| 摘要 |
PURPOSE:To search plural repeaters for faults simultaneously by one kind of fault search pattern signal, by multiplexing and sending back phase information obtained by dividing the frequency of the fault search pattern signal at each repeater to a monitor station. CONSTITUTION:A fault search pattern generator TPG generates one kind of fault search pattern signal of repetitive frequency (f), and this signal is sent out of a monitor station CT to a transmission line. This fault search pattern signal is frequency-divided by frequency dividers DV of respective repeaters RP1-RPn, and their outputs are passed through low-pass filters LPF and then amplitude- multiplexed by multiplexing parts MUX1-MUXn on time-division basis to send the resulting signal to a monitor station CT. At the monitor station CT, the received signal is demultiplexed by a demultiplexing part DMUX and a phase comparison part PCMP makes phase comparison with the sent signal to obtain fault information on repeaters. |
