| 摘要 |
PURPOSE:To previously prevent the failure that is caused by a fault of a switching circuit and affects the operation of a system by providing a diagnostic means of a diagnostic switching circuit interlocking a main switching circuit. CONSTITUTION:When a higher rank device recognizes a fault of a lower rank device, the former device transmits a switch instruction signal 29 to a switch control circuit 23 for connection secured between a stand-by system of the latter device and a 0 system of the former device. The circuit 23 receives the signal 29 and sends a diagnostic start signal 35 to a diagnostic circuit 24. The circuit 24 sends a diagnostic input signal 31 to a diagnostic switching circuit 22 with the signal 35 and a diagnostic switch control signal 34 to a switching circuit 20. Then the circuit 24 compares a diagnostic output signal 33 returned from the circuit 22 with the signal 31 transmitted previously. The difference of both signals 33 and 31 is confirmed by the circuit 22, and all matrix switches of the circuit 22 are combined. Furthermore the circuit 24 sends a diagnostic end report 36 to the circuit 23 when all diagnostic operations are over. |
