| 摘要 |
PURPOSE:To recognize instantly a fault of a system by keeping a busy display of a transmitter to be lighted when a receiver is defective and no answer back signal is returned. CONSTITUTION:When one transmission operation is finished and a terminal logical ICA receives the answer back singnal from the receiver having the same address as that of the transmitter T while the next strobe signal is inputted, the ICA resets an RS latch 16 and stops retransmission. Should the receiver be defective and no answer back signal is returned, the busy display element 20 of each transmitter T keeps lighted thereby recognizing a fault of the system instantly. Since no answer back signal is returned, the transmitter T being a cause to the fault repeats transmission and a transmission display element 19 keeps flickering in response to a transmission data signal, then the transmitter is troubleshooted easily. |
