Research Of Experiments Platform Of Networked Control Systems Based On PLC

In the21st century, network control technology has become the mainstream with therapid development of computer and network technology. And with a variety of controllertechnology matures, it makes the industrial network control possibly. Therefore, it needs toincrease the teaching content of network control of PLC in the campus.Three-tank water level control system is a big inertia, lagged behind, nonlinear time-varying and complex systems. Using conventional control algorithm, the system of controlaccuracy and robustness are very poor, especially the control requirements of unknownmodel and slow time-varying system which could not be satisfied.In this paper, distributed control network platform is designed based on Siemens PLCthat three-tank system as the control object for the current status quo. An adaptive fuzzyPID controller has been designed which has been simulated and verified by SIMULINK.Meanwhile, the algorithm and the program implemented in the PLC by the method oflook-up table addressed by the pointer.In this paper, using Siemens CPU314-2DP as main controller, using SiemensCPU224XP as slavery controller, using MICROMASTER440converter and pump asactuator, and sensor for water level complete the hardware design of the control system.RMON layer, field bus layer and field control layer have been used to build the threenetwork environment. The network configuration and hardware configuration of thecontrol system have been completed by using the software STEP7. The monitoringpictures of the control system have been designed by the software WinCC and WinCCFlexible for remote operator station.Finally, the relevant experiments have been completed on the build system platform.The results show that the fuzzy PID control algorithm and its improved algorithm forcomplex nonlinear system can be effectively controlled, and has fast convergence, goodanti-jamming, robustness and strong features, better than the general PID control methods.