JPH02183637A - Optical transmitter - Google Patents

Abstract

PURPOSE:To avoid disable detection due to detouring via an optical filter by detecting the interruption of an input optical signal through the coincidence between a transmission signal and the output of a photoelectric converter. CONSTITUTION:The transmitters are provided respectively with electrooptic converters E/L 41, 42, photoelectric converter L/E 51, 52, optical filters LF 61, 62, and comparators CMP 81, 82 composed of gate circuits or the like. Transmission signals SS1, SS2 and outputs of the L/E 51, 52 are compared individually and when they are coincident, alarm signals AL1, AL2 are sent and control signals CS1, CS2 are given to the E/L 41, 42. Thus, if an input optical signal from an optical transmission line 3 is interrupted due to the fault of the optical transmission line 3 or an opposite party, the output of the L/E 51 or 52 due to the detouring of the E/L 41 or 42 via the LF 61 or 62 is only the transmission signals SS1 or SS2 and the results of comparison of the CMP 81 or 82 are coincident with each other. Thus, the interruption of the input optical signal is detected and the alarm signal AL1 or AL2 is sent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical transmission device that performs bidirectional communication using a wavelength multiplexing method.

[Conventional technology]

FIG. 2 is a block diagram of a conventional example, in which the own station 1 and the other station 2 are connected to each other by an optical transmission line 3, and each station 1.2 has a transmission number 4 88. , ss, into an optical signal (hereinafter referred to as w/L) 41.4
2. Photoelectric converters (hereinafter referred to as L/F) 5+ and 5* that convert input optical signals to receiver No. 4 R8, R82 are provided, and an optical filter (hereinafter referred to as L/F) 5+ and 5* is provided between these and the optical transmission line 3. Below, L
F) 61.6□ intervenes and sends out each output of "/ L4 II 42 to the optical transmission line 3, while demultiplexing the input optical signal from the optical transmission line 3, and sending this demultiplexed output to the L/F ,51.52
It is meant to be given to

Therefore, by making each output wavelength of E/L41.42 different, bidirectional communication by wavelength multiplexing is performed.

In addition, in order to detect that the input optical signal is disconnected due to an abnormality in the optical transmission line 3 or the other party, each L/! E5t, 5
Is there an optical input disconnection detector (hereinafter referred to as 0FD) attached to 2? > ,
7! is provided, and when it detects a disconnection of the optical input signal, it sends out alarm signals AL, , ALs, and in response, the E/
Control signal csl to L4s, 42.

Give cS2, E/L 4. , 42 are blocked.

[Problem to be solved by the invention]

However, there is a wraparound between B/L 41* 42 and L/E 51, 52 via LF61162,
Even if the input optical signal is disconnected due to an error in the optical transmission line 3 or the other party, the output of the own E/L 41 or 42 will remain LF.
6. or 62 via t, , #:5. or 52, this becomes the input to 0FD7tt or 72, resulting in the disadvantage that it is not possible to detect disconnection of the input optical signal.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention is configured by the following means.

In other words, in the above-mentioned optical transmission device, transmitter No. 4 and L/
Comparing means is provided for comparing the output of E and detecting a disconnection of the input optical signal based on the coincidence of the comparison results.

[Effect]

Therefore, if the input optical signal is interrupted, the input optical signal will be recirculated through the LF! Since the output of 7L/g is the same as that of transmitter No. 4, the comparison results match, and it is therefore possible to reliably detect the interruption of the input optical signal.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to the block diagram of FIG. 1 showing an embodiment.

In the same figure, g/L4゜42, L
/F251, 52, LF 8+ + 62 are provided, and a comparator (hereinafter referred to as CMP) 8t + 8m composed of a gate circuit, etc. is provided, which allows transmission No. 4 SS+, SS2 and L/E 5+,
52 outputs respectively, and when the comparison results match, alarm signals ALU and AL2 are sent out, and E/L
Control signals CS 1 + CS 2 are provided to the terminals 41 and 42.

Therefore, if the input optical signal from the optical transmission line 3 is cut off due to an abnormality in the optical transmission line 3 or the other side, the own f:/L41 or 42 via LF 6+ or 61
The output of L/g5+t or 52 due to the input from is only the transmission No. 4 SSs or 882, and CMP8+ or 8! The results of the comparison match, so that disconnection of the input optical signal is detected and an alarm signal AL is generated.

! or AL.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, the disconnection of the input optical signal train is detected by matching the output of the transmitter No. 4 and the photoelectric converter. In addition, since the comparison means using a gate circuit or the like is used, the objective P can be achieved with a simple configuration, and remarkable effects can be obtained in optical transmission devices for various uses.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional example. 3... Optical transmission line, 41.42... Electro-optical converter, 58.5z... Photoelectric converter, 6162...
...Optical filter, 8t+8z ...Comparator, SS+
, 832...Transmission No. 4.

Claims (1)

[Claims] an electro-optical converter that converts a transmitted signal into an optical signal; a photoelectric converter that converts an input optical signal into a received signal; In the optical transmission device, the optical transmission device includes an optical filter that transmits the output of the transmitter to the optical transmission line and also supplies an input optical signal from the optical transmission line to the photoelectric converter, in which the transmit signal and the output of the photoelectric converter are connected to each other. An optical transmission device characterized by comprising a comparing means for comparing and detecting a disconnection of the input optical signal based on a coincidence of the comparison results.