Remote Experiment System Of Comptuter Process Control Based On DDC

For the engineering students whose major is automation,it is very important to develop the professional application ability by using remote experiment system,and experimental teaching is a necessary part of the teaching procedure,the theory can be verified through practice for students.Meanwhile,problems can be solved effectively which are the decline of teaching quality and an increase of teachers' work intensity due to mismatch of students and experiments.Aiming at the above problems,resources of laboratory are used to solve it in the paper,on the basis of the original control mode,remote experiment system is added.CS4000 process control experimental device is taken as controlled object.DDC system is chosen as the local control mode.C/S architecture is adopted to implement applications of remote client and control server.The fourteen devices and network cameras are placed in a network to realize goals which are remote real-time control,data acquisition and real-time video preview.The main works of the paper are as follows:1.The local experiment system was upgraded,and the remote experiment system program based on DDC was designed.The real-time on communication program of system was taken an important part to analyze.Two serial communication method in Visual C++6.0 were used to communicate with the DDC module and test the real-time of serial port communication.A better way to transfer API function was chosen as serial communication method of system.Winsock based on the TCP/IP protocol was taken to program,network communication service program between client and server is implemented.And the relationship between real-time network communication and communication distance was test.Finally,by analyzing real-time performance of the system,and the scheme is feasible.2.Visual C++6.0 was used to develop the control server,among them,the serial communication was realized by asynchronous communication.Multi-threaded technology was adopted to realize the program of network communication,serial communication and data processing.ODBC components was used to achieve operation which is Visual C++ applications for the MySQL database.And then use the program to implement incremental PID algorithm.In the end,historical database table was designed and storage rules was defined to reduce the storage.Visual Studio 2012 was adopted to develop remote client applications.Remote client interface was designed and achieved by using MFC base class library.Curve drawing library CChart developed by teacher Yang(Yang Guojun)was applied to reach functions which are display of real-time data curve and query of historical data.So as to achieve real-time video preview,redeveloping application on the basis of the equipment network SDK.Finally,application layer protocol were designed and delimited.Multithread technology was utilized to implement part of the program which is remote client network communication.3.Network was composed and forwarding rules of router was installed in the system.Then aiming at main function of the system,to find out problems of the system and re-optimize it,an actual example was designed to test main function and experimental results of the system.