Abstract：In this thesis, the focus is the principle of frequency conversion constant pressure water supply control, designing frequency conversion constant pressure water supply control system. Using Panasonic PLC (FP0 - C32CT) and analog input / output modules (FP 0-A21). Pro-face Touch screen (GP37W2) and Fujitsu Inverter (FVR - E11S) constitutes a constant pressure control system for water. According to different water instantaneous pressure in different times ,the system could automatically adjust the pressure of water supply system, at the same time, the system has the function—regular automatic switch the pump motor when water consumption is in non-peak period.
In this design touch screen is used as man-machine interface, because Touch screen and PLC both are universal. Operating the touch screen could control various functions, while touch screen could real-time monitor current states of system .
Keyword: constant pressure water supply；PLC；touch screen; analog input/output module；transducer
