| 摘要 |
PURPOSE:To detect a broken optical fiber by deciding whether a received optical signal is an optical signal from an opposite station or a signal returned resulting from a reflected optical signal from its own station. CONSTITUTION:The above system consists of a transmission section 100, a reception section 200, an optical coupler 300 and an optical fiber 400. The signal sent from its own station uses a selection means 20 to select a transmission signal, the signal is sent in the original state, a signal from an opposite station is given to a transmission signal state change means 10A, in which the state is changed and the resulting signal is selected and sent by a selection means 20A, after the signal received by its own station is converted into an electric signal at a photoelectric conversion means 50, a state detection means 60 decides whether the signal whose state is changed or the signal whose state is unchanged and decides it to be a broken optical fiber when the signal is the signal whose state is unchanged. |
