| 摘要 |
PURPOSE:To manage with only one optical transmission path, to improve reliability, and to lower cost, by applying redundant constitution on an optical transmission/reception part. CONSTITUTION:Assuming that a fault occurs in a 0 system optical signal- electrical signal conversion part 3, a 0 system fault signal 111 is sent to a selection decision circuit 7, and a 0 system-1 system switching control signal 117 is transferred to a selection circuit 9, then, an output electrical signal 118 is converted to a 1 system electrical signal 108. Now, assuming that the fault occurs in a 0 system electrical signal-optical signal conversion part 5, a 0 system fault signal 113 is sent to a selection decision circuit 8, and a 0 system optical signal 105 is stopped at the circuit, and decision to send a 1 system optical signal 106 is performed, and the 0 system optical signal 105 is stopped by a 0 system control signal 115 and 1 system control signal 116, then, the 1 system optical signal 106 is sent out. Thereby, an optical signal 102 outputted from an optical multiplexer 2 becomes the 1 system optical signal 106. |
