Design And Research Of Remote Teaching Experiment Of Process Control System Based On Internet

At present,in order to complete the teaching task of process control experiment,teachers in our school need to conduct on-site teaching to students.However,in some special cases,teachers or students cannot get to the laboratory,which increases the difficulty of the experimental teaching task.In order to solve this problem,according to the existing laboratory equipment such as PLC,DCS and water tank system,this paper proposes a method of remote control of water tank system liquid level by PLC based on Internet.Because the DCS and water tank system in this laboratory are connected by the way of field bus,so the PLC needs to establish a wireless connection with DCS before it can remotely control the liquid level of water tank system.The method proposed in this paper can support students or teachers to use PLC to remote control the liquid level of the water tank system in the laboratory outside the laboratory,which provides technical support for the completion of the corresponding remote teaching experiment tasks.This paper focuses on solving the problem of remote wireless communication between PLC and DCS.Modbus protocol,TCP protocol and OPC protocol are used in the communication debugging process,and the combination of three communication protocols is finally realized between PLC and DCS wireless communication.The water tank system in this laboratory contains two types of controlled objects that can be studied,namely,a single-capacity water tank system and a double-capacity water tank system.In order to verify the feasibility of the above remote wireless communication method between PLC and DCS,and at the same time expand the research breadth of the subject on the PLC algorithm,this paper selects the single-capacity water tank system and the dual-capacity water tank system as the controlled objects,first of all It carries out system model identification,and then uses single-loop PI control and(DMC)dynamic matrix control to complete the Matlab simulation experiment of the single-tank water tank system level control and the PLC remote control single-tank water tank level experiment,using PID cascade control and DMC-PID control completed the Matlab simulation experiment of the level control of the dual-capacity water tank system and the PLC remote control of the level of the dual-capacity water tank.Finally,a comparative analysis of the control effects of each control algorithm was made.Through the implementation of various experiments,the feasibility and stability of the wireless communication method between PLC and DCS proposed in this paper are finally verified.In addition,the experimental results also show that DMC is better than PI control algorithm in the aspect of the liquid level control effect of Single-capacity water tank;In the aspect of the liquid level control effect of double capacity water tank,DMC-PID control algorithm is better than cascade PID control algorithm.