JPH0394529A - Optical output automatic interruption system - Google Patents

Abstract

PURPOSE:To surely and safely interrupt an optical signal by stopping automatically the transmission of an optical signal from a 2nd station to a 1st station when a fault signal inserted in an overhead signal in an optical digital signal is detected. CONSTITUTION:Input interruption detection circuits 4, 9 monitor an overhead signal of a predetermined channel in an optical digital signal and sends an input interrupt signal representing the interruption of an optical fiber transmission line 11 to an optical interrupt section 6 when a fault of the overhead signal is detected. An optical transmission section 7 receiving an input interrupt signal and an optical digital input signal inserts the input interrupt signal to an overhead signal of a different channel to form the optical digital signal and the signal is sent to an optical reception section 8 in a station A via an optical fiber transmission line 12. An input interrupt detection circuit 9 receiving the optical digital signal sends the input interrupt signal to the optical interrupt section 1. Thus, the optical interrupt section 1 interrupts the optical digital signal to be sent to a station B.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J The present invention is directed to an optical output device that automatically cuts off a high-power laser signal sent from a transmitting device during failure maintenance of an optical fiber transmission line using a high-power laser. This concerns the automatic shutoff system. [Conventional technology] Conventionally, optical communication devices that use light-emitting diodes or low-power lasers as light-emitting elements do not pose any particular safety problems, and therefore optical output can be automatically reduced in the event of a failure or maintenance of an optical fiber transmission line. There is no need for anything to block it. However, in recent years, the need for long-distance optical transmission has increased, and as the use of single-mode fibers has expanded, cases are increasing where strong optical signals with narrow beams are sent out from transmitters. , safety in the event of failure has become an issue. In order to ensure safety in the event of a failure of this optical fiber transmission line, optical signals have conventionally been cut off using a mechanical cut-off mechanism as shown in FIG.

FIG. 3(a) is an explanatory diagram when the optical fiber transmission line is not an obstacle, that is, when the cutoff mechanism is not operating. In the same figure, 30 and 31 are connectors,
32 is a shielding lid that shields the optical signal, and p is the optical signal. When the optical fiber transmission path becomes a failure, the connector 31 is removed by a maintenance person, and a blocking mechanism consisting of a shielding lid 32 blocks the transmission of the optical signal p, as shown in FIG. 3(b). As a result, the transmission of the optical signal p is cut off. [Problems to be Solved by the Invention] In the conventional optical output cutoff method described above, when a maintenance person accidentally operates the cutoff mechanism that cuts off the optical signal p during a failure or maintenance, it is easy for a high-output optical signal to be cut off. There was a problem in that it was sent outside and became extremely dangerous to handle.

[Means for Solving the Problems] In order to solve such problems, the optical output automatic cutoff system of the present invention has a first station that monitors an overhead signal in an optical digital signal arriving from a second station. When this abnormality is detected, the optical fiber transmission line from the second station to the first station is determined to be abnormal, and a fault signal indicating that this optical fiber transmission line is abnormal is transmitted in the optical digital signal. is inserted into the overhead signal of the first station and transmitted to the second station via an optical fiber transmission line from the first station to the second station. It is configured to receive a digital signal, detect the above-mentioned interference signal inserted into an overhead signal in this signal, and stop transmission of the optical digital signal to the first station.

[Operation] When receiving the optical digital signal transmitted from the first station and detecting the interference signal inserted into the overhead signal in the optical digital signal, the optical digital signal is transmitted to the first station. automatically stop. As a result, in the event of a failure in the optical fiber transmission line, the optical digital signal can be safely and reliably interrupted.

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

FIG. 1 is a block diagram showing an embodiment of a device to which the automatic light output cutoff method of the present invention is applied. In the figure, 1.6 is a light blocking unit that stops sending out optical signals, 2 and 7 are optical transmitting units that transmit optical signals, and 3.8 is an optical receiving unit that receives optical signals.
4.9 is an input disconnection detection circuit that detects an input disconnection of an optical signal; 5
．． 10 is a forced output command unit in which a maintenance person inserts, for example, a transmission power check signal into an overhead signal that is a maintenance signal and forcibly sends it to the game; 11.12 is an optical fiber transmission line; M1 to M4 are Monitoring point that monitors optical signals, F is the failure point of the optical fiber transmission line, DINI
, DIN. 2 is an input terminal, DoUTI and DOUT2 are output terminals, and A and B are stations. Next, the case where an optical digital signal is transmitted from station A to station B will be explained. In optical transmitter 2 in station A, input terminal D
It receives the optical digital signal via the INI and the optical cutoff section (2), and transmits this signal to the optical reception section 3 in the station B via the optical fiber transmission line 1l. The optical receiver 3 receives this optical digital signal and sends this signal to the output terminal DOUT2 via the input disconnection detection circuit 4.

The same applies when transmitting an optical digital signal from station B to station A. That is, in the optical transmitter 7 in station B, the input terminals DIN2. It receives the optical digital signal via the optical cutoff section 6 and transmits this signal to the optical reception section 8 in the station A via the optical fiber transmission line 12. The optical receiver 8 receives this optical digital signal and sends this signal to the output terminal DOUTI via the input disconnection detection circuit 9. Even when bidirectional communication of optical digital signals is performed in this way, the input disconnection detection circuit 4.9 always detects a predetermined channel of the optical digital signal, which will be described later, via the optical receivers 3 and 8. For example, if there is a failure point F on the optical fiber transmission line 11,
When the optical fiber transmission line 11 is disconnected, the above-mentioned overhead signal becomes abnormal, and the input disconnection detection circuit 4 in station B detects an abnormality in the overhead signal received via the optical receiver 3. Then, an input disconnection signal (failure signal) indicating that this optical fiber transmission line 1 is disconnected
is sent to the light blocking section 6. Then, the light shielding section 117r 6 receives this input cutoff signal and connects this signal to the input terminal DIN.
The optical digital human signal from 2 is sent to the optical transmitter 7. On the other hand, the optical transmitter 7 which has received this input disconnection signal and the optical digital input signal inserts this input disconnection signal into an overhead signal of a channel different from the above in the optical digital input signal to generate an optical digital signal. This signal is transmitted to the optical receiver 8 in station A via the optical fiber transmission line l2. The optical receiving section 8 receives the optical digital signal from the station B and sends this signal to the input disconnection detection circuit 9. In addition, the input disconnection detection circuit 9 that has received this optical digital signal sends this signal to the output terminal DOUT2, and extracts the input disconnection signal inserted into the overhead signal of the above-mentioned channel from this signal to shut off the light. When the optical cutoff section 1 receives this input cutoff signal, it cuts off the optical digital signal coming from the input terminal DINI and which should originally be sent to the station B.

As a result, the optical digital signal is not transmitted from the optical transmitter 2 to the station B via the optical fiber transmission line l1.

Next, FIG. 2(a) is an explanatory diagram illustrating the structure of the entire data stream of the optical signal transmitted from the optical transmitter 2.7. The total amount of data is 270x9=2430 bytes.The transmission speed of 1 byte of data is 6
4kbρS, so the overall data transmission rate is
2430 x 64kbps = 155.5Mbps. This 2430-byte optical data signal is repeatedly sent and received over the optical fiber transmission line at this ultra-high transmission speed. Moreover, 20.21 is an overhead part, and maintenance data by a maintenance person is set in this part as described above. Further, 22 is called a payload section, and user data is set in this section.

Further, FIG. 2(b) is an explanatory diagram illustrating the detailed configuration of the overhead section 20.21. D1 to DI in the diagram
2 indicates an overhead signal for each channel. For example, station B constantly monitors the overhead signal D1 of a predetermined channel, and if the optical fiber transmission line l1 is disconnected at failure point F as described above, an abnormality in this overhead signal DI is detected. To detect.
Then, an input disconnection signal indicating that the optical fiber transmission line 11 is disconnected is inserted into the overhead signal D2 of the optical digital signal transmitted to the station A via the optical fiber transmission line 12, for example. Send. As a result, station A receives this overhead signal D2, detects the input disconnection signal inserted into this signal, and stops transmitting the optical digital signal to station B based on the detected input disconnection signal. Let. [Effects of the Invention] As explained above, the optical output automatic cut-off system of the present invention receives an optical digital signal transmitted from a first station at a second station, and from now on, the overhead signal in the digital signal is The system is configured to automatically stop the transmission of optical digital signals from the second station to the first station when a fault signal inserted into the station is detected, allowing the optical signal to be cut off reliably and safely. effective.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the automatic optical output cut-off method of the present invention, Fig. 2 is an explanatory diagram illustrating the transmission of a fault signal in this automatic output cut-off method, and Fig. 3 is a diagram showing the conventional optical output cut-off method. FIG. 2 is an explanatory diagram illustrating a shutoff method. 1, 6... One light blocking part, 2
, 7.1... Optical transmitter, 3.8... Optical receiver, 4.
9.1. Input disconnection detection circuit.

Claims (1)

[Claims] A first device comprising an optical signal transmitting section and an optical signal receiving section.
In an optical signal transmission system that transmits and receives bidirectional optical digital signals between a station and a second station via an optical fiber transmission line, the optical digital signal arriving from the second station at the first station When this abnormality is detected by monitoring the overhead signal in the optical fiber transmission line from the second station to the first station, the optical fiber transmission line from the second station to the first station is determined to be abnormal, and a failure indicating that this optical fiber transmission line is abnormal is detected. A signal is inserted into an overhead signal of an optical digital signal to transmit the signal from the first station to the second station.
to a second station via an optical fiber transmission line to the station;
The second station receives the optical digital signal transmitted from the first station, detects the interference signal inserted into the overhead signal in this signal, and transmits the optical digital signal to the first station. An optical output automatic cutoff method characterized by automatically stopping transmission.