JPH02195752A - Method for bypassing optical loop transmission line - Google Patents

Abstract

PURPOSE:To suppress influence given by an asynchronous state by providing a comparator and a relay, and a performing bypass control while monitoring a source voltage. CONSTITUTION:An input signal is bi-sected by an optical branching filter 2, and one is supplied to an optical switch 1, and the other to the logic part 22 of data transmission equipment 2, and the output of the logic part 22 is issued to an optical fiber cable L' via the switch 1. A driving power source for the switch 1 is supplied from a power source 21 via the contact of the relay 4 excited by a transistor(TR) 11 being turned on by the comparator 10 which compares a reference voltage generated from the power source 21 of the branching filter 2 with the output of the logic part 22. The bypass state of the switch 1 can be formed when the power source 21 is disconnected, etc., and the TR 11 is turned off just before an error occurs in the logic part 22, and the relay 4 is recovered. After that, the output of the logic part 22 via the contact 4a of the relay and a time constant circuit is supplied to the comparator 10 when the power source 21 is supplied, and the power source 21 is supplied after a synchronous stable state is established.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for bypassing an optical loop type transmission line in which data transmission devices are connected in a loop with an optical fiber cable, and particularly relates to a method for bypassing an optical loop type transmission line in which data transmission devices are connected in a loop with an optical fiber cable. This relates to a bypass method for switching between inputting an optical signal to a device and allowing it to pass through as is.0 [Prior Art] Conventionally, this type of bypass method for optical loop transmission lines has been the second method.
As shown in the figure, the optical switch 1 is connected to the optical fiber cables L and L', and the power source 21 of the data transmission device 2 is used as a power source for driving the optical switch 1. When the power source 21 is on, the optical switch 1 is operated. When the optical signal is input to the data transmission device 2 and the power supply 21 is turned off, the optical fiber cables L and L' are connected by bypass.

[Problem to be solved by the invention]

In the conventional bypass method, 1. The configuration was such that the power supply 21 of the connected data transmission device 2 is directly input to the optical switch 1, and when the power is cut off, the optical switch 1 is restored, thereby disconnecting and bypassing the data transmission device 2. . However, when the power supply 21 of the data transmission device 2 is turned off, the voltage drop characteristic is gradual, so it takes about 1 second to enter the bypass state.
During this time, an error occurred in the logic section 22 of the data transmission device 2, causing a problem in that the data on the optical fiber cables L and L' were disturbed. In order to solve this problem, it is possible to make the voltage drop characteristic of the power supply 21 of the data transmission device 2 steeper, but it is not possible to make it steeper because there is a risk of malfunction due to noise and instantaneous power outages. However, this solution was also insufficient. In addition, the power supply 21 of the data transmission device 2
When the power supply 21 is turned on, the logic section 22 starts operating, and it takes about 3 seconds to establish synchronization, but the optical switch 1 operates at the same time as the power supply 21 is turned on and cancels the bypass, so synchronization is achieved. There was a problem in that a disconnected state would spread to the entire loop.

[Means to solve the problem]

The optical loop type transmission line bypass method of the present invention has been made to solve the above-mentioned conventional problems. a logic section connected to one output of the optical splitter; an optical switch to which the output of the logic section and the other output of the optical branching device are connected; and a power source that supplies current to the logic section and the optical switch; When the output of the power supply goes from a normal state to OFF, the logic section turns off the output at the voltage immediately before an error occurs, and when the output of the power supply goes from an OFF state to ON, the output is turned off after a certain period of time has elapsed. It has a comparator configured to turn on, a transistor connected to the output of the comparator, and a relay connected to the emitter of the transistor, and the power source is connected to the optical switch by turning on and off the contacts of the relay. It is designed to turn on and off the input power.

[Effect]

In the present invention, the comparator and relay monitor the power supply voltage of the connected data transmission device, and when the voltage is turned off from a normal voltage state, the data transmission device is disconnected before an error occurs in the logic section, and the data transmission device is put into bypass state. year,
Further, when the power is turned on from the off state, the bypass state is maintained until synchronization is established in the logic section, and after the synchronization is established, the bypass is released.

〔Example〕

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

FIG. 1 is a block diagram of the main parts of an optical loop transmission line for explaining an embodiment of the optical loop transmission line bypass method according to the present invention, and the same parts as those in the previous figure are given the same reference numerals. be. In the figure, 3 is an optical splitter, 4 is a relay, 4a is the first contact of the relay 4, 4b is the second contact of the relay 4,
5 is a diode, 6. T is a resistor, 8 is a diode, 9 is a capacitor, 10 is a comparator, 11 is a transistor, 12 is a resistor, and 13 is a capacitor.

Next, a method of bypassing the optical loop transmission line will be explained using FIG.

First, an input signal from the optical fiber cable L is split into two by the optical branching device 3, one of which is input to the optical switch 1, and the other input to the logic section 22 of the data transmission device 2. Normally, the optical switch 1 moves toward the broken line side, and the output of the logic section 22 is outputted through the optical switch 1 to the optical fiber cable L'. The driving power for the optical switch 1 is supplied through the power supply 21 of the data transmission device 2 and the contacts 4 of the serial relay 14. Also, the output of the power supply 21 of the data transmission device 2 is connected to the diodes 5, 8 and the resistor 6,771.
The voltage is input as a reference voltage to a comparator 10 through a voltage stabilizing circuit consisting of a capacitor 9 and a capacitor 9. Further, in the normal case, the output of the power supply 21 of the data transmission device 2 moves the contact 4a of the relay 4 toward the broken line side, and is directly inputted to the comparator 10 and compared with the reference voltage. The value of the resistor 6°7 is determined so that the voltage of the power supply 21 of the data transmission device 2 decreases and the output of the comparator 10 is inverted at the voltage immediately before an error occurs in the logic section 22 of the data transmission device 2. When the output of comparator 10 is inverted,
When the transistor 11 is turned off, the relay 4 is restored, the contact 4b is moved to the solid line side, and power is no longer supplied to the optical switch 1, so the optical switch 1 is restored and enters the bypass state. When the power supply 21 of the data transmission device 2 is turned on from the off state, the contact 4a of the relay 4 moves toward the solid line side, and the resistor 12. The voltage is input to the comparator 10 through a time constant circuit consisting of a capacitor 13, and compared with a reference voltage. When the power supply 21 of the data transmission device 2 is turned on, the logic section 22 of the data transmission device 2 starts normal operation.
After establishing synchronization, the values of the resistor 12 and capacitor 13 are determined so that the output of the comparator 10 is inverted, and as a result, when the output of the comparator 10 is inverted, the transistor 11 is turned on and the relay 4 is activated. and contact 4b
operates in the direction of the broken line, power is supplied to the optical switch 1, and the optical switch 1 operates in the direction of the broken line, releasing the bypass.

〔Effect of the invention〕

As explained above, according to the present invention, by providing a comparator and a relay, the power supply voltage of the connected data transmission device is monitored, and when the voltage is turned off from a normal state, before the logic section generates an error. It is possible to disconnect the data transmission device and put it into a bypass state. Also, when the power is turned on from an off state, the bypass state can be maintained until synchronization is established in the logic section, and after synchronization is established, the bypass state can be set. Since it can be canceled, the effect on the entire loop can be minimized.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a main part of an optical loop transmission line for explaining an embodiment of the optical loop transmission line bypass method according to the present invention, and FIG. 2 is a block diagram of a conventional optical loop transmission line. be. 1...-Optical switch, 2##--Data transmission device, 2
1...power supply, section, 3...optical splitter, 4b...contact, 5.fog 1--0 resistor, 8.a--fog capacitor, 10-...Lu- Transistor, 1... Capacitor ◎ 2... φ Logic... Relay, 4a.・Diode, 6° diode, 9... ・Comparator, 11 ・・・Resistance, 13

Claims (1)

[Claims] In the bypass method of an optical loop transmission line, which connects multiple data transmission devices in a loop with optical fiber cables and is equipped with an optical switch that bypasses the optical signal by turning on and off the power of each data transmission device, the signal received from the optical fiber cable is an optical branching device that branches an optical signal into two; a logic section connected to one output of the optical branching device; and an optical switch connecting the output of the logic section and the other output of the optical branching device; The logic section and the power supply that supplies the switch current, and when the output of the power supply is turned off from a normal state, the logic section turns off the output at a voltage immediately before an error occurs, and the output of the power supply is turned off. It has a comparator that turns on the output after a certain period of time when it is turned on, a transistor that is connected to the output of the comparator, and a relay that is connected to the emitter of the transistor. A bypass method for an optical loop type transmission line, characterized in that the power input from the power source to the optical switch is controlled to be turned on or off by turning it on or off.