JPH02241238A - Remote loop back testing system - Google Patents

Abstract

PURPOSE:To execute simple line check without interrupting service by incorporating a pattern generation circuit and an error detection circuit, and transmitting/ receiving a test pattern by using an excess bit. CONSTITUTION:At the time of the remote loop test of an M12 asynchronous multiplexer, the error check of a line is executed by using the excess bit by transmitting the test pattern as data to be tested from the pattern generation circuit 4 in the asynchronous multiplexer 1 of a local side by inserting it into the excess bit, and afterwards, in the asynchronous multiplexer 6 of a remote side, receiving this test pattern by a receiving side circuit 7, and folding it to the local side by re-putting it on the excess bit by a transmission side circuit 8.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a maintenance method for an asynchronous digital multiplexer, and more particularly to a remote loopback test method that uses surplus bits in an asynchronous multiplexer to prevent service interruption. It is.

[Conventional technology]

Conventionally, when performing a remote loopback test to check line errors during maintenance of asynchronous multiplexing equipment, the path was disconnected from service in advance, and then the equipment was equipped with a pattern generation measuring device and an error detection measuring device. I connected it and ran a test.

FIG. 3 shows an example of this conventional method, and uses the M12 asynchronous multi-icing device as an example. That is, FIG. 3 shows the remote loopback test of one of the four channels of the asynchronous multiplexer 21, in which a pattern generator (PG) 29 is installed on the input side.
An error detection measuring device (ED) 30 is connected to each output side. Then, the test was conducted by remotely controlling the switching relays 27 and 28 of the asynchronous multiplexing device 24 on the remote side of D and switching them from the contact point a to the contact side, respectively. At this time, since the switching relays 27 and 28 have been switched to the contact side, the line service has been cut off. In FIG. 3, 22 is a transmitting circuit constituting the asynchronous multiplexer 21 on the local side, 23 is a receiving circuit thereof, and 2
Reference numeral 5 designates a receiving circuit constituting the asynchronous multiplexing device 24 on the remote side, and 26 designates a transmitting circuit thereof. Also, 3
1, 32 and 33 are the respective outside lines.

[Problem to be solved by the invention]

As described above, in the conventional method described above, there is a problem that service is inevitably interrupted during a remote loopback test, and it is necessary to prepare a pattern generation measuring device and an error detection measuring device.

[Means to solve the problem]

In order to solve these problems, the loopback test method of the present invention incorporates a pattern generation circuit and an error detection circuit on the local side of an asynchronous digital multiplexer, and the local side has a built-in pattern generation circuit and an error detection circuit. The pattern generation circuit inserts the test data into the surplus bits and sends it to the remote side, and the remote side replaces the test data with the surplus bits and returns it to the local side, and then sends it to the error detection circuit on the local side. By detecting the test data, the surplus bits are used to check the line.

[Effect]

Therefore, in the present invention, a pattern generation circuit and an error detection circuit are built-in as a remote loopback test method for checking line errors, and by using surplus bits to remove test data, service interruption is possible. It becomes possible to perform a simple line check without having to do anything.

〔Example〕

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

FIG. 1 is a conceptual diagram showing an example of the application of the remote loopback test method according to the present invention to an M12 asynchronous multiplexer. In the figure, 1 is a local side asynchronous multiplexing device to which the present invention is applied, and this device 1 includes a pattern generation circuit 4 and an error detection circuit in addition to a normal transmitting side circuit 2 and receiving side circuit 3. It has a built-in 5. Reference numeral 6 denotes an asynchronous multiplexing device on the opposing side J91J mote side to which the present invention is applied, and includes a receiving side circuit 7 and a transmitting side circuit 8.

That is, in this embodiment, during a remote loopback test of the M12 asynchronous multiplexer, a test pattern as data to be tested is inserted into surplus bits by the pattern generation circuit 4 in the asynchronous multiplexer 1 on the local side, and After transmitting the test pattern to the network, the receiving circuit T receives the test pattern in the asynchronous multiplexing device 6 on the to-net side, and the transmitting circuit 8 replaces it with surplus bits and loops it back to the local side. The surplus bits are used to check for line errors.

In addition, in FIG. 1, 9 indicates a loopback signal sent using surplus bits, and 10°11 and 12
indicates each outside line.

According to the test method of this embodiment, the asynchronous multiplexer 1
In this case, the test pattern generated by the built-in pattern generation circuit 4 is inserted one bit at a time into the surplus bits of the frame format of the data after multiplexing by the transmitting side circuit 2. In this case, the location of the surplus bit is the location of the stuff bit 13, as shown in FIG. 2 in this example. Incidentally, FIG. 2 shows the signal format of the generally well-known M12 asynchronous multiplexer, and has a transmission rate of 6°3.
12Mk'/a 4-channel signal data (01 to 0
4) and control bits (Ml, C1l, FO, C12
, C13.

Fl, .11, etc.) is schematically shown.

The test pattern inserted into the surplus bits by the receiving circuit T of the opposing asynchronous multiplexing device 6 is looped back by being placed on the surplus bits again in the transmitting circuit 8. Therefore, in the asynchronous multiplexing device 1 on the local side, the reception side circuit 3 receives a test pattern from the surplus bits, and the built-in error detection circuit 5 detects and compares it, and based on the comparison result, the service is interrupted. You can perform a simple line error check without having to do anything.

〔Effect of the invention〕

As explained above, the present invention incorporates a pattern generation circuit and an error detection circuit in an asynchronous multiplexing device.
During a remote loopback test, by using surplus bits to shorten the test pattern, you can easily perform a This has the effect of making it possible to check the line.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of the conventional method in which the method of the present invention is applied to an asynchronous multiplexing device. 1.---Asynchronous multiplexer (local side), 2.e.
・Sending side circuit, 3. Fist... Receiving side circuit, 4. Fist... Pattern generation circuit (PG), 5. Fist... Error detection circuit (E
D), 6... Asynchronous multiplexer (remote side), T
・・・Receiving side circuit, 8 fists... transmitting side circuit, 9...
・Loopback signal.

Claims (1)

[Claims] In an asynchronous digital multiplexing device, a pattern generation circuit and an error detection circuit are built in on the local side, and the local side inserts test data into surplus bits from the pattern generation circuit and transmits it to the remote side. On the side, the test data is transferred back to the local side with surplus bits again, and the error detection circuit on the local side detects the test data, thereby checking the line using the surplus bits. Remote loopback test method.