JPH03148928A - Optical repeater - Google Patents

Abstract

PURPOSE:To prevent the errorneous connection of a switch owing to noise outputted from an identification circuit when a line is disconnected by transferring a control signal with the other optical repeater which is oppositely arranged and interrupting an input path from a self line-side to a supervisory control circuit when a signal to be inputted from the self line-side to the supervisory control circuit comes to a disconnected state. CONSTITUTION:By using that the power of a signal outputted from a limiter amplifier 16 through a surface acoustic wave(SAW) filter 15 is reduced when the data signal 1 of the self line-side is disconnected, the reduction of power is judged in a detection circuit 14 and a gate circuit 13 is closed. Thus, noise outputted from the identification circuit 9 when the line is disconnected is prevented from being inputted to the supervisory control circuit 4. Consequently, a control signal 2 from a confronting line can be received even if the self line is disconnected.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an optical repeater having a supervisory control circuit.

[Conventional technology]

FIG. 3 is a block diagram for explaining usage examples of the conventional optical repeater and the present invention. The figure shows a pair of optical repeaters 1
An example of use in which a bidirectional transmission path is configured with 0 and 11 is shown.
When the optical repeater 10 (or 11) has a control signal included in the received data signal, it monitors and controls itself according to the control signal and transmits the control signal 2 (or 3) to the optical repeater 11 (or 10) for monitoring and control.

A conventional optical repeater has a circuit configuration shown in FIG. The data signal 1 received by the optical repeater 10 is input to the identification circuit 9, where it is determined whether the binary signal level is 1'' or 0'', and is output as a reproduced signal. This playback signal is
Since modulation is added by mark rate modulation and parity violation, the bandpass filter (BPF) 12
By passing it through, it is possible to extract the average DC potential variation and separate the control signal superimposed on the data signal 1 of the own line. The extracted control signal 3 is also transferred to the repeater 11 on the opposite side, but is input to the detection circuit 5-1 in its own monitoring and control circuit 4 to detect the presence or absence of the control signal. In this case, the connection of the analog switch 6 is controlled so that the control signal 3 is guided to the command receiver side.

Further, when the control signal 2 of the opposite line is transferred from the repeater 11 to the monitoring control circuit 4 and the control signal 3 of the own line does not exist, the control signal 2 is transferred to the signal detection circuit 5-2.
The presence or absence of the control signal is detected, and if there is a control signal, the analog switch 6 is connected to the control signal 2.
is directed to the command receiver side.

The control signal 2 guided through the analog switch 6 or the command register buff is demodulated to the original baseband format signal, further waveform-shaped, and then input to the decoder 8 for various monitoring purposes. Instruct actions.

[Problems to be Solved by the Invention] In the above-described conventional optical repeater, the analog switch 6 in the supervisory control circuit 4 is configured to switch between when a control signal from the own line arrives and when a control signal from the opposite line arrives. The switching operation is performed to pass each control signal, but if the line on the own line side is disconnected, noise is output from the identification circuit 9, and this noise is detected by the detection circuit 5-. 1 is mistakenly recognized as a control signal, and the analog switch 6 is operated to the side where the control signal of the own line is bused, and the i
There is a drawback that when the lJrll signal arrives, it cannot be received.

[Means to solve the problem]

The optical repeater according to the first aspect of the present invention includes a monitoring control circuit that sends and receives control signals to and from another optical repeater placed oppositely to each other;
The apparatus further includes a switch means for cutting off an input path from the own line side to the supervisory control circuit when a signal to be input from the own line side to the supervisory control circuit is cut off.

The optical repeater of the second invention has a monitoring control circuit that sends and receives control signals to and from another optical repeater disposed opposite to each other, and a signal to be input from the own line side to the monitoring control circuit is disconnected. switch means for cutting off transfer of the control signal from the supervisory control circuit to the other optical repeater side when the optical repeater is in use.

〔Example〕

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

FIG. 1 is a block diagram showing an embodiment of the first aspect of the present invention. In this embodiment, when the data signal 1 on the own line side is disconnected, the power of the signal passed through the surface acoustic wave (SAW) filter 15 and output from the limiter amplifier 16 is reduced, which is used for detection. By determining this power reduction in the circuit 14 and closing the gate circuit 3, the noise output from the identification circuit 9 when the line is disconnected is prevented from being input to the supervisory control circuit 4.

As a result, even if the own line is disconnected, the control signal 2 from the opposite line can be received.

FIG. 2 is a block diagram showing an embodiment of the second invention of the present invention. In this embodiment, when the data signal 1 on the own line side is disconnected, the surface acoustic wave (S A W ) filter 15
Using the fact that the power of the signal output from the limiter amplifier 16 decreases, the detection circuit 14 determines the decrease in power and changes the threshold voltage 20 sent from the control circuit 21 to the comparator 18. .

First, the control signal 3 on the own line side output from the BPF 12
is also transferred to the opposite repeater (11) via the supervisory control circuit 40, but the gate circuit 19 is controlled to be cut off by the change in threshold voltage that occurs when the own line is disconnected. As a result, when the data signal 1 is disconnected, the control signal is no longer transmitted to the opposite repeater side.

On the other hand, the control signal 3 is transmitted to the rectifier circuit 1 in the supervisory control circuit 40.
7 and is rectified. The rectified signal is sent to comparator 18
However, if the data signal l is disconnected,
Depending on the change in the threshold voltage mentioned above, the output signal of the comparator 18 controls the analog switch 6 to be disconnected from the command receiver. As a result, even if the own line is disconnected, the analog switch 16 operates normally and can receive the control signal 2 from the opposite line.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to prevent incorrect switch connections caused by noise output from the identification circuit when a line is disconnected, and to receive control signals from the opposite line.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 represent the first and second embodiments of the present invention, respectively.
3 is a block diagram showing an example of the invention, FIG. 3 is a block diagram of a conventional optical repeater, and FIG. 4 is a block diagram showing an example of use of the conventional optical repeater and the present invention.

1-・Data signal, 2.3... Control signal, 4.40-
・Monitoring control circuit, 5-1.5-2...detection circuit, 6
- Analog switch, 7 - Command receiver, 8... Decoder, 9... Identification circuit, 10.1
1 - Optical repeater, 12 - Band pass filter (BPF)
, 13.19...-gate circuit, 14...-detection circuit,
15...SAW (surface acoustic wave) filter, 16...
Limiter amplifier, 17... Rectifier circuit, 18... Comparator, 20... Threshold voltage, 21... Control circuit.

Claims (1)

[Claims] 1. A monitoring control circuit that sends and receives control signals to and from another optical repeater disposed oppositely, and a signal to be input from the own line side to the monitoring control circuit are disconnected. 1. An optical repeater comprising switch means for occasionally cutting off an input path from the own line side to the monitoring control circuit. 2. A supervisory control circuit that sends and receives control signals to and from another optical repeater arranged oppositely, and a supervisory control circuit that sends and receives control signals from the supervisory control circuit when the signal to be input from the own line side to the supervisory control circuit is disconnected. An optical repeater comprising switch means for blocking transfer of the control signal to another optical repeater.