With the arrival of the era of “machine replacement” and “industry 4.0”, industrial automation system has been basically realized in enterprises nowadays. Programmable Logic Controller (PLC) is the most commonly used control device in industrial automation system. It has been widely used in steel, printing and dyeing, chemical industry, paper making and mechanical processing and other fields. As the core course of automation specialty, the teaching of PLC must adapt to the actual needs of enterprises and society and carry out targeted teaching. A series of improvements and improvements have been made in terms of teaching objectives, teaching contents and teaching methods. Students majoring in automation need to have the ability to design, transform and optimize production control systems in enterprises by using control theory and technology, computer control technology and electronic technology.
Programmable Logic Controller (PLC) is a high-tech industrial control device with microprocessor as its core, which combines automatic control technology, computer technology and communication technology. It has the advantages of simple structure, easy programming and high stability.
It has been widely used in industrial automation control. After several years of construction and practice, the course “Principles and Applications of Programmable Logic Controller” strives to meet the needs of enterprises in terms of curriculum system, teaching content and teaching methods. According to the mode of combining theory with practice, we should pay attention to practice so as to cultivate students’engineering practice and innovation ability, so that students can adapt to the needs of enterprise production as soon as possible after graduation and go to suitable jobs. “Principle and Application of Programmable Logic Controller” is the core course of automation specialty.
Its knowledge covers such courses as “Automatic Control Theory”, “Process Control Instrument”, “Motor and Drive Basis”, “Power Electronics Technology”, “Detection Technology”, “Communication Principle” and so on. It has strong systematicness and practicality. After learning this course well, the students will design and develop the production control system of the enterprise, which can set up the following points of view. The concept of a production control system is a complete system, with signal input, signal processing, signal output and other links. PLC processes these input and output signals and controls them logically. Only when the system is well considered can it meet the actual needs.
The course is helpful to cultivate students’ability of system integration and comprehensive application. The development concept of PLC has undergone several generations of updates, from the foreign market to the domestic market, has been upgrading.
With the development of science and technology and the times, our teaching should constantly update and learn knowledge so as to keep advancing and not be eliminated by the times. The purpose of learning engineering concept course is how to apply PLC to practice. The “engineering design” method and some practical application examples in the course can guide students to think more in line with engineering practice, and thus help students to cultivate engineering concept. The establishment of these concepts paves the way for students to learn in the future and can cultivate a scientific way of thinking. This course is a specialized course of automation specialty. The course content is divided into two parts: classroom teaching and experiment.
However, in the process of teaching practice, it is found that students focus on theoretical learning, practice and design are relatively few, and the application of programmable logic controller is relatively vague. Through the study in university, although we have learned the principles of the relevant electrical components and the use of programmable logic controller, we still lack the ability of system design, so we can not design a practical system which can be used in enterprise production. Although there are some experimental lessons, many students do not understand the principle, do not know how the system in the experiment is designed, the experiment procedures are copied. The purpose of doing the experiment can not be achieved. The cognitive teaching content should be strengthened and students’understanding of common electrical components should be enhanced by combining physical teaching with graphic teaching. For example, in the teaching, the physical objects of programmable logic controller and switching components are displayed.
In this way, students will have a more perceptual understanding of the knowledge and things they have learned, which will help them to understand deeper knowledge. Increase the design link, through the combination of classroom teaching and design homework, improve the students’ability of system design, and adopt several design contents with more practical application, such as the forward and reverse integrated design of motor, the program design of speed measurement with encoder, the USS protocol communication between Siemens frequency converter and PLC, and the number of car roundtrips. The comprehensive design of a place and so on. By completing the design of these contents, students can have a complete concept of the design of a control system. Establish the concept of system. Based on the actual engineering, the relevant chapters of engineering design are added to explain how some systems are designed, developed and applied in practical engineering.
For example, a simple system, stamping system or rotating electrical testing system, which uses frequency converter, PLC and touch screen to control the speed of the motor. Through these examples, students will know where they can apply what they have learned. With the help of experimental platform, in-class experiments are set up, which require the design of hardware and software of the system to improve the students’system design ability. In-class experiment is also a small control system, to understand the whole system. Increase the content of curriculum design, improve the design and application ability of students’control system. Through a more comprehensive control system design to improve students’ability. Multimedia teaching is used in theory course. While teaching some principles, students can have an intuitive understanding of learning content by adding necessary demonstration animation. While teaching some devices, we should increase the cognitive physical teaching. For example, when explaining the structure of PLC, we should explain the power module, I/O module, CPU module, data memory and so on, so that students can have a clear impression of PLC. Then, relays, switches and so on can be explained in combination with physical objects. In this way, students will have a perceptual understanding and the teaching effect will be very good. When teaching specific engineering examples, we should introduce the application background, thermostatic element improve students’interest in learning and understand what occasions the knowledge can be applied. By arranging the design questions after class, the students are divided into groups to design.
Each group chooses a person in charge. After completion, each group will go to the platform to answer, so that the students’self-study ability and practical ability will be improved. Give praise and encouragement to some well-designed students to improve their enthusiasm. Before the experiment class, students are required to design the hardware and software of the system, so that students are familiar with the whole system of their experiments, and not limited to writing a few codes. Although sparrows are small, they have all five internal organs. If you can dissect sparrows, so will the rest. Finally, in the examination of PLC course, the results are composed of the usual results, final results, experimental results and so on. Usual results can be seen by the usual performance, homework, in-class testing and other components. The final grade is tested by a comprehensive examination paper. The experimental results mainly depend on the completion of some experiments, the completion of group design after class and the completion of curriculum design. Really outstanding assessment is a process, focusing on peacetime and practical ability to improve students’practical application ability. In classroom teaching, students’learning enthusiasm has been improved, their concentration has been strengthened, and their interaction with teachers has also been formed. Homework can also be done with high quality. In the experiment, the effect is improved obviously.
Before that, most of the students could only write a few pieces of code mechanically and complete simple functions. Through the reform, most of the students can design the whole system completely now, and the programming is flexible. They can use several different methods to achieve the same function.
There is a strong learning atmosphere, and problems that you don’t understand will be actively discussed with each other. In a word, through the teaching content and means to improve the teaching links, improve the quality of teaching, so that students can master the theoretical knowledge of the major skillfully, and through the practical teaching links to improve students’system design and application ability.