Light transmitter-receiver apparatus

摘要

A light transmitter-receiver apparatus for detecting a trouble occurring on a light transmission line and reducing a light output. In a light transmitter-receiver apparatus including a light transmitter section for converting a transmission electric signal into a light signal and sending it, and a light receiver section for converting a light input signal into a reception electric signal, there is provided an output control section including an abnormality detecting means for detecting an abnormality occurring in a reception electric signal and an output level adjusting means for adjusting the magnitude of an output level of the light transmitter section depending upon a detection state of the signal abnormality. Signal abnormality may be detected by a missing of a synchronizing signal contained in the reception electric signal or a signal error occurring in the reception electric signal.