially transmitted to the signal monitoring circuit 33 by sequentially opening gates 25 to 32 in response to scan signals. The signal is input and monitored (for example, the presence or absence of a frame signal is monitored). For example, if a fault is detected in the input side signal system, switching is prohibited since it is not a fault in the multiplex converter. Further, when there is no failure in the input side signal system and a failure is detected only in the output side signal system, the relays ri11 to ri8 are switched to the standby system.

At this time, the test signal generator 2j is connected to the current system and its operation is checked.

Further, when a failure in the backup system is detected in the operation check of the backup system, switching operation from the active system to the backup system is prohibited.

FIG. 3 is a block diagram showing the structure of the bipolar/unipolar converter. In the figure, the bipolar-unipolar converter 3 has a high impedance resistor 38 on the input side, so it hardly affects the bipolar signal sent from the multiplex converter to the transmission line. The signal attenuated through the resistor 38 is transferred to the bipolar-unipolar conversion circuit 3.
4 is converted into a unipolar signal by the amplifier circuit 35, the reproduction circuit 36, and the tuning circuit 37.As described above, in the present invention, the human output signal monitoring of a large number of multiplexing devices, which was conventionally required, is possible. Since the circuit can be changed to a single signal monitoring circuit, the circuit configuration is simplified and reliability is improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional monitoring system, FIG. 2 is a block diagram showing an embodiment of the present invention, and FIG. 3 is a block diagram showing a bipolar/unipolar converter. In FIGS. 1 to 3, 1 to 2...Multiple converter, 23...Test signal generation circuit, 15 to 22
...Signal monitoring circuit, 3 to 1o... Bipolar/unipolar conversion circuit, r no. 1 to 8...
Relay contact, ＼ 11~14...Demultiplexer circuit, 25~
32...Gate circuit, 33...Signal monitoring circuit, 34...Scan signal generation circuit, 24...
... Termination resistor, 28 ... Bipolar-unipolar conversion circuit, 35 ... Amplification circuit, 36 ...
... Reproduction circuit, 37... mark, tuning circuit.

Claims (1)

[Claims] In a monitoring method for a multiplex converter consisting of a plurality of working digital multiplex converters and one standby digital multiplex converter, the output signals of each of the working and standby multiple converters are sequentially shared by scan signals. A monitoring system for a multiplex converter, characterized in that the state of each input/output signal is monitored by supplying the signal to a signal monitoring circuit.