JPS6384331A - Remote loop-back system for digital multiplex converting device - Google Patents

Abstract

PURPOSE:To simplify a multiplexing circuit set at the transmitting side and also a separating circuit set at the receiving side, by adding a specific pattern at the transmitting side and detecting the specific pattern at the receiving side to carry out a remote loop-back operation toward the transmitting side. CONSTITUTION:A transmitting side device A gives a remote loop-back instruction to a specific pattern generating circuit 5 from a channel board 1, for example, out of those boards 1-4. Then the circuit 5 produces a specific pattern in 4 bits, for example, in response to a 1st channel and sends it to an inserting circuit 6. The circuit 6 puts the specific pattern on a single service bit contained in a synchronous frame and sends the pattern in plural frames. A receiving side device B detects the specific pattern from the service bits of plural frames for multiplexing signals through a detecting circuit 7. Thus the 1st channel is confirmed. A remote loop-back control selector circuit 8 sends a remote loop-back signal to a channel board 11 based on the detection output of the circuit 7 and carriers out a remote loop-back operation to the transmitting side.

Description

DETAILED DESCRIPTION OF THE INVENTION Eleventh Industrial Field of the Invention The present invention relates to a transmission system using a digital multiplex converter, and in particular to a remote loopback system in which a transmitted signal is sent back as it is in order to discover line faults, etc. It is related to the method.

BACKGROUND OF THE INVENTION Conventionally, an example of a remote loopback method for this type of digital multiplex converter is a method in which a remote loopback command is placed on a vacant stuff bit of pulse stuff ink synchronization, which is widely used. was being carried out. Fig. 2 shows a conventional example of a 4-channel multiplexing device, in which a transmitting device A is connected to four channel boards 1 to 4, and is connected to each of these. Four circuits 25 for inserting remote loopback commands into bits, a circuit 26 for combining these outputs, a remote loopback signal detection circuit 27 connected to the receiving side device B, and a remote loop signal detection circuit 27 connected to this detection circuit 27. It consisted of four remote loopback command signal control circuits 28 that recognize back commands and apply them to the corresponding channel boards, and four channel boards 11 to 14 on the receiving side connected to each of these circuits.

Therefore, there is a drawback that four remote loopback command insertion circuits 25 and four remote loopback command signal control circuits 28 are required.

Problems to be Solved by the Invention The purpose of the present invention is to solve the above-mentioned drawbacks, that is, to utilize the stuff bits of each channel. An object of the present invention is to provide a remote loopback method for a digital multiplex converter that solves the problem that the same number of loopback command insertion circuits and remote loopback command signal control circuits on the receiving side are required as the number of channels. .

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a plurality of channel boards and a specific pattern connected to the plurality of channel boards that corresponds to the remote loopback signal of each channel. A transmitting side device includes a specific pattern generation circuit that generates a specific pattern, a specific pattern insertion circuit that inserts the specific pattern into stuff bits at a position specified for each channel in a synchronization frame, a receiving side device having a specific pattern detection circuit that detects a specific pattern from among the channels, a remote loopback control selector circuit that sends a remote loopback signal to a channel board corresponding to the specific pattern, and a plurality of channel boards. The following configuration is adopted.

Operation Since the present invention is configured as described above, in the transmitting side device, the specific pattern generation circuit changes the remote loopback command of the channel into a specific pattern for that channel, and the specific pattern insertion circuit inserts this specific pattern into the frame. The receiving device detects multiple frames of the specific pattern inserted into the stuff bits from the received multiplexed signal using a specific pattern detection circuit, and detects the corresponding channel. A remote loopback control selector circuit sends a remote loopback signal to that channel to perform all remote loopback operations.

Example Next, embodiments of the present invention will be described with reference to the drawings.

Referring to FIG. 1, which shows a block diagram of an embodiment of the present invention, the 4-channel digital multiplex converter of the present invention includes:
A transmitting side device A having four channel boards 1 to 4, a specific pattern generation circuit 5 connected to all of these, and a specific pattern insertion circuit 6 connected to this specific pattern generation circuit 5, and a specific pattern detection circuit. 7, a remote loopback control selector circuit 8, and a receiving side device B having four channel boards 11 to 14 on the receiving side.

Next, the operation of this embodiment will be explained using FIG.

In the sending device A, a remote loopback command is sent to the specific pattern generation circuit 5 from any one of the channel boards 1 to 4, for example, the channel board 1 of the first channel. The specific pattern generation circuit generates a specific pattern corresponding to the first channel using, for example, 4 bits and sends it to the specific pattern insertion circuit 6.

The specific pattern insertion circuit 6 places the specific pattern on one service bit in the synchronization frame and sends the synchronization frame divided into a plurality of frames. In the receiving device B, the specific pattern detection circuit 7 detects a specific pattern from the service bits of multiple frames of the received multiplexed signal, and confirms that the specific pattern is the first channel. In response to this detection output, the remote loopback control selector circuit 8 sends a remote loopback signal to the first channel board 11, and remote loopback to the transmitting side is executed. The same is true if the remote loopback instruction is not for the first channel but for other channels.

Therefore, only one specific pattern generation circuit 5 and one remote loop control selector circuit 8 are required regardless of the number of channels, which has the advantage of simplifying the circuit and reducing cost.

In this embodiment, the number of channels' is set to 4, but the number can be applied to any case.

Effects of the Invention As described above, according to the present invention, the transmitting side device is provided with a specific pattern generation circuit and the specific pattern insertion circuit, and the receiving side device is provided with a specific pattern detection circuit and a remote loopback control selector circuit. By providing a remote loopback instruction, it is possible to place a remote loopback instruction in a stuff bit at a position specified for each channel in a synchronization frame,
The multiplexing circuit on the transmitting side and the separating circuit on the receiving side are simplified.
This has the effect of lowering the price.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a digital multiplex converter according to an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional example. 1 to 4...Sending side channel board, 5...
Specific pattern generation circuit, 6... Specific pattern insertion circuit, 7... Specific pattern detection circuit, 8...
...Remote loopback control selector circuit, 11
-14...°...Receiving side channel board, 10...
・Multiplexing circuit (circuit 5 and circuit 6), 20-part separation circuit (circuit 7 and circuit 8), bar series

Claims (1)

[Claims] Connected to multiple channel boards and each of these channel boards, the remote loopback command signal of each channel is inserted into the stuff bit at a position specified for each channel in the synchronization frame, and is multiplexed with the data signal as a multiplexed signal. a transmitting side device having a multiplexing circuit for transmitting the multiplexed signal; a separating circuit for receiving the multiplexed signal, detecting a remote loopback signal therein, separating it into corresponding channels together with the data signal, and transmitting the multiplexed signal; In a remote loopback method of a digital multiplex conversion device, the remote loopback method of a digital multiplex converter comprises a receiving device having a plurality of channel boards connected to a separation circuit, and the receiving device detects a remote loopback command signal from the transmitting device. , a specific pattern generating circuit that causes the multiplexing circuit of the transmitting side device to generate a specific pattern corresponding to a remote loopback signal of each channel; and a specific pattern insertion circuit that inserts this specific pattern into stuff bits in a synchronization frame. and a remote loopback control selector that sends a remote loopback signal to a channel board corresponding to the specific pattern; A remote loopback method of a digital multiplex converter, characterized in that a circuit is provided.