| 摘要 |
PURPOSE:To enable failure retrieval in on-line, by alternately outputting coarse and fine pattern signals every half period of station assignment frequency, in a failure retrieval system of transmission line using binary code. CONSTITUTION:Speed conversion is made at a speed conversion circuit VC1 for inputted data, synchronizing bit is inserted and inputted to 3B, 4B conversion circuit BCT, and a dense pattern mode 1 and a coarse pattern mode 2 signals are outputted alternately every half period of signal frequency from a clock source f1 and transmitted to a transmission line L with precoding. In a relay device, the output of a playback device is brached and the signal component assigned to the station itself is picked up by inputting it to TFF and BPF and transferred to a terminal station. At a reception terminal station, decoding is made at a decoder DEC and converted into the signal in original bit number at an inversion circuit RECT, the speed conversion and synchronizing bit rejection are made at the speed conversion circuit VC2 to obtain the original data. |
