JPH01162439A - Method for detecting cable trouble - Google Patents

Abstract

PURPOSE:To surely detect at which data line a trouble occurs by coupling a transmission side multiplexing device provided at a transmission side and a reception side multiplexing device provided at a reception side with a cable trouble supervising exclusive-use line having a comparator at the reception side and shifting and comparing the data at a transmission/reception side while they are synchronized. CONSTITUTION:Data A-H to be transmitted are successively shifted by a transmitting side multiplexing device 1, transmission data J are prepared, and sent to a cable trouble supervising exclusive-use line. By synchronizing with the transmission data and successively shifted by a receiving side multiplexing device 2 in the same way as the transmission side from received data A-H at the receiving side, reception data J' are prepared, data J and J' are compared with a comparator 3 provided at a reception side. At the time of coincidence, the trouble of a data line is not present, at the time of the dissidence, it is decided that a trouble is present and a trouble line is specified in accordance with the shifting sequence. Thus, it is found at once which data line is troubled and the execution of the trouble countermeasure can be rapidly performed.

Description

[Detailed Description of the Invention] [Summary] In a cable failure detection method when data is transmitted and received between switching equipment via a trunk cable consisting of a plurality of data lines, For the purpose of confirming normality, there is a multiplexer on the transmitting side that sequentially shifts and multiplexes the transmitted data and sends it to the cable fault monitoring dedicated line, and a multiplexing device on the receiving side that synchronizes the received data of each data line with the transmitting side. It consists of a multiplexing device that sequentially performs shift multiplexing, and a comparator that compares the data sent through the dedicated cable fault monitoring line with the data from the receiving side multiplexing device on the receiving side.

[Industrial application field]

The present invention relates to a cable failure detection method when data is transmitted and received between switching equipment via a trunk cable consisting of a plurality of data lines.

Generally, the connection cable between exchange equipment is plugged into the equipment side terminal board on the east line using a 50-pin connector or the like. Therefore, if the connector plug is inserted incorrectly, data may not be transmitted normally from the transmitting side to the receiving side. Furthermore, even if a part of the connecting cable is disconnected, the data will lose its normality. Particularly in recent years, digital signals are being used to transmit and receive data, so a bit transmission failure immediately affects data transmission. Various methods are used to detect these cable faults.

[Conventional technology]

A conventional cable fault detection method is shown in FIGS. 4 and 5.

The method shown in Fig. 4(a) is based on the connection cable bundle between devices.
This is a method in which a monitoring line dedicated to monitoring the cable is provided, and if a cable disconnection occurs, the monitoring circuit on the receiving side immediately detects the failure. Figure 4 (b
) shows an example of a monitoring circuit. In the figure, the monitoring circuit wall normally monitors the grounding on the transmitting side and sets it to "L" level, and when the cable is disconnected or disconnected, the receiving side changes to "H" level, which is reversed by the inverter circuit and set to "L" level. The L'' level is applied to the light emitting diode LED, the LED operates, and a fault detection signal is transmitted.

The method shown in Figure 5(a) is that when transmitting and receiving data using digital signals, if there is an empty channel on that line, a specific pattern is inserted into that empty channel and transmitted, and the receiving side uses this specific pattern. In this method, the pattern is extracted by an extraction circuit, compared with a specific pattern by a pattern comparison circuit, and if it is not the same, it is detected as a failure. FIG. 5(h) shows an example of a pattern comparison circuit. In the figure, if an 8-bit monitoring bit, for example "01010101", is provided as a specific pattern in one channel of the 24-channel periodic transmission data, then the receiving side extracts this specific pattern and registers it in the shift register of the pattern comparison circuit. The launch circuit once lies, the inverter circuit inverts the O level, the AND circuit detects 1, and the "H" level signal is sent to the detection circuit, confirming that the data is normal. Make sure that. “L” if the specific pattern does not match
The signal is sent to the level signal detection circuit and determined to be a failure.

[Problem that the invention seeks to solve]

The method shown in Figure 4 above is only effective for disconnecting connectors when connecting devices as east lines when there are multiple data lines, and the method shown in Figure 5 is used if there are no empty channels. There is also the problem that even if there is an empty channel, only a fault in that line can be detected.

Therefore, the present invention provides a method for monitoring all data lines for faults and detecting cable faults.

[Means for solving problems]

FIG. 1 shows a diagram of the principle of the present invention. In the figure, 1 is a transmitting side multiplexer that sequentially shift-multiplexes the transmitted data and sends it to the cable fault monitoring dedicated line on the transmitting side, and 2 is a receiving side that shift-multiplexes the received data of each data line in synchronization with the transmitting side. 3 indicates a comparator that compares the data sent through the dedicated cable fault monitoring line with the data from the receiving multiplexer on the receiving side.

[Effect]

There are data A-H to be transmitted, and these transmitted data A
~H are sequentially shifted by the transmitting side multiplexer 1 to create transmission data J, and sent to the cable fault monitoring dedicated line. On the receiving side, similarly to the transmitting side, the receiving side multiplexer 2 creates received data J' which is sequentially shifted in synchronization with the transmitted data from the received data A-H. A comparator 3 on the receiving side compares the received data J and J', and if they match, it is determined that there is no fault in the data line, and if they do not match, it is determined that there is a fault. For example, if there is a fault in the data line B, the comparator 3 detects a mismatch at the shift data position of B and detects a fault in the B line.

The present invention will be explained in detail with reference to FIG.

The transmission data is 8 lines A, 'B, C, D, E, F, G, and H, the output data of the transmitting side multiplexer 1 is J, and the output data of the receiving side multiplexer 2 is J゛. .

Note that the 8-bit transmission data A is A-1, A-2, ---
---A-9, A-10----1 Sending data B is B-
1, B-2, -------B-9. B-10-1
Similarly, H is H-1,)I-2,----11
-9, H-10----.

Output data J of the transmitting side multiplexer 1 is transmitted data A-
Take out channels one by one from H, 8-1, B-2
, C-3, D-4, E-5, F-6, G-7, H-8,
The transmission data of A-9 and B-10 is sent to the cable fault monitoring dedicated line.

If there is no cable fault, the output data J' of the receiving multiplexer 2 will be the same as the output data J, so the comparator 3 will not detect any fault.

If there is a fault in part of the data line, for example, if there is a fault in the B line, the data on B-2 and B-10 will disappear and output data J' will be sent out. 3
It is detected that the B data line is at fault by comparing the numbers.

〔Example〕

A circuit diagram of an embodiment of the multiplexing device and comparator of the present invention is shown in FIG.
Shown in a) and (b). The multiplexer performs an AND operation on data A-H and shift data ■ to ■, inserts the output of each AND circuit into an OR circuit, and outputs data J or Jo.
Take out. For example, if data 8 and ■ are "H", data A-4 is taken out by the AND circuit, and other data are not taken out. Next, data B and ■ become “°H”,
Data B-2 is taken out by the AND circuit. Therefore, data A- is sent to the OR circuit according to shift data ■ to ■.
H is taken out, A-1, B-2, C-3, D-4, E
-5, F-6°G-7, old total --- Output data J is sent from the OR circuit to the cable failure detection line in the order of -5, F-6°G-7, old total. By repeating the shift data, the data is sent out repeatedly in sequence. The multiplexer can use the same circuitry on both the transmitter and receiver sides.

As shown in FIG. 3(b), the comparator inserts data J and Jo into the EXOR circuit, and if J and J" match, "
"L" signals are sequentially sent out. By ANDing this signal with the shift data of ■ to ■, the "L" signals are sequentially inserted into the respective RS launch circuits as "H" signals through the inverter. The “H” signal at the S terminal and the “L” signal at the R terminal send an “L” signal to the Q terminal, the launch circuit is reset, and the data is determined to be normal.If the data J and Jo If there is a point where the numbers do not match, an "H" signal is sent from the EX OR circuit, and the AND with the corresponding shift data becomes an "H" signal, and a "L" signal is momentarily applied to the R terminal of the corresponding launch circuit. Then, an "H" signal is sent from the Q terminal, the launch circuit is set, and faulty data is detected.Therefore, it is detected which data line has the faulty data, and countermeasures against the fault are taken accordingly. I can do it.

〔Effect of the invention〕

As described above, according to the present invention, when transmitting and receiving data between devices, data on each data line is sequentially shifted and placed on one fault monitoring dedicated line, so that when a fault occurs in the data line, which It can detect whether there is a problem with the data line,
It is possible to take appropriate measures against failures.

[Brief explanation of the drawing]

Fig. 1 is a diagram of the principle of the present invention, Fig. 2 is an explanatory diagram of the principle of the present invention, Figs. 3 (a) and (b) are examples of circuit diagrams of a multiplexer and a comparator, and Fig. 4 (a) ) and (b) show a conventional method and circuit diagram, and FIGS. 5(a) and 5(b) show a second conventional method and circuit diagram. In the figure, 1 is a transmitting side multiplexer, 2 is a receiving side multiplexer, and 3 is a comparator.

Claims (1)

[Claims] A method for detecting cable faults when transmitting and receiving data between switching equipment via a trunk cable consisting of a plurality of data lines, which monitors cable faults by sequentially shifting and multiplexing transmitted data on the transmitting side. A transmitting side multiplexing device (1) that sends data to the dedicated line, a receiving side multiplexing device (2) that shifts and multiplexes the received data of each data line in synchronization with the transmitting side on the receiving side, and a dedicated cable fault monitoring device. It is equipped with a comparator (3) that compares the data sent through the line and the data from the receiving multiplexer on the receiving side, and the data on all data lines is sequentially shifted and extracted by the multiplexer. A cable failure detection method characterized by comparing and monitoring data on the transmitting side and the receiving side using a comparator.