JPH0541694A - Optical signal transfer method - Google Patents

Abstract

PURPOSE:To obtain the optical signal transfer method capable of up and down optical communication with one optical transmission line without providing a light source in a slave station in the optical signal transfer method between a master station and more than two slave stations and between slave stations. CONSTITUTION:A master station 1 and more than two slave stations 21 to 2n are linked in an optical transmission line 3, and an optical switch 4 is provided on the position corresponding to each slave station among the optical transmission lines 3. Each slave station 21 to 2n takes in an optical signal from the master station 1 and the other slave station. The data from each slave station 21 to 2n are converted into ON-OFF signals according to the data of each slave station 21 to 2n to be sent from the master station 1 by turning an optical switch 4 ON and OFF based on the data of each slave station, the ON signal is sent from the master station 1 and the self station to the slave station on the down side by the optical transmission line 3 at the time of turning ON the optical switch 4, and the OFF signal is sent from the self station to the slave station on the up side while reflecting it on a reflection part 6 of a return fiber 5 to be connected to the optical switch 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical signal transmission method for optical communication between a master station and a plurality of slave stations connected by a one-core optical transmission path, and between the plurality of slave stations. Is.

[0002]

2. Description of the Related Art Conventionally, between a master station 1 having a light source a, a light receiver b, etc. as shown in FIG. 2 and a plurality of slave stations 2 ₁ to 2 _n having a configuration as shown in FIG. when performing optical communication between the slave stations 2 ₁ to 2 _n mutually was as follows. Child station 2 ₁
When performing transmission from to 2 _n, the input signal from the data input interface A of the slave station 2 ₁ to 2 _n in electrical / optical conversion in the laser diode LD, the uplink optical transmission line B, and the downlink optical transmission line C The parent station 1 sends out the slave stations 2 ₁ to 2 _n .
Or when receiving an optical signal from other slave stations 2 ₁ to 2 _n, the optical transmission path B, the slave station 2 ₁ an optical signal transmitted over the C
The signal is converted into an electric signal by the optical / electrical converter D of up to 2 _n and is taken into the data output interface H.

[0003]

However, in the conventional optical signal transmission method, the two optical transmission lines B and C for the upstream and the downstream are required, and the light source is provided for each slave station 2 ₁ to 2 _n. Since the LD has to be provided, there is a problem that the equipment becomes complicated and the cost becomes high.

[0004]

[Object] An object of the present invention is to provide a light source in a slave station when performing optical communication between the master station and the slave stations and between the slave stations by an optical transmission system including the master station and a plurality of slave stations. In addition, another object of the present invention is to provide an optical signal transmission method that enables optical communication through a single optical transmission line.

[0005]

According to the optical signal transmission method of the present invention, a master station 1 and a plurality of slave stations 2 ₁ to 2 _n are connected by an optical transmission line 3 of one core as shown in FIG. by comprising the optical transmission system, the master station 1 and slave station 2 ₁ between to 2 _n, in the optical signal transmission method in optical communication between the slave stations 2 ₁ to 2 _n mutually the optical transmission line 3
An optical switch 4 is provided at a position corresponding to each slave station 2 _{1 to} 2 _n as shown in FIG. 1, and each slave station 2 ₁ to 2 _n is connected to the master station 1 and other slave stations 2 ₁ to 2 _n . An optical signal is taken in from the optical transmission line 3, and the data from each slave station 2 ₁ to 2 _{n is transferred} to the optical switch 4
ON-OF based on the data of the respective slave stations 2 ₁ to 2 _n
When the optical switch 4 is turned on, the light transmitted from the master station 1 is converted into an ON-OFF signal corresponding to the data of the _respective slave stations 2 ₁ to 2 _n , and when the optical switch 4 is turned on, the ON signal is transmitted to the optical transmission line 3 To the slave station on the downstream side from the master station 1 and its own station,
At the time of FF, the OFF signal is reflected by the reflection part 6 of the return fiber 5 connected to the optical switch 4 and transmitted to the slave station on the upstream side of the own station.

[0006]

According to the optical signal transmission method of the present invention, when the optical signal is transmitted from the master station 1 to the slave stations 2 ₁ to 2 _n , the optical signal from the light source a (FIG. 2) in the master station 1 is transmitted. It suffices to transmit from the optical transmission line 3. Any of the slave stations 2 ₁ to 2 _n to other slave stations 2 ₁ to
When transmitting an optical signal to 2 _n , the light transmitted from the light source a of the master station 1 is converted into an ON-OFF signal by turning ON / OFF the optical switch according to the data of the slave station. Incidentally, the data of the slave station is applied to the optical switch 4 from the data input interface 7 shown in FIG. Of the ON-OFF signals, the ON signal is transmitted to the slave station on the downstream side from the own station when the optical switch 4 is ON, and the OFF signal is the termination side of the return fiber 5 when the optical switch 4 is OFF. Is reflected by the reflection part 6 provided in the optical transmission line 3 through the optical switch 4.
And is transmitted to the slave station on the upstream side from the own station. In this case, the OFF signal reflected by the reflector 6 is
Since N-OFF is completely reversed, the slave stations 2 ₁ to 2 _n
ON-O of OFF signal electrically converted by O / E converter 9
The FF is inverted by the inverter 10 and converted into an ON signal.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A slave station 2 used in the optical signal transmission method of the present invention.
_In FIG. 1 showing _{1 to} 2 _n , 3 is an optical transmission line, and 4 is a waveguide type optical switch provided at a position in the optical transmission line 3 corresponding to each slave station 2 ₁ to 2 _n . The optical switch 4 switches between the point p on the downstream side of the optical transmission line 3 and the point q of the return fiber 5 to turn the optical transmission line 3 on and off. Reference numeral 6 denotes a reflecting portion provided at the end of the returning fiber 5, which has a reflecting material coated on the terminating surface of the returning fiber 5, and when the optical switch 4 is turned off, the master station 1
It reflects the light transmitted from. The optical signal transmitted from the master station 1 is fetched from the optical transmission line 3 to each slave station 2 within _one to 2 _n, the optical coupler 11 of Doko station 2 within _one to 2 _n, the optical / electric converter 12 The data is output to the data output interface 13 via. Also,
When transmitting from the slave station 2 ₁ to 2 _n of the respective optical signals to the master station 1 or another slave station 2 ₁ to 2 _n is the data of each slave station 2 ₁ to 2 _n de - through data input interface 7 Driver 8
And the driver 8 is operated by the output from the driver 8 to turn the optical switch 4 on and off. This O
The light transmitted from the master station 1 to the optical transmission line 3 in accordance with N-OFF is turned ON-OFF and converted into an ON-OFF signal.
Of the ON-OFF signals, the ON signal is sent to the optical transmission line 3 when the optical switch 4 is turned ON, and is transmitted from the master station 1 and the local station to the downstream slave station. Further, the OFF signal is sent to the return fiber 5 connected to the optical switch 4 when the optical switch 4 is OFF, reflected by the reflection section 6 of the return fiber 5, and transmitted to the optical transmission line 3 through the optical switch 4. Then, the data is transmitted from the own station to the upstream slave station.

In each slave station 2 ₁ to 2 _n , another slave station 2
_When receiving the optical signal transmitted from _{1 to} 2 _{n, the} following is done. An optical signal transmitted from the upstream side (in the direction of arrow Q in FIG. 1) from any of the child stations that receives the light is extracted by the optical coupler 11 of the child station and converted into an electrical signal by the optical / electrical converter 12 of the child station. Then, the data is output to the data output interface 13. The optical signal transmitted from the downstream side (in the direction of arrow P shown in FIG. 1) from any of the child stations that receive the light is extracted by the optical coupler 15 of the child station and converted into an electrical signal by the optical / electrical converter 9 of the child station. To do. Further, since the received optical signal is the above-mentioned OFF signal, ON-OFF is inverted by the inverter 10 to be converted into an ON signal, which is taken into the data output interface 13 of the received slave station.

[0009]

The optical signal transmission method of the present invention has the following effects. ． Since use of the light from the master station 1 as a light source for transmitting a signal from the slave station 2 ₁ to 2 _n, it is not necessary to install the light source to each slave station 2 within _one to 2 _n, equipment is simplified Also, the cost is reduced. ． Since the direction (upstream, downstream) of the signal light transmitted by the optical switch 4 can be switched, optical transmission in both the up and down directions is possible with the single optical transmission line 3, the optical transmission system is simplified, and the cost is reduced. To do.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a slave station in an optical signal transmission method of the present invention.

FIG. 2 is an explanatory diagram of an optical signal transmission method.

FIG. 3 is an explanatory diagram showing an example of a slave station used in a conventional optical signal transmission method.

[Explanation of symbols]

1 master station 2 ₁ to 2 _n slave station 3 the light transmission path 4 optical switch 5 returns fiber 6 reflecting portion

Claims (1)

[Claims] 1. An optical transmission system in which a master station 1 and a plurality of slave stations 2 ₁ to 2 _n are connected by an optical transmission path 3 of one core,
Master station 1 and slave station 2 ₁ between to 2 _n, in the optical signal transmission method in optical communication between the slave stations 2 ₁ to 2 _n mutually corresponding to each slave station 2 ₁ to 2 _n of the optical transmission line 3 An optical switch 4 is provided at the position, and each slave station 2 ₁ to 2 _n is connected to the master station 1 and other slave stations 2 ₁ to 2 _n.
The optical signal from the optical transmission line 3 is taken in and each slave station 2 ₁ ...
The data from 2 _n is transmitted to the optical switch 4 by the respective slave stations 2 ₁
By ON-OFF based on to 2 _n of data, converts the light transmitted from the master station 1 to the ON-OFF signal in accordance with the data of each slave station 2 ₁ to 2 _n, the optical switch 4
When ON, the ON signal is transmitted to the master station 1 and the slave station downstream from the own station through the optical transmission line 3, and the OFF signal is transmitted when OFF.
An optical signal transmission method, characterized in that a signal is reflected by a reflection section 6 of a return fiber 5 connected to an optical switch 4 and transmitted to a slave station on the upstream side of the own station.