| 摘要 |
<p>PURPOSE:To execute easily and exactly a search of a repeater fault by a signal which satisfies a CMI code rule, by constituting so that a monitoring station converts a signal to a code by the CMI code rule by a CMI converting circuit and sends it out, and each repeater station turns back and connects upper and lower transmission lines when a sum-converted signal contains a specified frequency component. CONSTITUTION:A search code generating circuit is constituted of a pattern generator 11, a variable frequency oscillator 12 and an exclusive OR circuit 13, and as for an output code of the circuit concerned, the generation probability of ''1'' is varied to (m) and 1-m. Also, a difference converting circuit is constituted of a delaying circuit 14 and an exclusive OR circuit 15, and difference conversion of the output signal of the exclusive OR circuit 13 is executed. In a repeater station 2, an output signal 45 of a sum-converting circuit 32 is detected by a detector 34 through a band-pass filter 33. A receiving signal discriminated and reproduced by a signal receiving part 311 is turned back and connected to a transmission line in the opposite direction through a signal transmitting part 511, and is sent out to a monitoring station 1.</p> |
