| 摘要 |
<p>PROBLEM TO BE SOLVED: To make the actual state of load equipment consistent to the detected state of a transmission unit by returning the state of the contact input of current load equipment as monitor data to the transmission unit in a return wait period once a transmit signal having address data matching its address is received. SOLUTION: The terminal device 7 for contact input has its address set to an address that the transmission unit 3 polls, and is used by being connected to the signal line 2 of a remote monitor and control system. Here, the terminal device 7 is cyclically accessed by the transmission unit 3 and each time the device 7 is accessed, the state of the voltageless contact S of the load equipment 6 is sent back as monitor data in the return wait period of the transmit signal; and the transmission unit 3 detects the state of the load equipment 6 from the monitor data. Consequently, even if the contact input from the load equipment changes in case of a break of power supply or power failure, the transmission unit can always accurately detect the actual state of the load equipment.</p> |
