| 摘要 |
PURPOSE:To establish an optical communication path and to easily alarm the fault of transmission in communicating by always monitoring a fixed bit pattern signal at a reception side with transmission data from a transmission side. CONSTITUTION:A reception circuit 9 always monitors the fixed bit pattern signal FLM inputted at every constant cycle. And in the case of receiving the signal FLM periodically, the reception of the data is permitted, and in the case of receiving an erroneous fixed bit pattern signal FLM due to the fault of a transmission path, etc., the reception of the data is interrupted, and at a time when the next fixed bit pattern signal is received correctly, the reception of the data is restarted. Also, state transition by a state transition device in the reception circuit 9 is reported to a state display circuit 10, and the state display circuit 10 reports a transition state being set by a display lamp or a buzzer, etc., to an operator corresponding to the transition state. In such a way, the operator can recognize the fault of the transmission in a state where an optical transmission path is established easily not only at the time of starting optical communication. |
