Study And Development Of Computer Aided Programmable Controller Experiment Instruction System

Programmable Logic Controller (PLC) is a kind of widely used automatic control device. Doing experiments is a very important way to learn and master the technique , so a widely range of importance is attached to PLC's experimental teaching. The normal experiment way is to use a set of experimental devices , a main-machine and I/O devices , but this kind of devices cannot be satisfied in many schools, the main reasons are the limited application, shortage of money and so on. Therefore many students do not have enough opportunities to practice in person. Hence, the technology of 'Virtual Instrument' and 'Analog Simulation' are adopted to use software to simulate the set of equipment.This paper which faces the teaching of the course - "Programmable Controller's Principle and Application" takes the Mitsubishi main unit FX_on-40MR as the experimental machine, uses the basic principle of 'Virtual Instrument' and 'Analog Simulation', adopts the method of Object-Oriented Analysis and Design, the technique of UML modeling, and uses the Visual Basic 6. 0 programming language and the Access database to built the computer-aided PLC experiment system. This system solved the distinction between less of experimental devices and the need of teaching, saved much money. And also it enriches teaching method, assures the experiment effectives, eases teacher's burden of coaching and maintenance. At the same time enhances the students' activity and enthusiasm.This system has been tried out in Linyi Normal university , in the experiment teaching of specialty of Electrical Engineering and its automation 2003 ,and practiced safe reliability and performance well . This system which meets the need of experiment of basic instruction has reached the system goal and demand.The system has many characteristics listed below. It can completely replace the whole PLC experimental devices, and has the same function. It provides the FX-20P HPP (Handle Programming Panel) interface for users to input program, load program, process program and save or list program, and can change program into ladder diagram automatically. It provides a simulated FX_ON-40MR main unit interface, on which we can change input terminals state on it, and obtain output terminals state, as well as a timing diagram.