JPH0244933A - Fault detection system for multiplexer - Google Patents

Abstract

PURPOSE:To allow the title system to cope with a fault at the input side of a multiplexer quickly by providing a detection means of a frame synchronizing signal at every channel of each low-order group signal so as to detect a fault at every channel. CONSTITUTION:A frame synchronizing signal detection circuit is provided in a reception section 22 provided at every channel of a low-order group signal in a multiplexer 21 in a station A, and an output of each reception section 22 is multiplexed to a high-order group signal by a multiplex section 23 and sent to a station B via a transmission line 4. The low-order group signal from a communication equipment 1 includes a frame synchronizing signal and a bipolar signal form, the reception section 22 converts the signal into a unipolar signal form and the detection of whether or not the frame synchronizing signal is normal is implemented at all times and if the signal has an error, the alarm of the occurrence of a fault from the reception section 22 to the communication equipment 1 and the opposite communication equipment 11 is sent. Thus, the recovery processing of the faulty state is implemented quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for detecting failures for each channel of each low-order group signal in a multiplexing device.

[Conventional technology]

FIG. 2 shows a block diagram of a conventional example. When performing multiplex transmission between stations A and B facing each other, communication devices 1 and 11 with low transmission speeds are combined with other communication devices not shown in the diagram. Primary multiplexer 2. as the channel of the next group signal.
12, multiplexed into a high transmission rate secondary group signal here = 1, and further accommodated in secondary multiplexers 3 and 13 along with other equivalent primary multiplexers omitted in the figure. However, after multiplexing into a higher order group signal with a higher transmission rate, the higher order group signal is transmitted and received via the transmission line 4.

Further, the received signal is transmitted to the secondary multiplexers 3 and 13.
After being separated into the next group signals, and further separated into the first group signals by the first multiplexers 2 and 12, each communication device 1 and 11
sent to.

Here, for example, due to an abnormality in the communication device 1 or a mix-up in the transmission path between the communication device 1 and the primary multiplexer 2, the frame synchronization signal may be incorrectly received on the input channel side of the primary multiplexer 20. If this occurs, the state of the high-order group signal becomes a failure state, and the received signal becomes out of synchronization in the opposing communication device 11.
1, and sends a game warning to the communication device 1 via each multiplexing device 12, 13 and 3.2 to notify all occurrences of the failure.

[Problem to be solved by the invention]

However, in the conventional method, all fault detection and alarm transmission is performed between opposing communication devices, so it takes time for mutual recognition of the fault, and recovery measures from the fault state are not quick. This has resulted in the disadvantage that communication is not possible9 and the communication status is delayed.

[Means to solve the problem]

In order to solve all of the above-mentioned problems, the present invention is constructed by further means.

That is, in the above-mentioned multiplexing apparatus, a frame synchronization signal detection means is provided for each channel of each low-order group signal, and this detection means performs failure detection for each channel.

[Effect]

Therefore, a failure at the input end of the multiplexer is immediately detected, and recovery from the failure can be carried out quickly.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to the block diagram of FIG. 1 showing an embodiment.

The figure shows a case where station A performs multiplex transmission and station B performs multiplex reception, and low-order group signals from communication device 1 are transmitted from other communication devices (not shown in the figure). The signal is stored in the multiplexing device 21 together with the signal, and in the same device 21, the receiving section 22 provided for each channel of the low-order group signal includes all frame synchronization signal detection circuits, and each receiving section 22 The output is multiplexed into a higher-order group signal in the multiplexer 23 and then transmitted to the station B via the transmission line 4.

Note that the low-order group signal from the communication device 1 is in a bipolar signal format and includes a frame synchronization signal, and is converted into a unipolar signal format in the receiving section 22, and it is constantly detected whether or not the frame synchronization signal is normal. done, if
If an abnormality occurs in the signal, the receiving section 22 sends a warning to the communication device 1 and the opposing communication device 12 that a failure has occurred.

At station B, the high-order group signals are separated into low-order group signals by the separation section 32 of the multiplexing device 31, and then sent to the communication device 11 and other communication devices not shown in the figure via the transmission section 33. Since station B also has the configuration required for transmission equivalent to that of station A, and station A has the configuration required for reception equivalent to station B, the communication devices 1 and 11 Two-way communication between and communication device 1
1 side failure detection is performed.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the detection means for the frame synchronization signal is used for each channel of each low-order group signal, thereby detecting a fault for each channel, thereby achieving multiplexing. Failures on the device input side are immediately detected, countermeasures can be taken quickly, and communication failure time is shortened, resulting in significant effects in multiplexing devices for various uses.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional example. 1.11. Communication device, 21. 31.. Multiplexing device, 22.. Receiving section, 23.. Multiplexing section.

Claims (1)

[Claims] In an apparatus for multiplexing a plurality of low-order group signals into a high-order group signal, a frame synchronization signal detection means is provided for each channel of each of the low-order group signals, and the detection means performs failure detection for each channel. Features a fault detection method for multiplexing equipment.