| 摘要 |
PURPOSE:To make a test signal needless and to improve a reliability by executing a fault detection by using a real transmission signal in the same state as a real action at the time when the reception signal does not exist. CONSTITUTION:A signal obtained by decoding an output from a selection circuit 7 in a decoding circuit 8, which selection circuit 7 inputs a transmission signal output obtained by encoding a transmission signal input in an encoding circuit 2 and a reception signal and selects to output either of the transmission signal output and the reception signal input with a control signal outputted from a reception signal detection circuit 6, is compared with a signal from a delay circuit 4 so as to execute the fault detection with the control signal outputted from the reception signal detection circuit 6. And with the control signal outputted from the reception signal detection circuit 6, it is decided whether the signal from the decoding circuit 8 is a transmission signal or a reception signal to make only reception signal be outputted. Thus, the fault detection can be executed by using the real transmission signal in the same state as the real action at the time when the reception signal does not exist. |
