| 摘要 |
PURPOSE:To detect the presence of a broken optical cable in the case of optical communication by the one cable. CONSTITUTION:A signal received by a reception circuit (RX) 14 in the absence of optical input at a receiver side is converted by a serial/parallel conversion circuit 13 and latched by a latch circuit and its output is set to a high or a low prescribed level at a receiver side. A latch circuit 3 at a sender side latches a parallel signal, a parallel/serial conversion circuit 4 converts it and a transmission circuit (TX) outputs the signal to the reception side and the reception output without the optical input in the signal and a data in the opposite level are sent and a line monitor bit is set and the data is sent. Thus, when the optical transmission is implemented normally, the line monitor bit at the receiver side and the output of the optical reception circuit reach a different level and when an optical cable is broken due to any cause, since the line monitor bit and the output of the optical reception circuit reach the same level, then the broken line is detected. |
