The system is made up of PLC, transducer, units of pumps and electromotors, pressure sensor, industrial control computer and console. The system is used a transducer to make four electromotors startingrunningan electromotors is partly circulated. To connect control computer with PLC and realize supervisal, a real time supervisal control software of water supply system is developed. The software has the function of data connection, communication, state control of facilities and datamanagement.
Key Words: Variable frequency speed-regulating; Constant pressure
water-supply ;PLC; PID
