JPH0783333B2 - Signal transmission method - Google Patents

Description

The present invention relates to a signal transmission system, and more particularly to a signal transmission system for block-multiplexing and transmitting a plurality of data signals.

[Prior Art] FIG. 2 shows a signal transmission device and a signal reception device used in a conventional signal transmission system.

The signal transmission device 21 includes first to Nth input terminals 221 to 22N.
A first to Nth signal processing circuit (not shown), a multiplexing circuit 23, a first to Nth signal processing circuit and a multiplexing circuit
First to Nth data signal lines 241, 242, ...
It has 24N and a conversion circuit 25. Signal receiving device 26
Is a conversion circuit 27, a separation circuit 28, first to Nth signal processing circuits (not shown), and first to Nth output terminals 291.
Has ~ 29N.

Next, operations of the signal transmitting device 21 and the signal receiving device 26 will be described.

The first to Nth data signals input to the first to Nth input terminals 221 to 22N are signal-processed by the first to Nth signal processing circuits, respectively. twenty four
It is output to the multiplexing circuit 23 of 1 to 24N. The multiplexing circuit 23 block-multiplexes the input first to Nth data signals and outputs a block-multiplexed signal. The block multiplexed signal is converted into a transmission signal by the conversion circuit 25, and the transmission line 30
Sent to.

In the signal receiving circuit 26, the transmission path signal transmitted through the transmission path 30 is first converted into the block multiplexed signal by the conversion circuit 27. The block multiplexed signal is input to the demultiplexing circuit 28, and the first
Through Nth separation signal. The first to N-th separation signals are input to the signal processing circuit, respectively, returned to the original first to N-th data signals, and the first to N-th output terminals 291.
Each is supplied to ~ 29N.

[Problems to be Solved by the Invention] However, in the conventional signal transmission method, one of the plurality of data signals input to the signal transmission device is not input to the multiplexing circuit in the transmission device for some reason. When a state (state in which the code cannot be specified) occurs, after separating the block multiplexed signal in the signal receiving device,
When trying to perform signal processing, there is a problem that the code cannot be specified and the synchronization is lost.

The present invention provides a signal transmission method in which out-of-synchronization does not occur on the signal receiving device side even when any one of a plurality of data signals input to the signal transmitting device is not input to the multiplexing circuit. The purpose is to do.

[Means for Solving the Problem] According to the present invention, in a signal transmission system in which a plurality of data signals are input to a multiplexing means and block-multiplexed for transmission,
When any one of the plurality of data signals is not input to the multiplexing means, a predetermined signal is input to the multiplexing means instead of the non-input data signal, and block multiplexing is performed for transmission. A signal transmission system characterized by the above is obtained.

Further, in a signal transmitting apparatus for inputting the first to Nth data signals supplied via the first to Nth data signal lines to the multiplexing means, performing block multiplexing by the multiplexing means, and sending out to the transmission path. Monitoring the presence or absence of the first to Nth data signals on the first to Nth data signal lines,
To the 1st to Nth signal disconnection detection circuits that output the 1st to Nth signal disconnection detection signals when there is no said 1st to Nth data signal on said to Nth data lines; In response to N signal loss detection signals, first to N-th specific signal generations for supplying the first to N-th specific signals to the multiplexing means in place of the lost first to N-th data signals And a circuit.

Further, the first to N-th data signals including the first to N-th specific signals are block-multiplexed as a reception signal, and the reception signal is separated to receive the first to N-th data signals. In a signal receiving device having a separation means for outputting first to Nth separated signals corresponding to data signals, the first to Nth separated signals are respectively received to detect the first to Nth specific signals. The first to Nth detection signals are output when the first to Nth specific signals are detected,
To Nth specific signal detection circuit and first to Nth notification means for notifying that the first to Nth specific signals have been received in response to the first to Nth detection signals. A signal receiving device characterized by the above is obtained.

[Embodiment] Next, an embodiment of the present invention will be described with reference to the drawings.
Here, the same components as those of the conventional one are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 shows a block diagram of a signal transmitter and a signal receiver used in a signal transmission system according to an embodiment of the present invention.

The first to Nth data signal lines 24 of the signal transmitting device 21 of this embodiment are respectively connected to the first to Nth specific signal input circuits 111.
˜11N and the first to Nth input disconnection detection circuits 121 to 12N. Then, the outputs of the first to Nth specific signal input circuits 111 to 11N are input to the multiplexing circuit 23, and the outputs of the first to Nth input disconnection detection circuits 121 to 12N are respectively the first.
To Nth specific signal input circuits 111 to 11N.

In addition, the first output from the separation circuit 28 of the signal receiving device 26
The first to Nth separation signals are input to the first to Nth specific signal detection circuits 131 to 13N, and the outputs of the first to Nth specific signal detection circuits 131 to 13N are the first to Nth alarms, respectively. It is supplied to 141-14N.

The operation of this device will be described below.

When the signal transmission device 21 is operating normally, the first to Nth data signals 241 to 24N are input to the first to Nth specific signal input circuits 111 to 11N, respectively.
The data signal of is output to the multiplexing circuit 23 as it is.

Here, it is assumed that some abnormality has occurred in the signal transmission device 21 and any data signal (for example, the second data signal) cannot be supplied to the data line 242. Then, the signal loss detection circuit 122 detects that the second data signal on the second data line 24 has disappeared, and outputs the second detection signal to the second signal.
To the specific signal input circuit 112. The second specific signal input circuit 112 outputs the second specific signal to the multiplexing circuit 23 when the second detection signal is input. It is desirable to determine the code of the second specific signal so that the mark rate becomes 1/2.

The second specific signal input to the multiplexing circuit 23 is multiplexed with other data signals, converted into a transmission path signal, and transmitted to the signal receiving device 26.

In this way, even if any of the data signals is no longer input to the multiplexing circuit 23, a specific signal is input instead of the data signal that is no longer input, so that out-of-synchronization occurs on the signal receiving device 26 side. There is no such thing.

In the signal receiving device 26, as in the conventional case, after converting the transmission path signal into the block multiplexed signal, the block multiplexed signal is separated into the first to Nth separated signals by the separation circuit 28. The first to Nth separated signals are processed by the first to Nth signal processing circuits, respectively, and are supplied to the first to Nth output terminals 291 to 29N.

In addition, the first to Nth separated signals are respectively the first to Nth
It is also output to the specific signal detection circuits 131 to 13N.

The first to Nth specific signal detection circuits 131 to 13N receive the first to Nth separation signals from the signal separation circuit 28 and detect the first to Nth specific signals. In the present embodiment, since the second specific signal is input to the multiplexing circuit 23 instead of the second data signal, the second specific signal detection circuit 132 detects the second specific signal, The detection signal of 1 is output to the second notification device 142. When the second detection signal is input, the second annunciator 142 informs that the second data signal is lost in the signal transmission circuit 21 by sound and light.

[Effect] As described above, the present invention monitors the first to Nth data signals on the first to Nth data lines in the signal transmission device, and when there is no first to Nth data signal, First to Nth signal disconnection detection circuits that output first to Nth signal disconnection detection signals and multiplex first to Nth specific signals in response to the first to Nth signal disconnection detection signals When the data signal is not input to the multiplexing means, the specific signal is input to the multiplexing means instead of the data signal not input, and block multiplexing is performed. By performing the transmission in this manner, it is possible to prevent the occurrence of loss of synchronization on the signal receiving device side.

In addition, the signal receiving device detects the specific signal from the first to N-th signals.
By providing the specific signal detection circuit and the first to Nth alarms, it is possible to know that the specific signal is received, that is, that the data signal is not correctly transmitted, and the cause is the signal. It can also be known that it is on the transmitter side.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part of an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional signal transmitting apparatus and signal receiving apparatus. 21 …… Signal transmission device, 221-222N …… Input terminal, 23 …… Multiplexing circuit, 241-224N …… Data signal line, 25 …… Conversion circuit, 26
...... Signal receiver, 27 …… Conversion circuit, 28 …… Separation circuit, 291
〜29N …… Output terminal, 30 …… Transmission line, 111〜11N …… Specific signal input circuit, 121〜12N …… Signal disconnection detection circuit, 131〜13N ……
Specific signal detection circuit, 141 ~ 14N ... Alarm.

Claims (3)

[Claims] 1. In a signal transmission system in which a plurality of data signals are input to a multiplexing means and block-multiplexed and transmitted, when any one of the plurality of data signals is not input to the multiplexing means, it is input. A signal transmission system characterized in that a predetermined signal is input to the multiplexing means instead of a non-existing data signal, and is block-multiplexed for transmission. 2. A signal for inputting first to N-th data signals supplied through first to N-th data signal lines to a multiplexing means, block-multiplexing by the multiplexing means, and sending out to a transmission line. In the transmitter, the presence or absence of the first to Nth data signals on the first to Nth data signal lines is monitored, and the first to Nth data signals are detected on the first to Nth data lines. First to Nth signal loss detection circuits that output first to Nth signal loss detection signals when there is no signal, and the lost first signal in response to the first to Nth signal loss detection signals
A signal transmitting apparatus comprising: first to Nth specific signal generating circuits for supplying first to Nth specific signals instead of the Nth to Nth data signals to the multiplexing means. 3. A block-multiplexed signal obtained by block-multiplexing first to N-th data signals including first to N-th specific signals is received as a received signal, and the received signal is separated to obtain the first to N-th signals. In a signal receiving device having a separating means for outputting first to Nth separated signals corresponding to Nth data signals, the first to Nth specific signals are received by receiving the first to Nth separated signals, respectively. And a first to Nth specific signal detection circuit for outputting the first to Nth detection signals when the first to Nth specific signals are detected, and the first to Nth detection signals. A signal receiving device, comprising: a first to an Nth notifying means for notifying that the first to Nth specific signals have been received in response.