SU1677677A1 - Device for locating faults in optic cable - Google Patents

Abstract

The invention relates to a measurement technique and can be used to determine the distance to a damaged optical cable. The aim of the invention is to expand the field of application by providing continuous monitoring of the performance of a multi-fiber optical cable during its operation in a communication system. The device containing the optical receiver 1, the delay line 2, the optical splitter 3.1 and the measuring unit 4, the optical splitters 3.2-3. N, the optical assembly 5, the element And 6, the element NOT 7, the counter 8 faults, the decoder 9, indicator 10, elements OR 11 and 12, and corresponding links. The proposed structure of the device allows you to branch off the information passing through the fiber optic path and use it to continuously monitor the operating state of a multi-fiber optical cable without disrupting the operation of the communication system where this cable operates. 2 Il. (Ls

Description

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The invention relates to a measurement technique and can be used to determine the distance to an optical cable damage.

The purpose of the invention is to expand the field of application of the device by providing continuous monitoring of the performance of a multi-fiber optical cable during its operation in a communication system.

FIG. 1 shows a block diagram of the device; in fig. 2 - timing diagrams for the operation of the device,

The device contains an optical receiver 1, a delay line 2, n optical splitters 3.1-3, n, a measurement unit 4, an optical assembly 5, an AND 6 element, a HE 7 element, a fault counter 8, a decoder 9, an indicator 10, and OR 11 and 12 elements , optical inputs 13.1-13, n devices, inputs 14.1-14, n devices, optical outputs 15,, n devices, inputs 13.1-13.n devices are connected to the input of the corresponding optical splitter 3, the first outputs of which are connected to the corresponding inputs optical assembly 5, and the second outputs are connected to the outputs 15.1-15.p device. The output of the optical assembly 5 is connected to the output of the optical receiver 1, the output of which is connected to the first input element AND 6, the output of which is connected to the first input of the element OR 12 and the input of the fault counter 8, the output of which is connected to the decoder 9, the output of which is connected to the input of the indicator 10 , inputs 14.1-14.P devices are connected to the inputs of the OR element 11, the output of which is connected to the second input of the element OR 12 and to the input of the delay line 2, the output of which is connected to the first input of the measurement unit 4 and through the element 7 to the second input of the AND element 6, you the element stroke OR 12 is connected to the second input of the measurement unit 4.

Measurement unit 4 comprises a trigger 16 connected in series and a meter 17, the first and second inputs of trigger 16 being connected to the corresponding inputs of measurement unit 4.

It is known that communication system interfaces operate on the Request-Response principle. This exchange principle ensures that a single service signal is in the communication line at any time and when several information signals are simultaneously transmitted over several fibers simultaneously. The device is connected to the fibers of an optical cable that operates to transmit signals. Thus, on both sides of the communication line, all the optical fibers of the cable will be continuously monitored in terms of the occurrence of malfunctions from the places of damage and the determination of the distance to these places.

The device is connected to a functioning communication system without interrupting its operation as follows. In part of the optical fiber, optical splitters 3.1-H.P are connected between the output of the optical transmitter and the optical fiber of the communication system cable through the first group of inputs parallel to the input of the optical transmitters of the communication system product, electrical buses are connected, the second ends of these buses are connected to the second group of inputs 14 of the device, essentially the same

0 signals that are transmitted via optical fiber.

The device works as follows.

The signals generated by the transmitting product of the communication system (FIG. 2a) are fed to the inputs of optical transmitters in the communication system and simultaneously through logical buses through the second group of device inputs to the inputs of the element OR 11. From the outputs of optical transmitters through optical fibers Signals are sent to the optical splitters 3.1-Z.p devices through its first group of inputs and then through the group

5 outputs 15 of the device through the optical communication line to the inputs of the optical receivers of the receiving product of the communication system. When a service or information optical signal passes through the optical splitters 3, a part of its energy is branched off and through the optical assembly 5 enters the input of the optical receiver 1. To prevent these signals from the output of the OR 11 element from being received through line 2

5 Entry delay element 7 will receive a signal delayed by a time equal to the formation of a light pulse in the optical transmitter and the delay in the path to the optical splitters 3. C

0 output element NOT 7 inverted signal prohibition is fed to the second input element And 6 (Fig, 2b), the first input of which receives part of the energy of the service or information signal (Fig.

5 26). In this case, the output element And 6 signal will be absent. From the output of the element OR 11, the logical signal is fed to the second input of the element OR 12 and from its output to the second input of the trigger -16 of the measurement unit 4, thereby setting it to

initial O state. The same signal from the output of the delay line 2, delayed by time At, sets the trigger 16 and state 1 to start the countdown of the time interval between the probe pulse and the signal reflected from the damage point of the optical cable (Fig. 2d) The service and information signals transmitted over the optical fiber of the cable are simultaneously used as sounding signals to determine the distance to the damage point of the cable. The pulse reflected from the first point of damage of the optical cable through the first outputs of the optical splitters 3, the optical assembly 5 is fed to the optical receiver 1 (Fig. 2e). From the output of the optical receiver 1, the reflected pulses arrive at the first input cell of the And 5 element. At the second input of the And element b, the prohibition signal in this case is absent. From the output element And 6 the reflected signal is fed to the counter 8 failures to count the number of failures. The output of the counter is connected to the decoder 9, which converts the number of failures into a digital code and then displays it on the indicator 10. After detecting a failure, the distance to the fault location is determined in the optical cable and the failure counter 8 is manually reset.

In addition, from the output of the element 6 through the first input of the element OR 12, the reflected signal from the damage point of the cable enters the second input of the trigger 16 of the measurement unit 4 and sets it to the state O. The output of the trigger 16 is connected to the meter 17 of the measurement unit 4.

The meter 17 measures the pulse duration of the trigger 16, thereby providing a measurement of the distance to the fault or failure directly in units of length.

FIG. 2, the inhibit signal in time is located at the beginning of the installation of the trigger 16 in a single state, which should affect the accuracy of the reference. However, this inaccuracy is compensated by mechanical

the inertia of the gauge used in the gauge 17.

Thus, this device, in addition to determining the distance to the point of damage to the optical to white, allows monitoring the functioning of the optical cable of the communication system without interrupting the operation of the system, thereby increasing its maintainability and reliability. The automatic recording of the number of failures in the optical cable system makes it possible to determine the reliability of data transmission. In addition, the invention allows the control

in a multi-fiber optical cable.

Claims (1)

Apparatus of the Invention A device for determining the distance to an optical damage point. a cable comprising an optical splitter, an optical receiver, a delay line and a measuring unit, the first input of which is connected to the output of the delay line, characterized in that expansion of the field of application, an optical assembly, a p-1 optical splitter, an AND element, an NOT element, two OR elements, a fault counter, a decoder and an indicator, and the inputs n The optical splitters are connected to the corresponding n optical inputs of the device, the first outputs n of optical splitters are connected to the n optical outputs of the device, their second outputs connected to the corresponding n inputs optical assembly, the output of which is through serially connected optical receiver, And element, fault counter and the decoder is connected to the input of the indicator, n electrical inputs of the device are connected to the corresponding n inputs of the first OR element, the output of which is connected to the input of the delay line and the first input of the second element OR, the second the input of which is connected to the output of the element I, and the output to the second input of the measuring unit, the output of the delay line through the element is NOT connected to the second input of the element I. at BUT Fig 2