| 摘要 |
PURPOSE:To decide the transmission direction at an interface by allowing a photoelectric conversion means to convert its reception optical signal into an electric signal in a timing when a receiver in an input output port is not driven and outputting the signal from a driver. CONSTITUTION:A signal detection circuit 14 is interposed between an optical port 13 and an input output port 11, and the circuit 14 informs it to an output control circuit 15 that the optical signal received by the optical port 13 is outputted while being converted into an electric signal. The circuit 15 is connected to the port 11 to detect the presence of an input data and an output data from the port 11 and drives a receiver R and a driver D selectively. An optical signal received at the circuit 15 in a timing when the receiver R is not driven is sent to the driver D from the optical port 13 while being converted into an electric signal and outputted through a transmission line A, but when the receiver R is driven, the driver D is not driven. When a signal is sent from the receiver R to an optical cable L1, the signal sent from an optical cable L2 is not sent to the 2-way signal line A. |
