| 摘要 |
PURPOSE:To decrease the connection defects due to the contact defects of a relay when one of those input data given from plural host devices is selected by the relay and sent to the follower devices. CONSTITUTION:A switch control circuit 2 receives a switch instruction signal from a host device and outputs a switch control signal. A switch repeating circuit 3 receives the switch control signal from the circuit 2 and switches a relay of a switch circuit 1 by the prescribed times. In such a constitution, the relay is actuated by several times by the circuit 3 with reception of the switch control signal. Then the contact state of the relay is monitored and an alarm signal is transmitted from the circuit 3 if at least one contact defect is detected. At the same time, the final contact state of the relay is detected and the result of this detection is outputted to the circuit 2 as a switch state signal. Then the detection result is outputted to the host device via the circuit 2. |
