Design And Implementation Of Liquid Level Control System Based On PLC

In industrial production,liquid level control is the most widespread and one of the most common parameters.And the traditional variety of mechanical circuit control or artificial control highlights the disadvantages,such as the low,the slow speed,the low sensitivity,which is far from meeting the needs of contemporary industrial development.In this case,we introduce a new control components,programmable logic controller(programmable logic controller PLC),which is widely used in various fields of automation control device.It combines the traditional relay control technology,computer technology and communication technology within one framework,which results in strong control ability.The operation is convenient with high reliability,which is suitable for long-term continuous work and variable level control.This research uses Siemens S7-300 PLC as master station system,S7-200 PLC as the system from the station by modulling EM277 PROFIBUS-DP to complete the master controller S7-300 PLC and the communication between S7-200 PLC and the station.System design uses traditional PID control algorithm and adaptive fuzzy PID algorithm to achieve automatic control of liquid level variables under different conditions.In this paper,the design of piping system by the size of the switch of the electromagnetic valve,electric valve switch and closing degree to realize water patterns,patterns of water,drainage mixed mode.This research designs the platform for first-order single tank constant liquid level control system.By this platform,we can also achieve second-order,third-order and multi order,etc.The complex liquid level control system,can also add other extended function modules,to achieve a more convenient and intelligent control function.