MONITORING SYSTEM FOR DISTRIBUTION LINE

摘要

PURPOSE:To continue communication between a master station and slave stations even if fault occurs on optical signal lines by providing a receiving level judging unit for the optical signal lines, an input and output circuit converters for switching one of input or output contacts arranged at the secondary of the receiving level judging unit. CONSTITUTION:Assuming faults occur at same positions on optical signal lines 3, 4, provision of signals from rightward optical signal lines 4 to slave stations K1-K9 is interrupted and signals are provided from the leftward optical signal lines 3. Consequently, the circuit is switched such that the output signal advances while being inverted rightward by means of an optical signal 4. Since provision of leftward optical signals 3 to the slave stations K1-Kn is interrupted, signals are provided rightward through the optical signal lines 4 and the circuit is switched such that the output signal advances while being inverted by means of the optical signal line 3.