This paper briefly describes the application of programmable controller in the integration of theory and practice teaching, including the explanation and training of hardware knowledge, the explanation and training of software knowledge, and the basic conditions for realizing the integration of theory and practice teaching. Programmable Logic Controller is abbreviated as PLC (Programmable Logic Controller). Learning Programmable Logic Controller requires hardware links and software programming. Therefore, theoretical explanation in class is not enough, and practical training is necessary. If we combine the two, the effect will be better. Next, I will talk about my practical experience with the application of classroom teaching in recent years. The teaching contents of the hardware part of the programmable controller mainly include the introduction of the control panel of the programmable controller, the explanation of the internal structure of the programmable controller and the explanation of the working principle of the programmable controller. In the hardware part of the programmable controller, the main teaching contents that students need to master are the connection mode of input terminal, the connection mode of output terminal, the meaning of operation panel and status indication sign, etc. For the internal structure of the programmable controller and the working principle of the controller, it is necessary to have some basic knowledge of analog electronic technology and the working principle of the computer. If the explanation is carried out, the teaching content is quite extensive. Therefore, we only need to focus on the external terminal wiring mode, for the internal working principle, students need to be familiar with and understand. Take the input explanation as an example.
In the theoretical explanation, it is enough to explain clearly the input requirements of the input terminal, the input common terminal and the power input terminal of the programmable controller. For example, which inputs can be controlled by buttons and stroke switches, and which inputs can be controlled by proximity switches. After explaining the input requirements of the input terminal, we can use the physical projection method, the physical display method and the demonstration operation method to make the demonstration more straightforward, so as to explain the input requirements and wiring methods of the input terminal. Because the input terminal wiring is relatively simple, students can basically connect correctly after reading the teacher’s explanation and drill, but teachers can not carelessly. Students can be divided into several groups during the training, and check the wiring in the group and the interchange wiring in each group until most of the students master it. The output terminal connection can be trained using the same method and steps. Finally, thermostatic element the teacher should explain clearly the special requirements and allocation of input and output terminals. Programmable controller software part of the teaching content mainly refers to instruction introduction and how to use instructions for programming. Common programmable controller instructions include: basic instructions, step sequence control instructions and functional instructions. The most common instruction of programmable controller is basic instruction. Most electric drive control circuits can be completed with basic instruction. Such as: motor unidirectional, point-to-point and positive and reverse control. Therefore, basic instructions are the most basic and important instructions. But the control purpose of programmable controller is generally a small system in industrial production. For example: intersection traffic light control, transmission sub-inspection device control, so it is also necessary to skillfully use and master step-by-step sequence control instructions and functional instructions. The teaching of programmable controller course focuses on the skilled use of various instructions. When explaining the basic instructions, it can be divided into several small units, after which some unit exercises can be carried out. If you want to make it more interesting, you can connect the input end with button switch, etc. and the output end with a small light bulb for input and output demonstration or practice. After explaining some small units, when a simple small control system can be formed, the integrated application of basic instructions can be introduced. The steps of comprehensive application knowledge explanation are generally divided into: analysis of control requirements, allocation of input and output points of PLC, design of control program and debugging of control program. When explaining the analysis of control requirements, animation demonstration method can be used to increase intuition and interest.
How to realize the integration of theory and practice by explaining software knowledge, instead of tediously explaining one instruction and one instruction. This requires teachers to make full use of teaching resources, including teaching materials, projection equipment, computer teaching equipment and so on. In order to realize the integration of theory and practice in software knowledge teaching, it is suggested that the teaching course should be carried out in the training room, so that students can learn by doing and doing. General control system programming can not only be accomplished by one program, but also can sometimes be accomplished by several different programs. At this time, students will be given different procedures for analysis, by which students point out which program is better, good where, so that students can deepen the understanding of instructions and the basic requirements of programming. The control circuit of one-way continuous operation of a motor is designed by using PLC. The control circuit of a single motor needs two steps: starting and stopping. At the same time, self-locking function is required. Firstly, the hardware of PLC is designed. The main design of hardware is to allocate input and output points. Draw the PLC wiring diagram of the motor control system according to the input/output address table. Start control. Press SB1, X1 coil is powered on, X1 normally open contact is closed, Y0 coil is powered on, Y0 normally open contact is closed, KM coil is powered on, KM main contact is closed, motor is powered on to start operation, and Y0 auxiliary contact is closed and self-locking. Stop control. Press SB2, X2 coil to get electricity, X2 normally closed contact is disconnected, Y0 coil is disconnected, Y0 often open contact is disconnected, KM coil is disconnected, KM main contact is disconnected, motor stops running, and Y0 auxiliary contact is disconnected to release self-locking. Transfer the control program to the PLC, and then run the PLC for debugging. Program debugging is an important part of program design. Only after trial run can the control program be found unreasonable and modified.
Vocational education should train more students’practical ability and ability to solve practical problems. Therefore, we should subvert the existing teaching mode which attaches importance to theory and despises practice, and adopt the backward teaching mode. According to the application of programmable technology in industrial control, this paper analyses what practical problems and industrial standards students need to solve and what content they need to master. According to these contents, relevant knowledge points are determined to form a talent training program. According to the talent training program, we should select the appropriate teaching materials. If there is no integrated teaching materials, professional teachers and professional and technical personnel of enterprises should work together to compile them.
Develop a set of integrated teaching methods, professional training for teachers, to achieve the integration of teaching methods. To build a teaching site of integration of theory and practice to meet the requirements of the teaching environment of integration of theory and practice. Establish an assessment system, establish evaluation criteria, and make a real evaluation of students’abilities. In a word, the integrated teaching mode of rationality and reality is a systematic whole, and every link is indispensable. In order to truly realize the integration of theory and practice, all links need to cooperate with each other and accomplish together.