The Application of Siemens S7-300 PLC to Control System of Process (Laboratory Tank Level)

This paper introduces the process control system (PID control system) which is realized by Siemens S7-300 PLC and WINCC. In the system hardware configuration, CPU315-2DP which integrates PROFINET interface is adoptde.PROFIBUS and industrial Ethernet are both come into consideration.and describe the hardware and STEP 7 which is used to programming.To introduced emphatically the application of the module SFB41 (function block).The parameter settings and programming of the SFB41 .In the same time ,it also desicribes the hardware configuration,software configuration,net connection,control function,the working process and the adjusting function of the liquid level’s variable frequency speed regulating PID control. S7-300 PLC control the MM440 inverter via the PROFIBUS-DP protocol.The good performance of control can be seen since its application and automatic ingredient control can be aslo realized, and the purpose of increasing the control level can be reached.The paper also introduces that how to use WinCC (Windows Control Center )to collect the data from different types based on OPC technology and database skills.In the parameter settings of hardware and WinCC,the alarm messages is described and discuss the main effect. The system can be realize the remote monitor, and also realize the data collect, record and print for the Manufacture Execute System.The data of the experiment is arrived the requirements of the control system.