SYSTEM FOR REMOTE LOCATING FAULTS IN A DATA COMMINICATION MEDIUM HAVING REGENERATIVE REPEATERS

摘要

A remote locating system for remote locating the pairs of regenerative repeaters of a bidirectional data transmission line which is interconnected between a monotoring station and a monitored station. The monitoring station comprises a first low frequency generator which generates a first low frequency signal on the forward line channel which is continuously transmitted in the forward direction from the monitoring station to the monotored station in response to the fault detection on the line and a second low frequency generator which generates a second low frequency signal on the backward line channel which is transmitted in the forward direction after the transmission beginning of the first signal. The second signal is modulated by successive pulses, each of which identifies a regenerative repeater pair. The first signal is simultaneously detected in each forward transmission regenerative repeater and controls the connection of the output and the input of the forward and backward transmission regenerative repeaters of each pair. In the backward transmission regenerative repeater of each pair the pulse which identifies the next pair, is detected for connecting the input and the output of the backward regenerative repeaters of the pair and the next pair and for disconnecting the regenerative repeaters of the pair. The first and second low frequency signals are mixed with a digital testing signal which is transmitted from the monitoring station through the connected pair and is monitored between two successive pulses so as to detect the transmission faults of the connected pair or the connected line section.