| 摘要 |
<p>PURPOSE:To decrease the number of troubles of an automatic control system and to reduce the cost of facilities by switching selectively an object to be controlled and the input signal for each process stage or time. CONSTITUTION:A sensor 5 contains switches SL1-SL4, SS1 and SS2 which perform the prescribed ON/OFF actions according to the position of a float which moves up and down in response to a water level 2. A multiplexer 7 connects an IN-3 to an IN-A of a programmable controller 8 and an IN-2 to an IN-B respectively when an IN-4 is kept at H, i.e., both SS1 and SS2 are kept OFF. At the same time, the OUT-1 and OUT-2 are connected to the OUT-A and OUT-B respectively. Then the multiplexer 7 performs a switching action when either one of both switches SS1 and SS2 is ON to connect an IN-5, an IN-1, an OUT-3 and an OUT-4 to the IN-A, IN-B, OUT-A and OUT-B respectively. Such switching actions decreases the number of troubles and reduces the facility cost of an automatic control system.</p> |
