JPH05347588A - Monitoring system for connection of optical transmission line - Google Patents

Abstract

PURPOSE:To detect the connection or disconnection between an optical transmitting device and an external optical transmission line and also to enable the control of transmission, stop of transmission, etc., of the optical data. CONSTITUTION:When the optical signals having the components of wavelengths lambda1 and lambda2 are outputted to an optical connector 30 from a light emitting element for transmission use 21 through an optical fiber cable 23. Thus an optical connector 40 containing a band pass filter lets the optical signal of the wavelength lambda1 transmit and lets the optical signal of the wavelength lambda2 reflect respectively. In a disconnection state of the connector 40, the optical signal of the wavelength lambda2 is not received by a monitoring light receiving element for monitoring use 22. The output current showing the receiving states of both optical signals of wavelength lambda1, lambda2 is converted into the voltage by a current/voltage converter 50. This voltage is compared with the reference voltage 13 by a voltage comparator 60 for detection of the connection or disconnection of an optical fiber cable 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmission line connection monitoring system for use in an optical transmission system and for monitoring the connection state of an optical transmission line connected to an optical transmitter.

[0002]

2. Description of the Related Art Conventionally, in an optical transmission system, no example has been found of monitoring the connection state between an optical transmission device and an optical transmission line. Therefore, the connection state between the optical transmission device and the optical transmission line,
In other words, it is impossible to detect connection or non-connection, so
There is also no control of sending or stopping of optical data when not connected.

[0003]

As described above, in the conventional optical transmission device in the above-described conventional optical transmission system, since the connection state with the optical transmission line is not monitored, the optical transmission device and the external optical transmission line are not monitored. There is a problem in that it is not possible to detect the connection with or disconnection from, and it is not possible to control the transmission or stop of transmission of optical data in the connection or non-connection.

The present invention solves the problems in the prior art as described above, and it is possible to detect the connection / disconnection between the optical transmission device and the external optical transmission line, and the optical data is sent out by this detection. The purpose is to provide an optical transmission line connection monitoring method that enables control such as transmission stop.

[0005]

In order to achieve the above object, in the optical transmission line connection monitoring system according to the present invention, light emitting means for outputting optical signals of the first and second wavelengths. And a light receiving means for receiving the first optical signal and two optical signals of the second wavelength which are input by reflection after transmission, and for outputting a current thereof, and an optical transmitting means for transmitting the optical signal from the light emitting means. And an optical signal is input from the optical transmission means, the optical signal of the first wavelength is passed, and the signal is sent to the external optical transmission line to be connected,
And, an optical connecting means having a bandpass filter for reflecting the optical signal of the second wavelength, returning it to the optical transmission means and transmitting it, and a first optical signal and two lights of the second wavelength by reflection after transmission. The configuration is provided with a detection unit that detects the connection state between the optical connection unit and the external optical transmission line from the output current value from the light reception unit that receives the signal. And the detection means is
The current / voltage conversion means for converting the output current value from the light receiving means into a voltage value, the voltage value from the current / voltage conversion means, and the set voltage are compared to connect the optical connection means and the external optical transmission line, A voltage comparing means for sending an output signal indicating non-connection, or the detecting means detects an output current value from the light receiving means, and connects the optical connecting means and the external optical transmission line from the detected current value, The configuration is provided with a current value / connection determining means for determining non-connection. Further, the optical transmission line connection monitoring system of the invention of claim 4 is, in addition to the configuration of claim 2 or 3,
The structure is provided with a display unit that distinguishes between the connection and non-connection of the optical connection unit and the external optical transmission line.

[0006]

According to the optical transmission line connection monitoring system of the present invention having the above-mentioned structure, the output current value from the light receiving means which receives the first optical signal and the two optical signals of the second wavelength due to the reflection after transmission is determined from the output current value. Detects the connection state of the optical connection means and the external optical transmission line,
Further, the connection / non-connection between the optical connection means and the external optical transmission line is displayed separately, and the connection / non-connection between the optical transmission device and the external optical transmission line is detected. It is possible to control the stop.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the optical transmission line connection monitoring system of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of the embodiment. In FIG. 1, this optical transmission device 10
Has an optical transmission module 20 with an optical output monitor, and the optical transmission module 20 with an optical output monitor has a light emitting element 21 for transmission and a light receiving element 22 for monitoring. The optical fiber cable 23, the optical connector 30 optically connected to the optical fiber cable 23, and the bandpass filter (P
BF) -equipped optical connector 40. The optical connector 40 with a bandpass filter is provided with a bandpass filter (PBF) 41 that passes an optical signal of wavelength λ ₁ and reflects an optical signal of wavelength λ ₂ .

Furthermore, the output current from the optical fiber cable 42 which is an external optical transmission line and the monitor light receiving element 22 is input, and the output current is converted into a voltage proportional to the current value and output. It has a circuit 50 and a voltage comparison circuit 60 which outputs an output signal in which a reference voltage 13 having a voltage value V _th is set and a voltage output from the current / voltage conversion circuit 50 is compared.

Next, the operation of this embodiment will be described. The transmitting light emitting element 21 in the optical transmission module 20 with an optical output monitor inputs an input signal, and outputs an optical signal 11 having wavelengths λ ₁ and λ ₂ as components through the optical fiber cable 23 from the optical connector 30. The optical signal 11 is output to the optical fiber cable 42 by connecting the optical connector 30 and the optical connector 40 with a bandpass filter.

Optical connector 40 with bandpass filter
Transmits an optical signal of wavelength λ ₁ of the optical signal 11, and
Bandpass filter 41 for reflecting the optical signal of wavelength λ ₂
Thus, only the wavelength λ ₁ of the optical signal 11 is transmitted to the optical fiber cable 42, the wavelength λ ₂ is reflected, and the optical connector 30 outputs the optical signal 12 as the optical signal 12 to the optical transmission module 2 with an optical output monitor.
It is returned to 0 and sent. The monitor light-receiving element 22 in the optical transmission module with optical output monitor 20 receives the multiplexed optical signal of the optical signal 11 and the optical signal 12, and detects the optical signal level of the optical signal 11 and the optical signal of the optical signal 12. A current I _{1 + 2} proportional to the level of the optical signal obtained by adding the levels is output. When the optical connector 30 and the optical connector 40 with a bandpass filter are not connected, the monitor light receiving element 22 receives only the optical signal 11 because the optical signal 12 is not reflected by the bandpass filter 41, and the level thereof is reached. It outputs a proportional current I ₁ .

The current / voltage conversion circuit 50 converts the current output from the monitor light receiving element 22 into a voltage having a magnitude proportional to the current value and outputs the voltage. That is, the output voltage V _{1 + 2} is output from the current / voltage conversion circuit 50 when the input current is I _{1 + 2} , and becomes V ₁ when the input current is I ₁ . Here, the magnitude relationship between the output voltages V _{1 + 2} and V ₁ is the same as the magnitude relationship of the level of the optical signal received by the monitoring light receiving element 22, and thus V _{1 + 2} > V ₁ .

In the voltage comparison circuit 60, the reference voltage 13 having the voltage value V _th is set. Reference voltage 1 of this voltage value V _t h
3 and the voltage output from the current / voltage conversion circuit 50,
The result that the relationship is V _{1 + 2} > V _th > V ₁ is output.
That is, when an optical transmission line from the outside, that is, an optical fiber cable 42 is connected to the optical transmission device 10 using the optical connector 40 with a bandpass filter, the voltage input to the voltage comparison circuit 60 is V _{1+. 2} becomes the reference voltage 13, and the output of the comparison result represents “V _{1 + 2} > V _th ”. When the optical transmission line is not connected to the optical transmission device 10, the voltage input to the voltage comparison circuit 60 is V ₁ and the reference voltage 13, and the output of the comparison result represents "V ₁ <V _th ". In the output signal from the voltage comparison circuit 60, "V _{1 + 2} >"
V _th ”and“ V ₁ <V _th ”can detect connection / disconnection of the optical fiber cable 42, which is an external optical transmission line, to the optical transmission device 10.

Various controls based on "V _{1 + 2} > V _th " and "V ₁ <V _th " in the output signal from the voltage comparison circuit 60 which detects the connection / non-connection of the optical fiber cable 42, For example, it becomes possible to control the connection and disconnection of the optical fiber cable 42, the transmission of optical data, and the stop of transmission.

[0014]

As described above, according to the optical transmission line connection monitoring system of the present invention, the output current value from the light receiving means that receives the first optical signal and the two optical signals of the second wavelength due to the reflection after transmission. The connection state between the optical connection means and the external optical transmission line is detected, and the connection / non-connection between the optical connection means and the external optical transmission line is displayed separately, and the connection between the optical transmission device and the external optical transmission line is displayed. ，
The non-connection is detected, and this detection has an effect of enabling control such as transmission and stop of transmission of optical data.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration in an embodiment of an optical transmission line connection monitoring system of the present invention.

[Explanation of symbols]

 10 Optical Transmission Device 20 Optical Transmission Module with Optical Output Monitor 21 Transmitting Light Emitting Element 22 Monitoring Photosensitive Element 23 Optical Fiber Cable 30 Optical Connector 40 Optical Connector with Bandpass Filter 41 Bandpass Filter 42 Optical Fiber Cable 50 Current / Voltage Conversion Circuit 60 voltage comparison circuit

Claims (4)

[Claims] 1. A light emitting means for outputting an optical signal of a first and a second wavelength; and a light receiving means for receiving the first optical signal and two optical signals of a second wavelength inputted by reflection after transmission, The light receiving means for outputting the current, the light transmitting means for transmitting the light signal from the light emitting means, and the light signal from the light transmitting means are input, and the light signal of the first wavelength is passed to be connected. Optical connection means having a band-pass filter for transmitting to the external optical transmission line, reflecting the optical signal of the second wavelength and returning to the optical transmission means, and transmitting the first optical signal and after the transmission. A detecting means for detecting the connection state between the optical connecting means and the external optical transmission line from the output current value from the light receiving means that has received two optical signals of the second wavelength due to the reflection of light. Optical transmission line connection monitoring method. 2. The detecting means compares the output current value from the light receiving means into a voltage value and the current / voltage converting means, and the voltage value from the current / voltage converting means is compared with the set voltage to establish an optical connection. The optical transmission line connection monitoring system according to claim 1, further comprising a voltage comparison unit that outputs an output signal indicating connection / disconnection between the unit and the external optical transmission line. 3. The detection means includes a current value / connection determination means for detecting an output current value from the light receiving means and determining whether the optical connection means and the external optical transmission line are connected or not based on the detected current value. The optical transmission line connection monitoring method according to claim 1. 4. The optical transmission line connection monitoring system according to claim 2 or 3, further comprising display means for displaying whether the optical connection means and the external optical transmission path are connected or not.