PLC-BASED LEVEL CONTROL SYSTEM

Huidong Zhang, Jianhua Qin

ABSTRACT: In this paper, Siemens S7-300PLC is adopted to receive the data of liquid level sensor through the AD module. The control parameters of the collected liquid level are processed and the mathematical model is converted and the instructions are sent to the PLC. PLC adopts the PID control method, set and self-determined by the parameters of PID control.，eliminates the control process of static poor, the control parameter reaches a given value so as to realize the precise control of the liquid level closed loop regulation. Then the WINCC configuration software is used to design the human interface to connect the configuration to the PLC, and to reflect the real-time change of the fluid in the field in real time.

Keywords: PLC, Man-machine interface, Liquid level control, PID control