JPS63132543A - Monitoring system for multiplexer - Google Patents

Abstract

PURPOSE:To realize the profitability and simplification of a monitoring circuit by monitoring separately a lower order group input interface part, a multiplexing part, a higher order group output interface part, a higher order group input interface part, a demultiplexing part, and a lower order group output interface part, respectively. CONSTITUTION:An existing system multiplexer 17 and a stand-by multiplexer 18 are switched by changeover switches 19, 20, and these switches 19, 20 are operated by switching control signals 22, 23 outputted from a switching control part 21. In the switching control part 21, results of monitoring (signals 24-33) of the multiplexer 17 and 18 are inputted, and by these information, the existing system is switched to the stand-by system. That is, a detection of a fault of the multiplexer 17 of the existing system is executed, and when it is decided to be a fault, the system is switched. When a lower order group output signal disconnection or a higher order group output signal disconnection is detected, it is decided that the lower order group output interface concerned or the higher order group output interface has caused a fault.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multiplex converter monitoring system for monitoring whether the multiplex converter is operating normally.

[Conventional technology]

In order to improve the reliability of the system to which the multiplex converter is applied, it is necessary to monitor the device and, if an abnormality occurs, to immediately switch to a two-standby multiplex converter.

Conventional monitoring methods for multiplex converters include, for example, Japanese Patent Application Laid-Open No. 1983-
As described in Japanese Patent No. 59818, the input/output signals of the multiplex converter are branched and inputted to the monitoring device, and a switching circuit provided in the monitoring device selects a signal to be compared and verified.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take into consideration the mounting and economical aspects of the switching circuit for selecting the signals to be compared and verified, and there is a problem in that the monitoring device becomes large-scale and expensive.

In fact, for example, if a switching circuit is configured with a mechanical switch such as a relay, the scale of the circuit will increase and there will be problems in terms of service life (generally, switching occurs at a cycle of several tens of milliseconds to several hundred milliseconds, so relays (the number of operations is very large).

In addition, when an electronic switch is configured with a diode or transistor, it is necessary to switch high-frequency bipolar signals, so it is necessary to achieve flat frequency characteristics over a wide band and a small amount of crosstalk. It is difficult to configure and implement, and also requires expensive parts.

SUMMARY OF THE INVENTION An object of the present invention is to provide a monitoring method for a multiplex converter that can reliably detect faults without using a bipolar signal switching circuit.

[Problems and means to solve them]

The above purpose is to provide a low-order group manual interface unit that performs code conversion of low-order group input signals, a multiplexing unit that multiplexes code-converted signals of multiple channels, and a high-order group a that converts the code of the multiplexed signal and outputs it. a multiplexing device consisting of an interface section, a high-order group input interface section that performs code conversion of a high-order group input signal, a demultiplexer section that demultiplexes the output signal of the high-order group input interface section, and a demultiplexer section that converts the code of the demultiplexed signal and outputs it. A multiplexing/demultiplexing device comprising a low-order group output interface unit, wherein at least two of the multiplexing/converting devices are provided, and a changeover switch for switching one to a working system and the other to a standby system;
a comparison and collation unit that compares input and output signals of the multiplexing unit and the demultiplexing unit, a low-order group test signal generator, a high-order group test signal generator, a low-order group input signal disconnection detector, and a high-order group input A signal disconnection detector, a low-order group output signal disconnection detector, and a high-order group output signal disconnection detector are provided, and failures in the multiplexing section and the demultiplexing section are monitored by the comparing and checking section, and failures in the low-order group and Failures in the high-order group output interface section are monitored by respective output signal disconnection detectors, and when any of the input signal disconnection detectors detects a signal disconnection, the changeover switch switches to the standby multiplex converter, and the corresponding Input the corresponding next group of test signals from one of the test signal generators to the corresponding interface section of the multiplex converter, and check whether the input signal disconnection is detected again. This is accomplished by monitoring the other side for failures.

[Effect]

The low-order group input interface section, the multiplexing section, the high-order group output interface section, the high-order group input interface section, the demultiplexing section, and the low-order group output interface section constituting the multiplex conversion device are individually monitored, and the input interface section Since the monitoring method is capable of distinguishing between failures on the other side and failures on the other side, reliable failure detection can be achieved with the addition of relatively simple hardware.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a multiplex conversion device to which a monitoring system according to an embodiment of the present invention is applied. In FIG. 1, a working multiplex converter 17 and a standby multiplex converter 18 are provided between two changeover switches 19 and 20 that are controlled by control signals 22 and 23 from the switching control unit 21. ing.

In addition, the low-order group test signal 35 from the low-order group test signal generator 34 is input to the changeover switch f19, and the high-order group test signal 37 from the high-order group test signal generator 36 is input to the changeover switch 20. Further, a comparison/verification section 52 is provided, the details of which will be discussed later.

Two multiplex converters 17, one for active system and one for backup system. i8 have the same configuration, and each converts the code of the low-order group input signal inputted via the switching input 'f19 (for example, converting from a bipolar code to a unipolar code, hereinafter referred to as B/Ll conversion). Next group input interface units 2 and 3, a multiplexing unit 4-5 that multiplexes the signals that arrive from a plurality of channels and have undergone the conversion, code conversion of the multiplexed signals (for example, conversion from unipolar code to bipolar code, Below U
/B conversion) and a multiplexing device consisting of high-order group output interface units 6 and 7 that output via a switching switch 20; and a high-order group input interface that performs code conversion of a high-order group input signal input via a changeover switch 20. Part 10. It consists of a demultiplexing section 12.13 that demultiplexes the output signal of the interface section 10.11, and a low-order group output interface section 14.15 that converts the code of the demultiplexed signal and outputs it via the changeover switch 19. It consists of a demultiplexer and a demultiplexer.

Low-order group input signal disconnection detection signals 24 and 25 detected by the low-order group input interface sections 2 and 3, high-order group input signal disconnection detection signals 26 and 27 detected by the high-order group input interface section 10.11, and low-order group output Interface part 14.15
The low-order group output signal disconnection detection signals 28 and 29 detected by the high-order group output interface sections 6 and 7 and the high-order group output signal disconnection detection signals 30 and 51 detected by the high-order group output interface sections 6 and 7 are given to the switching control section 21. In addition, the comparison and matching section 32 includes each multiplexing section 4.5.
and the input/output signals of the demultiplexing section 12.13 are input, and the comparison and verification result 53 is given to the switching control section 21.

FIG. 2 is a detailed configuration diagram of the low-order group input interface section 2. As shown in FIG. Same and other low and high order group input interface parts 3 and 1
0.11 also has the same configuration.

In the second factor, 58 is an i equalizer, 59 is a peak detector, 40 is a B/[1 converter, and 41 is a discriminator.

42 is a low-order group signal, 43 is a timing extractor, 44 is an extraction clock, and 45 is a clock interruption detector. The low-order group input signal 1 is equalized by the θ equalizer 38 and then converted into a unipolar code by the B/EJ converter 40. Also, at this time, a peak is detected by the peak detector 39, and feedback control is performed to the circuit 38. A timing extractor 43 extracts a clock from the output of the circuit 40, and the extracted clock is used for discrimination in a discriminator 4 and 2, and a low-order group signal 42 in a unipolar code format is output. The extracted clock is detected to be disconnected by a clock disconnection detector 45, and the result is outputted as a signal 24.

As is well known, the tallock disconnection detector 45 can be easily and inexpensively realized using a mono-multivibrator.

FIG. 5 is a detailed configuration diagram of the low-order group output interface section 14. The same and other low-order and high-order group output interface sections 15
, 6.7 also have the same configuration.

In FIG. 5, numeral 46 is a low-order group output signal in unipolar code format, 47 is a transmission clock, 48 is a retiming circuit, 49 is a U/B conversion circuit, and 50 is a tarlock break detection circuit. The low-order group output (j number 46 is retimed in a circuit 48 by a transmission clock 47, converted into a bipolar signal in a circuit 49, and becomes an output signal 16. At this time, the circuit 50 detects a clock disconnection. The circuit 50 can be easily and inexpensively implemented using a mono-multivibrator or the like.

FIG. 4 is a detailed configuration diagram of the comparison and matching section 32.

In FIG. 4, 51 is a low-order group input/output signal, 52 is a selection circuit, 53 is a comparison/verification circuit, 54 is a selection circuit, 55 is a demultiplexer, 56 is a selection circuit, and 57 is a high-order group input/output signal. First, the low-order group input/output signal 5 in unipolar code format
1, the selection circuit 52 selects the signal to be compared;
It is output to the comparator 53. On the other hand, from the unipolar code format high-order group input/output signal 57, a selection circuit 56 selects a signal to be compared, and a selection circuit 56 demultiplexes the signal. The operation of circuit 55 is the same as circuit 12. From the separated signals, a selection circuit 54 selects a low order group signal to be compared and outputs it to a comparator 55. The comparator 53 matches the phases of the low-order group signals inputted from both of them, performs comparison and verification, and outputs the result 35. The selection circuits 52 and 56 are
Since the input signal is in the unipolar code format, it is easy and inexpensive (two configurations are possible, and it is also possible to implement the entire system as an LSI), making it possible to realize a cheaper and more reliable comparative diagnosis section.

The operation of the system having such a configuration will be explained next.

Now, the switching input f19.20 is the active multiplex converter 11.
7, first, the low-order group input signal 1 is input to the low-order group input interface section 2 through the switching switch f19, and after being code-converted there, it is sent to the multiplexing section 4. is input. In the multiplexing unit 4, each of the plurality of signals inputted in this way (2) is synchronized with each other (stuff), and
The two synchronized signals are time-division multiplexed according to certain rules, converted into higher-order group signals, and output. This high-order group signal is code-converted by the high-order group output interface section 6, and the high-order group output signal 8 is outputted through the changeover switch 20. In this way, the multiplexing device comprising the circuits 2, 4, and 6 performs an operation of time-division multiplexing a plurality of low-order group signals, converting them into high-order group signals, and outputting the same.

Conversely, the demultiplexer consisting of circuits 10, 22, and 14 is
It operates to demultiplex a high-order group signal into a plurality of low-order group signals. That is, the high-order group input signal 9 is inputted to the high-order group input interface section 10 through the changeover switch 20, and is then subjected to sign conversion (for example, B/[1 conversion) by the circuit 10 (second step).
This converted high-order group signal is subjected to frame synchronization in the demultiplexing unit WI112, and based on the frame synchronization pulse, it is divided into a plurality of low-order group signals (separated into two, and the separated low-order group signals are Each signal is destuffed, and the jitter caused by the destuffing is absorbed by the phase-locked loop and output.These low-order group signals are code-converted (for example, IJ/B conversion) in the low-order group output interface section 14. Then, the low-order group output signal 16 is output through the changeover switch 19.The operation of the standby multiplex converter 18 is also the same as described above, but the low-order group test signal generator is used as the low-order group input signal. 34
The low-order group test signal 55 output from the high-order group test signal generator 36 is input as the high-order group input signal, and the high-order group test signal 37 output from the high-order group test signal generator 36 is input as the high-order group input signal.

Switching between the active multiplex converter 17 and the backup multiplex converter 18 is performed by a changeover switch f9.20+2, and these switches 19.20 are operated by a changeover control signal 22.25 output from the changeover control unit 21. Operate. The monitoring results of the multiplex converters 17 and 18 (signals 24, 25° 26, 27, 28, 29, 30, 51 .
! 55) are input, and switching from the active system to the backup system is performed from these information (2).In other words, if a fault in the active system multiplex converter 17 is detected and determined to be a fault ( Second, system switching is performed.If a low-order group output signal disconnection or a high-order group output signal disconnection is detected, the corresponding low-order group output interface or high-order group output interface is determined to be a failure.Low When a disconnection of the next group input signal or a disconnection of the higher order group input signal is detected (Secondly, first, switch the input channel from the active system to the backup system with the changeover switch 19 or 20, and connect the input interface where the input disconnection of the active system was detected. The test signal 55 or S7 is inputted to the input terminal 1, and it is monitored whether or not an input disconnection is detected again.

If the input disconnection is detected again at this time, it is determined that the input signal is normal, and the corresponding input interface section is determined to be at fault. If this input disconnection is not detected, it is determined that the relevant interface unit is normal, and the fault is in the other party's equipment or trunk line, so the switch is switched back based on the channel.

The comparison/verification section 32 performs bit verification of the input/output signals of the multiplexing sections 4, 5 and demultiplexing sections 12, 13, or compares the results of counting the number of marks.

Therefore, when the comparing unit 5!1 indicates a mismatch between the input and output signals, it is determined that the corresponding circuit is at fault.

Incidentally, the protection multiplex converter 18 is also monitored in the same manner. This is to prevent switching to the backup system if there is an input disconnection, an output disconnection, or if the comparison result shows that the input/output 4 does not match the number in the backup system. Similarly, after switching from the backup system to the active system, the above-mentioned operation monitoring of the active system is performed.

According to this embodiment, input signal disconnection detection is performed by detecting disconnection of the clock extracted from the input signal, and output signal disconnection detection is performed by detecting disconnection of the transmission clock. It is well known that these clock disconnection detections can be easily configured using, for example, a mono-multivibrator. In addition, since the input/output signals of the multiplexing unit and demultiplexing unit, which are the targets of comparison, are unipolar codes, the switching circuit for selecting these is a logic I
It can be easily constructed using C, and it is also possible to implement this comparison and verification section into an LSI.

As mentioned above, each part for monitoring the multiplex conversion device is
It can be easily constructed using inexpensive parts, and since the entire switching device is monitored multiple times, failures can be detected reliably.

〔Effect of the invention〕

According to the second invention, it is possible to reliably detect a fault in a multiplex converter without using a bipolar signal switching circuit.
This has the effect of making the monitoring circuit economical and simple.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention (=a configuration diagram of a multiplex conversion device to which such a monitoring system is applied, the second factor, and FIG. 3. FIG. 4 shows the low-order group input interface section shown in FIG. , a detailed configuration diagram of a low-order group output interface section, and a comparison/verification section. 2... Low-order group input interface section, 4... Multiplexing section, 6... High-order group output interface section, 10...
High-order group input interface section, 12... demultiplexing section,
14... Low-order group output interface section, 17... Active system multiplex conversion device, 18... Backup system multiplex conversion device, 3
8...θ equalizer, 40...B/[3 converter, 41...
...Discriminator, 43...Timing extractor, 45...
Clock disconnection detector, 48... Retiming circuit, 49
... [1/B converter, 50... clock disconnection detector,
51...Low-order group input/output signal, 52...Selection circuit, 5
3... Comparison verification circuit, 54... Selection circuit, 55...
- Demultiplexer, 56... Selection circuit, 57... High-order group input/output signal. Agent Patent Attorney Katsuo Ogawa 2u Figure 2 Figure 3 38° f'@IaM 4B? ('>71 Yut
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Claims (1)

[Claims] 1. A low-order group input interface section that performs code conversion of a low-order group input signal, a multiplexing section that multiplexes the code-converted signals of multiple channels, and a high-order group output interface section that converts the code of the multiplexed signal and outputs it. a high-order group input interface unit that performs code conversion of a high-order group input signal, a demultiplexer unit that demultiplexes the output signal of the high-order group input interface unit, and a low-order group unit that converts the code of the demultiplexed signal and outputs it. A multiplexing/demultiplexing device comprising an output interface section, at least two of the multiplexing/converting devices are provided, and a changeover switch for switching one to a working system and the other to a standby system, and the multiplexing section and the demultiplexing device. a comparison/verification section for comparing respective input/output signals of the section, a low-order group test signal generator, a high-order group test signal generator, a low-order group input signal disconnection detector, a high-order group input signal disconnection detector, and a low-order group test signal generator; A next group output signal disconnection detector and a high order group output signal disconnection detector are provided, failures in the multiplexing section and demultiplexing section are monitored by the comparing and checking section, and failures in the low order group and high order group output interface sections are monitored. Each output signal disconnection detector monitors the output signal, and when any of the input signal disconnection detectors detects a signal disconnection, the changeover switch switches to a standby multiplex converter, and the corresponding interface of the multiplex converter is switched. inputting a corresponding next group of test signals from one of the test signal generators to the interface unit, and monitoring whether the interface unit itself is at fault or the other side is at fault, depending on whether an input signal disconnection is detected again. A monitoring method for a multiplex conversion device characterized by: