| 摘要 |
<p>PURPOSE:To monitor an objective device remotely and effectively without degrading the monitoring reliability of the device to be monitored by setting the attenuation amount of each device to be monitored so that the devices to be monitored discriminate the total attenuation amount when the attenuation amounts are added. CONSTITUTION:A monitor line 7 which connects stations 2-1-2-n to be monitored in a loop starts and ends at a monitor station 4. Monitor contacts of the stations 2-1-2-n to be monitored insert attenuators 9-1-9-n in the line only when section switches in their stations are opened. The receiver 11 of the monitor station 4, on the other hand, finds the variable amount Lv of attenuation from the total amount Lt and fixed amount Lf of attenuation and transmits it to a discriminating circuit 12, which discriminates a station whose section switch 3 is opened among the stations 2-1-2-n on the basis of the received variable amount Lv of attenuation.</p> |
