超小型PLC数字逻辑程序设计方法的应用

Application of Digital Logic Program Designing Method of Microminiature PLC

介绍超小型可编程控制器 (PLC)在循环冷却水系统应用中数字逻辑的程序设计方法。用安装于水池下部的压力传感器间接检测出水位信号 ,将此连续变化的水位信号通过施密特触发器变换为高水位和低水位信号(高低电平 ) ,然后送到PLC系统去控制水泵的运转。通过对回水阀和补水阀的控制 ,可实现对水温的调节。

To introduce digital logic program designing method of microminiature PLC application to circular cooling water system. Water level signals can be examined indirectly by pressure sensor installed on the bottom of pool. Water level signals varying continuously are transformed into high water level and low water level signals (high and low electrical level) by Schmitt trigger, which are transmitted to PLC system so as to control the operation of water pump. Temperature of water can be adjusted by controlling backwater valve and supply valve.