DETECTING SYSTEM FOR FAULT POSITION OF OPTICAL CABLE TRANSMISSION SYSTEM

摘要

PURPOSE:To increase the accuracy of detection for an fault position, by inserting an optical cable connection case to every production unit length of an optical cable, branching a part of the arrived signal in the connection cable to perform a photoelectric conversion and transmitting the electric signal obtained through the photoelectric conversion to a transmission end office. CONSTITUTION:For a search of a fault position, the normal transmission signal is discontinued for transmission to a transmission line and a fault position detecting signal generator 10 is connected to a transmission signal input terminal 2. An optica end office device 3-1 gives an electrooptical conversion to the signal which is supplied to the terminal 2 and supplies it to an optical fiber 5. Then a part of the arrived signal is branched and extracted by an optical coupler 21 of an optical cable connection case 7 and then converted into an electric signal through a photoelectric converter 22. This electric signal is amplified by an amplifier 23 and its low frequency signal FL is filtered through a low-pass filter 24 to be supplied to a modulator 26. The output of the modulator 26 is connected to a metallic conductor 6 within an optical cable via a coupler 27 and then transmitted to a coast station 1-1.