| 摘要 |
<p>PURPOSE:To enable the fault position searching for the repeater even at the transmission line featuring the DC breaking property, by using the data pattern in which even numbers of ''1'' signal and the ''0'' signal of the same number of the ''1'' signal emerge continuously and alternately for the data pattern of the monitor signal. CONSTITUTION:The monitor signal production circuit of the end office produces the signals of the RZ-type which features basically the data pattern of ''1100'' along with the data pattern obtained by eliminating ''1'' signal K out of the preceding data pattern via the frequency allotted to the repeater which is to be the subject of the fault searching. On the other hand, the pass bands different from each other are set previously for band pass filter 26 of each repeater, and the monitor signals featuring the disturbed data pattern are transmitted in sequence to the transmission line with the allotment frequency. Thus both the frequency and the level can be known for the answer signal sent back from monitor line 27. In such way, the position can be detected for the faulty repeater.</p> |
