JPH0565143U - Optical data transmission device - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain an optical data transmission device capable of easily detecting an optical fiber disconnection. [Structure] When the transmission data is "1", an optical signal is output to the first optical fiber 3a. When the transmission data is "0", an optical signal is output to the second optical fiber 3b. When the received data outputs of the first optical receiver 4a and the second receiver 4b are both data "0", the optical fiber disconnection detection circuit 7 outputs an optical fiber disconnection signal. [Effect] An optical fiber disconnection signal independent of transmission data is output.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical data transmission device for transmitting information using optical signals.

[0002]

[Prior Art]

 FIG. 3 is a diagram showing a conventional optical data transmission device. In the figure, 1 is a light emitting element that generates an optical signal, 2 is a light emitting element drive circuit that controls light emission and extinction of the light emitting element 1 according to transmission data, 3 is an optical fiber that transmits an optical signal, and 4 is received light An optical receiver for reproducing an original electric signal from a signal, 5 is a transmission data line for inputting transmission data, and 6 is a reception data line for outputting reception data. Further, FIG. 4 is a diagram showing operation waveforms of respective parts in the conventional optical data transmission device. In the figure, A is a transmission data waveform of the transmission data line 5, B is an optical signal waveform transmitted by the optical fiber 3, and C is a reception data waveform of the reception data line 6.

Next, the operation will be described. The light emitting element drive circuit performs control such that the light emitting element 1 is “lighted” for the data “1” of the transmission data and the light emitting element 1 is “quenched” for the data “0”, and “1/0” of the transmission data is obtained. The optical signal is turned “ON / OFF” corresponding to “. An optical waveform B is generated for the transmission data waveform A, and this optical waveform is guided to the optical receiver 4 by the optical fiber 3. The optical receiver 4 reproduces and outputs data "1" for the optical signal "ON" and data "0" for the optical signal "OFF". Therefore, for the optical waveform B, the received data waveform C is reproduced and output. By the way, when the transmission data is “0”, the optical signal received by the optical receiver 4 is “OF F”, while when the optical fiber 3 is disconnected, the optical signal received by the optical receiver 4 is “OFF”. Therefore, the transmission data “0” and the optical fiber disconnection cannot be distinguished. For example, in FIG. 4, when the optical fiber 3 is broken at time T, the received data waveform C remains data "0".

[0004]

[Problems to be solved by the device]

 Since the conventional optical data transmission device is configured as described above, there is a problem that the transmission data "0" and the optical fiber disconnection cannot be distinguished.

The present invention has been made to solve the above problems, and an object thereof is to obtain an optical data transmission device capable of easily detecting a break in an optical fiber.

[0006]

[Means for Solving the Problems]

 An optical data transmission device according to the present invention uses two optical fibers to guide an optical signal to a first optical fiber for transmission data "1" and to a second optical fiber for transmission data "0". It transmits the signal and outputs an optical fiber disconnection signal when both optical fibers have no optical signal at the same time on the receiving side.

[0007]

[Action]

 Since the optical data transmission device according to the present invention outputs an optical fiber disconnection signal independent of transmission data, the optical fiber disconnection can be easily detected.

[0008]

【Example】

 Example 1. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 1, 5 and 6 are the same as the above conventional device. Reference numeral 7 is an optical switch for guiding and outputting the optical signal of the light emitting element 1 to the first or second output port according to the transmission data, and 8 is an optical switch control circuit for controlling the operation of the optical switch 7 by the transmission data. Reference numeral 3a is a first optical fiber connected to the first optical output port of the optical switch 7 for transmitting an optical signal, and 3b is connected to a second optical output port of the optical switch 7 for transmitting an optical signal. The second optical fiber 4a is connected to the first optical fiber 3a, and the first optical receiver 4b reproduces and outputs an electric signal from the optical signal. The optical signal 4b is connected to the second optical fiber 3b. Is a second optical receiver for reproducing and outputting an electric signal from the optical fiber, and 9 is a case where the optical outputs of both the first optical receiver 4a and the second optical receiver 4b have no optical signal at the same time. Optical fiber disconnection detection circuit, 0 is the optical fiber disconnection signal line for outputting the optical fiber break detection circuit 9. FIG. 2 is a diagram showing operation waveforms of respective parts in one embodiment of the present invention. In the figure, A is exactly the same as the conventional device. D is the first optical signal waveform transmitted through the first optical fiber 3a, E is the second optical signal waveform transmitted through the second optical fiber 3b, and F is from the first optical receiver 4a. The first received data waveform output, G is the second received data waveform output from the second optical receiver 4b, and H is the waveform of the optical fiber disconnection signal line 10 output from the optical fiber disconnection detection circuit 7. Is.

Next, the operation will be described. The optical switch drive circuit 8 guides the optical signal generated by the light emitting element 1 to the first optical fiber 3a when the transmission data is "1" and to the second optical fiber 3a when the transmission data is "0". Therefore, the optical signal waveform D transmitted through the first optical fiber 3a becomes the optical signal "ON" for the transmission data "1", the optical signal "OFF" for the transmission data "0", and the second signal. The optical signal waveform E transmitted by the optical fiber 3b becomes the optical signal "OFF" for the transmission data "1" and the optical signal "ON" for the transmission data "0". If the second optical fiber 3b is broken at time T for some reason, the optical signal transmitted by the second optical fiber 3b is turned "OFF", and the optical signals of the first and second optical fibers are turned off. The waveforms D and E are in the "OFF" state at the same time. Since the first and second optical receivers 4a and 4b both output data "1" for the optical signal "ON" and data "0" for the optical signal "OFF", they are usually The output data of either one of the first and second optical receivers is "1". However, when an optical fiber disconnection occurs, the output data of both the first and second optical receivers 4a and 4b become "0". At this time, the optical fiber disconnection detection circuit 9 outputs the optical fiber disconnection signal H.

Example 2. Although the received data is extracted from the first optical receiver in the above embodiment, the output of the second optical receiver may be logically inverted and extracted as the received data.

[0011]

[Effect of the device]

 As described above, according to the present invention, since the optical fiber disconnection signal independent of the transmission data is output, the optical fiber disconnection can be easily achieved.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing operation waveforms of respective parts in one embodiment of the present invention.

FIG. 3 is a diagram showing a conventional optical data transmission device.

FIG. 4 is a diagram showing operation waveforms of respective parts in the conventional optical data transmission device.

[Explanation of symbols]

 1 light emitting element 2 light emitting element drive circuit 3 optical fiber 3a first optical fiber 3b second optical fiber 4 optical receiver 4a first optical receiver 4b second optical receiver 5 transmission data line 6 reception data line 7 Optical switch 8 Optical switch control circuit 9 Optical fiber disconnection detection circuit 10 Optical fiber disconnection signal line A Transmission data waveform B Optical signal waveform C Received data waveform D First optical signal waveform E Second optical signal waveform F First reception Data waveform G Second received data waveform H Optical fiber disconnection signal waveform

Claims (1)

[Scope of utility model registration request] 1. A light emitting element for generating an optical signal and a first optical signal connected to the light emitting element corresponding to transmission data.
Alternatively, an optical switch for guiding and outputting the optical switch to the second output port, an optical switch control circuit for controlling the optical switch, and first and second optical ports connected to the first and second output ports of the optical switch for transmitting optical signals, respectively. A second optical fiber, and first and second optical signals for reproducing an electric signal corresponding to the presence / absence of an optical signal.
Optical transmission comprising an optical receiver of 1) and an optical fiber disconnection detection circuit which compares the reproduced signals of the first and second optical reception signals and outputs an optical fiber disconnection signal when there is no optical signal in both. apparatus.