The application technology of PLC (Programmable Logic Controller) has a good application value for improving the practical professional skills of the students majoring in maintenance electrics, helping them to learn theoretical knowledge and operational skills, and also increasing great advantages for their future employment.
Based on many years of practical teaching and the characteristics of advanced work class students, the author summarizes several innovative points with strong teaching effect in the teaching process. PLC training is a very important course for students of advanced engineering. It is not only a practical subject of advanced engineering appraisal, but also with the development of science and technology, more and more automatic production lines are applied to PLC control operating system. This requires students to have certain basic knowledge in school, so as to better lay the foundation for future employment. Pad. For a long time, we all have a headache about the students’thirst for knowledge in technical schools. Faced with the problems of weak foundation, inability to study quietly and poor practical ability of students, students in technical classes are more obvious. However, with the increase of age, these students will more or less compare their future graduation ways. Attach importance to. In addition, the course of PLC itself is a subject with strong logic, so the requirement for students is not only to listen to lectures and take notes obediently, but also to stimulate students’strong interest and think independently. Based on the above factors, at the beginning of teaching, we should base on stimulating students’interest in learning and building up students’ self-confidence. Select more persuasive cases to introduce into the classroom, such as inviting some excellent graduates to come back to school to show their opinions, talk about the specific application and importance of PLC in the workplace, and then tell students what kind of knowledge they should have in school to meet the actual job requirements, so that students understand the current situation. The employment situation is grim, if there is no skill, it is difficult to stand in society, so as to stimulate students’internal learning motivation. Using experiments as a reference for our teaching is in an integrated classroom.
Teachers make full use of the equipment conditions of the classroom. At the beginning of the lecture, they show students some simple experiments, such as walking lights, elevator control, traffic lights control, etc. At the same time, they show the graduation design made by the graduated students to the students. On the one hand, they can stimulate them.
Students’interest in learning, on the other hand, can also let students understand that as long as they do it carefully, they can make their own works, and enhance their self-confidence. With the help of the favorable resources of the school, we can provide a good platform for students to get out of the school and go to the automated production line of the actual factory, so that students can have face-to-face contact with the workers and technicians of the factory, so as to have a more intuitive understanding of the application of PLC in modern industry. “Flipping Classroom” is a new teaching mode introduced in recent years. This teaching mode has overturned the traditional teaching mode of “teachers teach in class and students finish their homework after class”, allowing students to watch videos at home to replace teachers’classroom instruction. In class, let students focus on completing exercises and interacting with teachers and peers. In the teaching of PLC practical training, giving full play to the advantages brought by this teaching mode not only greatly shortens the preparation time of practical training, but also allows students to deal with a specific knowledge point repeatedly, such as the teaching task of “three-phase asynchronous motor forward and backward control”. Before class, teachers record the whole training preparation and implementation process. Then, after introducing control requirements in the first lesson, let the students analyze the control requirements and complete the production of input and output allocation table. In this process, the middle school students take the group as the unit, give the students enough time to discuss and communicate, and then play the video to check whether the allocation is correct. The connection of PLC main line and control line is the difficulty of hardware part in the training, and also the safety problem that we pay special attention to. Teachers first play a teaching video about safety accident through video, which makes students pay more attention to it ideologically. At this stage, students are required to list the trial process in the form of posters. Some points for attention and preventive measures. Received good teaching results, in the subsequent teaching process also reflects the importance of standardized operation. The teaching method of flipping classroom requires that special attention should be paid to students’work and rest schedule in the course of teaching. Students have to work hard after class to achieve results with problems in class. Based on the characteristics of PLC course itself, its knowledge points are more specific. Each recording has a strong pertinence to a certain point and a certain experiment, so students can solve specific problems well.
The explanation of the training of “positive and negative control of three-phase asynchronous motor” is divided into several parts: input and output distribution table, wiring diagram, ladder diagram and sentence table. After watching the teaching video after class, students can clearly understand the knowledge points they want to learn, so that they can grasp the course content well. The first few chapters of the textbook in use explain the working principle of PLC. The proper working principle is the most difficult for students to understand, because they are all non-physical knowledge points. When dealing with this part of knowledge points, arrange for the later practice, so that students can understand thoroughly after a certain training project.
Only by arranging the order of teaching contents according to local conditions can we give full play to students’strengths and enhance their confidence, and let students overcome learning difficulties with courage, so as to enable students to understand knowledge from intuition to sensory depth. On the subject of “combined drilling machine” in PLC training, the knowledge points involved in the study of machine tool control circuit. How to let students understand the control principle in the process of practice and improve the level of quota, independent installation and maintenance operation is the teaching focus of this professional practice. It is impossible to solve the problem fundamentally only from the installation wiring of circuit board and the compilation of trapezoidal diagram, because the control circuit of a drilling machine is various, different control objects have different control circuits, and the programming methods and external wiring are different, of course, in the actual application of the original cause of the failure. Because there are many kinds. Therefore, only by using the control device to find out the fault points and determine or narrow the possible scope of the fault, can we quickly find out the fault points. In textbooks, it is only limited to the knowledge of electrical theory to understand the control principle. Through more practice, it is possible to find out the hardware and software part of the control. Full ground capacity for maintenance at fault points.
Based on the above reasons, the author first leads the students to understand the actual application of drilling machine, borrows the drilling machine equipment of school-enterprise cooperation to communicate with the teachers related to NC specialty, finds out the fault points related to circuit control through practice, and then summarizes and analyses that most of the control circuit problems lie in logical operation, through learning. Student’s summary, on-the-spot investigation, find out the key to the problem, and then proceed to the learning control theory. Facts have proved that students benefit a lot from it, and they are very interested in it, and they do not feel bored at all. In the whole process, students not only learn the logic circuit related to control, but also have practical experience and improve the ability to solve practical problems. The transformation of ladder diagram and sentence list in PLC training is also a headache. Students often can not understand the process of their work while learning.
Teachers also integrate this part of knowledge into the experimental equipment in the process of teaching, so that students can understand the logical process through their own hands, make full use of teaching experimental equipment and borrow different ones. The display panel adds more relevant examples for drilling, such as single motor starting, forward and backward, sequence control, and then adding similar actions of multiple motors, so that students can have a step-by-step learning process from simple to rare in the programming of PLC, and ultimately enable students to firmly apply various instructions and play well. A solid foundation.
The development of PLC technology in our country is relatively short, but in recent years its practicality has brought great impetus to our industrial level. It has been used in almost all walks of life, even in our daily life. It not only greatly improves the economic efficiency of enterprises, but also solves the difficulties in mechanical maintenance and the trivial regulation and control of procedures. The problem of breakage has brought convenience to our life. A direct example is the elevator used in shopping malls and properties, and the module part of traffic lights. Therefore, in the course of teaching, the author uses modular training to divide a training project into several modules, such as input and output allocation, wiring diagram drawing and control program writing. The knowledge points are refined and solved one by one, and the cultivation of students’analytical ability is emphasized. In addition, in the process of training, we should also pay attention to students’self-detection. After compiling a control program, we can simulate it by the school’s training equipment.
So different team members will have different design ideas, thermostatic element cultivate students’ communication and cooperation ability, and finally summarize, so that the design of mutual evaluation and exchange between groups can be carried out. Want to broaden the way of thinking, improve the thinking ability of students. Programmable controller technology itself is a highly theoretical, interesting and practical course. In order to cultivate technical talents suitable for the development of the times, teachers must grasp the basic training of professional teaching, fully adopt various teaching modes and ways, mobilize students’initiative and enthusiasm in learning, and make them learn. Students can maximize their thinking ability, hands-on operation ability and innovative ability to improve the efficiency of classroom teaching. Let our students out of the school door, to meet the requirements of the times.