| 摘要 |
<p>PURPOSE: To detect and monitor a fault even when the operator is not aware of power supply voltage fluctuation even on the occurrence of the fluctuation in the power supply voltage of commercial power supply by detecting and displaying the voltage of the power supply supplied from an external device to a plant controller main body. CONSTITUTION: Upon the receipt of a commercial power supply 1, a power supply receiver 8 reads a power supply voltage at the entrance of a power supply device 3 for a plant controller controlling a plant. A data arithmetic unit 9 compares the read voltage with a preceding voltage to obtain a maximum value/minimum value/current value and to display the value on a data display device 10. In this arithmetic processing conducted usually, the data are updated into a newest value at all times. Thus, the operator immediately confirms power supply fluctuation width generated from the preceding time till now. Even the power supply voltage not appreciable for the operator is easily grasped and proper processing is conducted by detecting the power supply voltage at all times and monitoring it.</p> |
