| 摘要 |
PURPOSE:To extract an optical signal from a prescribed communication destination, to reduce the cost and to realize high reliability by executing inverse conversion and setting a signal level at every communication destination when conversion from an electric signal to the optical signal is not executed in an optical converting means by forming the optical signal to be transmitted to a pulse. CONSTITUTION:The electric signal of plural pulse trains in a prescribed time corresponding to the respective bits of the optical signal generated by a transmitting means is converted to the optical signal with the optical converting means and the signal is supplied through a light branching means to an optical transmission line. In reception, the optical signal supplied from the communicating destination to the optical transmission line is supplied through the light branching means to the optical converting means and when the electric signal supplied from the transmitting means is not converted to the optical signal in the optical converting mean, the optical signal is converted to the electric signal and supplied to an extracting means. In the extracting means, the signal level corresponding to the communicating destination is detected from this electric signal and the optical signal supplied from the prescribed communication destination is extracted. The transmitting means corresponds to a signal control part 36, interface circuit 37, driving circuit 38 and the extracting means corresponds to an maximum position decision circuit 30. |
