JPH01103332A - Optical transmission equipment - Google Patents

Abstract

PURPOSE:To operate a line of the normal device side while preventing any danger to be inflected on a human body by decreasing a laser output level in the event of disconnection of optical fiber, and sending optical input interruption information as sub information together with a main signal. CONSTITUTION:If a fault of a broken optical fiber occurs at a point C of a transmission line 21 from a station A to a station B, an optoelectric conversion section 1' of the station B generates an optical input interruption alarm signal 13'. This signal together with the sub information signal 15' is multiplexed and sent to the station A while being superimposed on the main signal by a CMI coding section 5'. Moreover, the optical output level from the station B is decreased by using an optical output control signal 14'. Then the station A detects an alarm signal of the station B at a sub information demultiplex section 3 and uses an optical output control signal 14 to decrease the optical level of the station A. Furthermore, if both transmission lines are broken, the optical output level is decreased by using an optical input interruption alarm signal of its own station. Thus, danger to human body is prevented and the circuit of the sound system is operated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is applied to an optical transmission system using a radar diode as a light source. In particular, it relates to means for controlling laser diode light output.

〔overview〕

The present invention provides a means for protecting one of a pair of optical transmission lines when a disconnection accident occurs, by reducing the light intensity of the optical signal to the optical transmission line in the event of an accident and sending it to a healthy optical transmission line, thereby transmitting sub-information. It is designed to be able to execute.

[Conventional technology]

When using a laser diode as a light source, a method has been implemented in which the optical output is turned off to prevent the laser diode, which has a large optical output power, from directly entering the mouth due to an obstruction or the like. As shown in FIG. 3, if the fiber is cut at the zero point, there is a risk that the laser beam will directly enter the mouth at the zero point. In the conventional system, a fiber cut at point 0 generates an optical input cutoff alarm at point d of station B, and this alarm forcibly cuts off the optical output at point e of the local station. Next, at point f of the A station, an optical input interruption due to an optical output interruption of the B station is detected, and the optical output of the own station is turned off. In this way, the light output at point g is cut off, and the danger of laser light accidentally entering the eye at point 0 can be prevented.

FIG. 2 is a block diagram of a conventional end station device when a CMI code is used as a transmission line code. The optical output is cut off by the optical input cutoff alarm signal 13. Further, since the sub information is superimposed on the main signal using violation of the CMI coding rule, a sub information multiplexing section 4 and a sub information separating section 3 are provided.

[Problem that the invention seeks to solve]

In this way, in the conventional example, even if a failure such as disconnection occurs on only one transmission line between stations A and B, the optical output of the transmission line in the opposite direction is also cut off, so that the transmission on the normal side is interrupted. The disadvantage was that roads could no longer be used.

The present invention eliminates these drawbacks.In the case of fiber cutting, the optical output level is lowered to protect the eyes without cutting off the laser output, and optical input cutoff information is transmitted as sub information along with the main signal. However, the present invention aims to provide an optical transmission device that can keep the line on the normal side operational.

[Means for solving problems]

The present invention provides a means for multiplexing sub-information, a superimposing means for superimposing the sub-information multiplexed by the multiplexing means on a main signal, and a radar diode for converting an electrical signal output from the superimposing means into an optical signal. an optical transmission device comprising: a first circuit means for supplying the optical input disconnection information of the own device to the multiplexing means as one of the sub information; a second circuit means for providing input cutoff information to the light output control means of the laser diode, and the light output control means includes means for reducing the light output of the laser diode based on the light input cutoff information. Features.

[Effect]

When one transmission line is disconnected, the optical output level sent from the own station is lowered based on the optical input disconnection alarm signal received from the opposite station. Furthermore, when both transmission lines are disconnected, the level of optical output supplied from the local station to the disconnection point is similarly controlled to a non-hazardous and economically low level based on the optical input disconnection alarm signal of the local station.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings. 1st
The figure is a block configuration diagram showing the configuration of this embodiment.

As shown in FIG. 1, this embodiment includes a sub-information multiplexing section 4 in which a sub-information signal 15 and an optical input disconnection alarm signal 13 of its own station are manually transmitted, a data signal 17, a clock signal 18 and a sub-information multiplexing section 4. The coding rule violation signal 16 outputted from the section 4 is transmitted to the CMI encoding section 5 which is manually generated, and the C which is output from the CMf encoding section 5.
The MI transmission signal 19 is manually input to the electric-to-optical converter 6, the optical-to-electrical converter 1 connected to the optical transmission line 21', and the CMI reception signal 7 output from the optical-to-electrical converter 1 is manually input to the data. A CMI decoding section 2 outputs a signal 8, a clock signal 9, and a coding rule violation signal 10, and the coding rule violation signal 10 outputted from this CMI decoding section 2 is manually input to generate a sub information signal 11 and an optical input disconnection alarm of the other station. The sub-information separation unit 3 outputs the signal 12, and the optical input disconnection alarm signal 12 of the other station from the sub-information separation unit 3 and the optical input disconnection alarm signal 13 of the own station from the optical-electrical converter 1 are manually generated. , and an OR circuit 22 that provides the calculation result to the electro-optical converter 6.

Here, the features of the present invention are that the optical input disconnection alarm signal 13 is sent to the other station as a sub information signal, and that the optical input disconnection alarm signal 13 of the own station and the optical input disconnection alarm signal of the opposite station are transmitted. 12 is used as the optical output control signal 14 of the electrical-to-optical converter 6, which is a laser diode.

Now, when an optical fiber disconnection failure occurs at the 0 point of the transmission line 21 going from the A station to the B station, the optical-to-electrical converter 1' of the B station issues an optical input disconnection alarm signal 13'. This signal is multiplexed with other sub-information signals 15', superimposed on the main signal by the CMI encoder 5', and sent to the incoming station, where it is output as an optical output control signal 14' of the electro-optical converter 6, which is a laser diode. , and lowers the optical output level sent from station B below the normal level. Next, in the A station, the sub-information separation unit 3 detects the optical input disconnection alarm signal 12 of the B station, which becomes the optical output control signal 14 of the electric-to-optical converter 6, which is a laser diode, and is sent out from the A station. Lower the optical output level to cut point C.
reduce the light output level at the device to a level that does not pose a danger to the human body.

Additionally, if an optical fiber disconnection failure occurs on the transmission line on the opposite side at the same time, it will not be possible to send optical input disconnection information to the other station, but each station will detect the optical input disconnection and output its own optical output. By reducing the level, the optical power level at the point of cut remains at a non-hazardous low level, similar to if the optical fiber were cut on only one side.

〔Effect of the invention〕

As explained above, the present invention reduces the optical output level to a level that does not pose a danger to the human body without cutting off the optical fiber in the event of an optical fiber disconnection failure, thereby reducing power consumption to an economical level. This has the effect of allowing the side line to be used without interruption.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram showing the configuration of an embodiment of the present invention. FIG. 2 is a block configuration diagram showing the configuration of a conventional example. FIG. 3 is an explanatory diagram of the operation of the conventional example. 1.1'...Optical-electric conversion unit, 2.2'...CMI
Decoding unit, 3.3'...Sub information separation unit, 4.4'...
Sub information multiplexing section, 5.5'...CMI encoding section, 6.
6'...Electro-optical converter, 7.7'...CMI reception signal, 8.8', 17.17'...Data signal, 9.
9', 18.18'...Clock signal, 1O110'
, 16.16'... Sign rule violation signal, 11.11'
, 15.15'...Sub information signal, 12.12'...
・Optical input disconnection alarm signal (other station), 13.13'... Optical input disconnection alarm signal (own station), 14.14'... Optical output control signal, 19.19'... CMI transmission signal , 20.2
0'... Optical terminal station, 21. 21'... Optical transmission line, 22
．． 22'...OR circuit.

Claims (1)

[Claims] (1) A means for multiplexing sub-information, a superimposing means for superimposing the sub-information multiplexed by the multiplexing means on the main signal, and a laser diode for converting the electrical signal output from the superimposing means into an optical signal. In the optical transmission device, the first circuit means provides the optical input disconnection information of the own device as one of the sub-information to the multiplexing means, and the optical input disconnection information coming from the opposing device and/or the optical input disconnection information of the own device. a second circuit means for supplying information to the light output control means of the laser diode, and the light output control means includes means for reducing the light output of the laser diode based on the light input cutoff information. optical transmission equipment.