| 摘要 |
PURPOSE:To detect easily the abnormality of each station and transmitting cable circuit by providing a data link device having diagnosing function in each station of a data link system. CONSTITUTION:A data link device 2 provided with a receiver 3, demodulating circuit 4, transmission, receiving controlling circuit 5, modulating circuit 6, transmitter 7, and a switch 8 for bypass to send out directly to a received signal to the transmitter is provided in each station of a data link system. For instance, some station is used as a master station and the another station is used as a slave station 2S, and the two stations are connected by transmitting cables 1MS, 1SM. A switch 8S of the slave station is closed, and transmission data are sent out from the transmission and receiving controlling circuit 5M of the master station. The transmission data returns to the circuit 5M through the modulating circuit 6M, transmitter 7M, cable 1MS, receiver 3S, switch SS, cable 1SM and a demodulator 4M. The circuit 5M compares transmission data with receiving data and diagnoses its quality. |
