JPS63148729A - Optical repeater - Google Patents

Abstract

PURPOSE:To make a sending-out time of laser light constant, and to stabilize start of all systems by using a reset signal separated by each repeater as a trigger signal, and always generating a reset pulse only for a prescribed time. CONSTITUTION:An optical repeater station separates a reset signal 12 send out of a W station side, by an information separating part 8 and sends it out to a reset pulse generating part 10. The reset pulse generating part triggers an inputted reset signal, sends out the reset signal only for a prescribed time, makes an optical output inhibiting signal 11 ineffective, and also, superposes the reset signal on a CMI signal and sends it out to the next E station. In such a way, the sending-out time of an optical signal sent out of an electrooptical converting part 7 is mode constant, irrespective of the position of a station which has sent out the reset signal first.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a starting means for an optical transmission system that automatically turns off the optical output of a laser diode when an optical transmission line is disconnected.

(Summary) The present invention is an optical transmission method in which the optical input disconnection signal that immediately stops leakage of laser light in the event of a transmission line disconnection accident and starts the own system, relays a reset signal to temporarily disable it. By regenerating the pulse into a predetermined length pulse and transmitting it to the subsequent repeater, the system can be started stably regardless of the number of repeaters.

[Conventional technology]

When a laser diode is used as a light emitting device,
Since the output power of a laser diode is larger than that of an LED, it is dangerous if the laser light enters the eyes in the event of a failure such as a disconnection of the line. Therefore, in order to prevent this danger, a method has been devised that detects line disconnection and automatically shuts off the laser output.

An example is shown in FIG. In FIG. 2, for example, if the line is disconnected at point a, the output at point g on the W station side must be turned off, but the optical output cannot be turned off immediately. First, an optical input interruption is detected at point b on the E station side, and an optical output prohibition signal 11 is sent to the electrical/optical converter 7, thereby turning off the optical output at point d on the E station side. Subsequently, the optical input interruption is detected at the 0 point of the optical/electrical converter 4 on the W station side, and the optical output prohibition signal 11 is sent to the electric/optical converter 7, thereby cutting off the optical output at the g point on the W station side. state. In this way, leakage of laser light at the point of failure is stopped.

FIG. 3 shows a case in which there are two relay stations. In the figure, there are three loops that prohibit laser output.

Therefore, when starting up the entire system, in addition to turning on the power, the optical output prohibition signal 11 is
It is necessary to separate it from the light conversion section 7.

When using a CMI code as a transmission line code,
A reset signal that activates the entire system is sent as a sub information signal using a violation of the coding rule, and the optical output prohibition signal 1 of each station is transmitted.
1 can be disabled.

FIG. 4 is a detailed block diagram for explaining this reset operation. The reset signal 12 can be sent from any station, W station, E station, or relay station, and can start up the entire system connected to the line. - As an example, a case where the W station sends the reset signal 12 will be explained. After the power is turned on, feedback is applied to both loop 1 and loop 2, so the optical output prohibition signal 11 becomes the optical output control signal 13, and no optical output is transmitted from either station.

The reset signal 12 inputted from the terminal 3 of the W station invalidates the optical output prohibition signal 11 by the AND gate, and sends out light from the electrical-to-optical converter 7, and also passes through the sub-information superimposing unit 9 to the CMI code. The signal is superimposed on the optical signal and sent to the optical transmission line 14 as part of the optical signal. In the optical repeater 2, since the optical signal is received, the optical output prohibition signal 11 is canceled, light is outputted from the electrical-to-optical converter 7 on the E-W side, and the loop 1 enters the operating state.

On the other hand, the reset signal 12 is separated by the sub-information separation unit 8, invalidates the optical output prohibition signal 11 of the electrical-to-optical converter 7 on the W-E side, and transmits optical output, and is superimposed on the CMI signal again. and sent to station E. Since the E station received the optical signal, the optical output prohibition signal 11 is sent as in the case of optical repeater 2.
is released, light is output from the electrical/optical converter 7 on the E-W side, and the loop 2 also enters the operating state.

[Problem that the invention seeks to solve]

By the way, the reset signal is CM! Since it is superimposed on the signal, the pulse width of the separated reset signal is usually different from the pulse width at the time of input. Further, since the reset signal at startup causes light to be output even if the line is actually disconnected, it is preferable for the pulse sending time to be short from the viewpoint of safety.

In the case of Figure 3, there were only two relay stations, so changes in the pulse width of the reset signal were not a problem, but in a configuration with many relay stations, the pulse width of the reset signal at the farthest station It is assumed that the width may be significantly different from the width at the time of input. Therefore, if the pulse width changes to become progressively shorter, there is a possibility that the farthest system cannot be activated.

[Means for solving problems]

The present invention includes a laser diode that is inserted into an optical transmission line, and
and a first control means that turns off the output light of the laser diode based on the optical input cutoff signal, and further includes a first control means that temporarily disables the optical input cutoff signal based on the reset signal that arrives via the optical transmission line. In an optical repeater equipped with a second control means to transfer the reset signal to a subsequent optical repeater, the reset signal to be transferred is a pulse that continues for a predetermined period of time based on the arrived reset signal. It is characterized by comprising a signal reproducing means for reproducing the signal.

[Effect]

Instead of directly transmitting the reset signal separated by each repeater to the next station, the reset signal is used as a trigger signal to always generate a reset pulse for a fixed period of time, thereby making the laser beam transmission time constant. This makes the reset time constant throughout the system, regardless of the distance from the station that first sent the reset signal.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block configuration diagram showing the configuration of an embodiment of the present invention. 1 is an optical terminal station, 2 is an optical relay station, 3 is a reset signal input terminal, 4 is an optical/electrical converter, 5 is a CMI decoder, 6 is a CMI encoder, and 7 is an electric - Optical converter, reference numeral 8 is a sub-information separation unit, reference numeral 9 is a sub-information superimposition unit, reference numeral 10 is a reset pulse generator, reference numeral 11 is an optical output prohibition signal, reference numeral 12 is a reset signal, reference numeral 13 is an optical output control signal. , and 14 indicate optical transmission lines, respectively. A feature of the present invention is that the optical relay station 2 includes a reset pulse generator 10.
is at the point where is added.

The operation when the W station sends a reset signal will be explained. In the optical relay station 2, the reset signal 12 is sent to the sub information separation section 8.
and sends it to the reset pulse generator 10. The reset pulse generator 10 uses the inputted reset signal as a trigger to send out a reset signal for a certain period of time to invalidate the optical output prohibition signal 11, and also superimposes the reset signal on the CMI signal and sends it to the next station. . This results in
The sending time of the optical signal sent from the electrical-to-optical converter 7 by the reset signal is made constant regardless of the position of the station that first sent the reset signal.

〔Effect of the invention〕

As explained above, the present invention has the advantage that the entire system can be started stably from any station regardless of the number of optical relay stations.

[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 an explanatory diagram of the operation of cutting off laser output. FIG. 3 is an explanatory diagram of line activation operation. FIG. 4 is a block configuration diagram showing the configuration of a conventional example. DESCRIPTION OF SYMBOLS 1... Optical terminal station, 2... Optical relay station, 3... Reset signal input terminal, 4... Optical/electric conversion unit, 5... CM
I decoding section, 6...CM! Encoding section, 7... Electrical/optical converting section, 8... Sub information separating section, 9... Sub information superimposing section, 10... Reset pulse generating section, 11... Optical output prohibition signal, 12... Reset signal, 13... Optical output control signal, 14... Optical transmission line. Figure 2.

Claims (1)

[Claims] (1) The laser diode is inserted into an optical transmission line, and includes a first control means that turns off the output light of the laser diode based on an optical input cutoff signal, and further includes a In an optical repeater comprising a second control means for temporarily disabling the optical input cutoff signal based on a reset signal to be transmitted, and a transfer means for transmitting this reset signal to a subsequent optical repeater, as a reset signal to be transmitted. An optical repeater comprising: a signal reproducing means for reproducing a pulse signal that continues for a predetermined period of time based on an incoming reset signal.