JPH02105647A - Line supervisory system - Google Patents

Abstract

PURPOSE:To easily detect a line fault in bidirectional communication by sending a supervisory signal to a first line after multiplexing on an information signal, sending the supervisory signal detected from a multiplex signal to a second line after multiplexing on the information signal, and comparing and judging those supervisory signals at a comparison judging circuit. CONSTITUTION:The part of an M group signal (a) is extracted from the multiplex signal (d) inputted to a communication equipment 1 by the comparison judging circuit 8, and the part of the information signal (f) is outputted to an output terminal 14. The comparison judging circuit 8 extracting the M group signal (a) from the multiplex signal (d) inputs the M group signal (a) corresponding to an extracted M group signal (a) from an accumulation circuit 7, and compares those M group signals with each other. When a fault occurs in either a line 3 or 4, it is judged that a code error exists in the M group signal (a) extracted from the multiplex signal (d). Therefore, the M group signal (a) from the accumulation circuit 7 does not coincide with the M group signal (a) from the multiplex signal (d). At this time, the circuit 8 judges that the code error exists, and outputs a judging signal (e) representing the code error of the M group signal (a) from the multiplex signal (d). Thus, it is possible to supervise the fault in the lines 3 and 4 in the communication equipment 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a line monitoring system for failures in signal lines transmitted through a plurality of devices.

[Conventional technology]

In general, line monitoring systems monitor and correct code errors in information caused by line failures.

In conventional line monitoring systems, a line for transmitting information is divided into a plurality of sections, and each section, for example between repeaters, is monitored. Specifically, line failure information for each section is collected in one place, such as a main supervisory control device, and monitored by this main supervisory control device, thereby performing code error correction for each section.

[Problem to be solved by the invention]

The conventional line monitoring method described above monitors each section of the line,
Since the system adopts a method of collecting line failure information for each section in one device such as the main supervisory control device, a device for collecting line failure information from each section and transmitting it to the main supervisory control device etc. It has the disadvantage of requiring

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide an economical line monitoring system that can monitor the entire line section with a simple configuration.

[Means to solve the problem]

The present invention provides a first communication device provided with a monitoring signal generation circuit, a first selection circuit, and a comparison/judgment circuit, and a second communication device provided with a monitoring signal detection circuit and a second selection circuit. A line monitoring method for monitoring line failures by sending a monitoring signal to first and second lines for bidirectional communication connecting between the first and second lines, the first selection circuit comprising: The monitoring signal from the communication signal generating circuit is multiplexed into an information signal to the second communication device and sent to the first line, and the monitoring signal detection circuit is configured to multiplex the information signal to the second communication device and send it to the first line. A monitoring signal is detected from the multiplexed signal from the monitoring signal and sent to the second selection circuit, and the second selection circuit detects the monitoring signal from the monitoring signal detection circuit from the first detection circuit. The information signal is multiplexed with the information signal to the communication device and sent to the second line, and the comparison/judgment circuit detects the monitoring signal from the multiplexed signal from the second selection circuit, and detects the monitoring signal from the multiplexed signal from the second selection circuit. The present invention is characterized in that the presence or absence of a line fault is determined by comparing the monitoring signal and the monitoring signal generated in the monitoring signal generation circuit.

〔Example〕

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

FIG. 1 is a block diagram showing a line monitoring system according to an embodiment of the present invention.

The line monitoring method of this example is a method for monitoring failures in lines 3 and 4 for bidirectional data communication between communication devices 1 and 2 by loop transfer of M-sequence signal a.

The communication device 1 includes an M-sequence signal generation circuit 5, a selection circuit 6, an accumulation circuit 7, and a comparison/determination circuit 8.

The M-sequence signal generation circuit 5 is a circuit that generates an M-sequence signal a for monitoring and outputs it to the selection circuit 6 and the storage circuit 7.

The selection circuit 6 is a circuit that multiplexes the information signal from the input terminal 9 and the M-sequence signal a from the M-sequence signal generation circuit 5 and outputs the multiplexed signal C to the line 3. Specifically, the M-sequence signal a is low-speed multiplexed into an unused time slot of the information signal S which is input to the selection circuit 6 at a predetermined time slot.
(multiplexed at a ratio of 1), and the multiplexed signal C is sent to line 3.
This is a circuit that sends the data to the communication device 2 side via.

The accumulation circuit 7 accumulates the M-sequence signal a from the M-sequence signal generation circuit 5, and selects a predetermined M-sequence signal a from among the accumulated M-sequence signals a under the control of the comparison and judgment circuit 8. This is a circuit that outputs to.

The comparison/judgment circuit 8 extracts and inputs the M-sequence signal a from the multiplexed signal d input to the communication device l via the line 4, and converts this M-sequence signal a into the M-sequence signal a from the storage circuit 7. This circuit determines the presence or absence of a code error due to a fault in the line 3.4 by comparing the 3.4 and 3.4, and outputs a determination signal e indicating the presence or absence of a code error.

The communication device 2 includes an M-sequence signal detection circuit 10 and a selection circuit 11.
It is equipped with

The M-sequence signal detection circuit 10 is a circuit that detects an M-sequence signal a from the multiplexed signal C input via the line 3 and outputs the M-sequence signal a to the selection circuit 11.

The selection circuit 11 is a circuit having the same function as the selection circuit 6 of the communication device 1. That is, the M-sequence signal a from the M-sequence signal detection circuit 10 is multiplexed at a low speed into an unused time slot of the information signal f input from the input terminal 12 at a predetermined time slot, and the multiplexed signal d is sent via the line 4. It has the function of transmitting the information to the communication device l.

Next, the operation of this embodiment will be explained.

When an information signal is input from the input terminal 9 of the communication device 1 to the selection circuit 6 at a predetermined time slot, the selection circuit 6 selects an unused time slot of the information signal and outputs the M sequence from the M sequence signal generation circuit 5. Signal a is low-speed multiplexed into the unused time slot and output as multiplexed signal C to line 3. At this time, the storage circuit 7 accumulates the M-sequence signal a from the M-series signal generation circuit 5 over time.

The multiplexed signal C output from the selection circuit 6 of the communication device J is input to the communication device 2, and the M-sequence signal detection circuit 10 extracts the M-sequence signal a portion.

Therefore, a portion of the information signal is outputted to the output terminal 13.

M detected and extracted by the M-sequence signal detection circuit 10
The series signal a is output to the selection circuit 11 and input terminal 12
The information signals f& input from the 1st and 2nd terminals are low-speed multiplexed.

A multiplexed signal d formed by multiplexing the M-sequence signal a in the selection circuit 11 is input to the communication device 1 via the line 4 .

The multiplexed signal d input to the communication device 1 is sent to the comparison/judgment circuit 8
The M-sequence signal a portion is extracted, and the information signal f portion is output to the output terminal ]4.

The comparison/judgment circuit 8 that has extracted the M-sequence signal a from the multiplexed signal d receives the M-sequence signal a corresponding to the extracted M-sequence signal a from the storage circuit 7, and compares these M-sequence signals.

If no fault has occurred in lines 3 and 4, there is no code error in the M-sequence signal a extracted from the multiplexed signal d. Therefore, the M-sequence signal a from the storage circuit 7 and the M-sequence signal a from the multiplexed signal d match.

At this time, the comparison and determination circuit 8 determines that there is no code error,
A determination signal e indicating this is output.

If either line 3 or 4 is faulty,
There is a code error in the M-sequence signal a extracted from the multiplexed signal d. Therefore, the M-sequence signal a from the storage circuit 7 and the M-sequence signal a from the multiplexed signal d do not match. At this time, the comparison/determination circuit 8 determines that there is a code error, and outputs a determination signal e indicating the code error in the M-sequence signal a from the multiplexed signal d.

In this way, in this embodiment, failures in the lines 3 and 4 can be monitored within the communication device 1.

〔Effect of the invention〕

As explained above, in the line monitoring system of the present invention, the first communication device multiplexes the monitoring signal into an information signal and sends it to the first line using the first selection circuit, and the second communication device ,
A configuration in which a monitoring signal detected from this multiplexed signal is multiplexed into an information signal by a second selection circuit and sent to a second line, and this monitoring signal is compared and determined by a comparison and determination circuit of the first communication device. As a result, line failures in bidirectional communication can be easily detected by adding a small amount of circuitry, without requiring equipment to collect and transmit failure information from each section as in conventional line monitoring systems. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a line monitoring system according to an embodiment of the present invention. ■... Tsushin W (first communication device) 2... Communication device (second communication device) 3... Line (first line) 4... Line (second line) 5 ...M series signal generation circuit (monitoring signal generation circuit) 6...Selection circuit (first selection circuit) 8...Comparison/judgment circuit 10...M series signal detection circuit (monitoring signal detection circuit) )

Claims (1)

[Claims] (1) A first communication device provided with a monitoring signal generation circuit, a first selection circuit, and a comparison/judgment circuit, and a second communication device provided with a monitoring signal detection circuit and a second selection circuit. The first and second lines for two-way communication connecting between
A line monitoring method that monitors line failures by sending out a monitoring signal, wherein the first selection circuit converts the monitoring signal from the monitoring signal generation circuit into information to the second communication device. The monitoring signal detection circuit detects the monitoring signal from the multiplexed signal from the first selection circuit and sends it to the first line. The second selection circuit multiplexes the monitoring signal from the monitoring signal detection circuit into an information signal to be sent to the first communication device and sends the information signal to the second line. , the comparison and determination circuit is
A monitoring signal is detected from the multiplexed signal from the second selection circuit, and the monitoring signal is compared with the monitoring signal generated in the monitoring signal generation circuit to determine the presence or absence of a line failure. A line monitoring method characterized by: