In electrical information specialty, “programmable controller” is a professional course with strong practicality and comprehensiveness. The teaching effect of this course will have a certain impact on the learning of other related courses, as well as on the employment and work of students after graduation.
Based on the analysis of the current situation of programmable controller teaching, this paper puts forward the application strategy of engineering teaching mode in the course of programmable controller teaching. Programmable Logic Controller (PLC) achieves the control effect through the computer processor. In order to achieve the goal of high quality, low cost, multi-specification and multi-variety of products in the fierce market environment, the manufacturing industry adopts PLC to improve the flexibility and reliability of production lines or production equipment. From the feedback of employers at this stage, most of the students will encounter the work related to programmable controller in their employment. However, there are some problems in the specific work, such as the lack of practical ability of the students and the inability to solve the problems in the work. Therefore, this paper proposes to introduce engineering projects into teaching to improve students’practical ability and teaching effect.
Before learning the course of programmable controller, we should learn such basic courses as “Microcomputer Principle”, “Motor and Drive”, “Analog and Digital Electronic Technology”, which lay a foundation for the study of PLC course and enable students to have the ability of designing related electrical control circuits. At the present stage, because the direction and curriculum of automation major are more, the task is more arduous, and the time for students to study is limited, many schools have unreasonable phenomena in the design of teaching plans. For example, the PLC course starts before the basic course or at the same time with some basic courses. Because the concept of PLC is built on the basis of electrical control circuit, and many schools do not offer relevant electrical control courses, resulting in students in learning PLC courses, often difficult to understand, learning difficulties encountered. At present, the choice of teaching methods in some schools is also unreasonable, too much theoretical teaching occupies most of the time, leaving very little time for practical teaching, so students’hands-on operation ability can not be exercised. In addition, due to the wide application and variety of PLC in industrial production, the programming methods of PLC are different. There are no suitable teaching materials and experimental devices in teaching. For teachers and students, there are some difficulties in teaching and learning. Because the students lack the practice of theory, we should add experimental courses and choose some engineering experiments to help them master the theoretical knowledge better and improve their practical operation ability. At this stage, many schools choose the experimental equipment is mainly the experimental equipment of the test box type.
PLC and related components are installed at the bottom of the box, and the relevant state is completed by the indicator light. When students carry out experiments, they only need to make simple connections and employ programs to complete the experimental tasks. This kind of experiment mode makes the control function of the PLC completely unclear to the students, and the experiment is only a matter of the laboratory, which is severely separated from the actual situation in the industrial field. In the daily students, the emphasis is on the exercise of programming, there is no overall understanding of specific projects. In order to solve these shortcomings, in the experimental course, we can not choose the equipment of the test box, we should choose some open experimental equipment. For example, the drawing of hardware circuit diagram, system selection and configuration, software development and joint debugging of software and hardware, etc. Teachers guide students to complete these experimental projects independently. Finally, the quality of students completed is checked to ensure the effect of the experiment and the safety of the equipment, and the problems existing in the experimental middle school are solved in time. To achieve the goal of experimental teaching. In the industrial field, the application of PLC is very extensive. In practice, it is usually associated with knowledge of electronics, electricians, computers, machinery and hydraulic transmission. Therefore, in the experiment content setting, we should consider comprehensively and make the experiment as close to the reality as possible. Because the control systems used in industry are more complex, the control requirements of different systems and different industries are also different. Therefore, thermostatic element in the process of choosing the experimental content, we should select representative items, such as start-up and pneumatic-hydraulic drive control, motor drive control, process control with closed loop, etc. The change of experimental content also requires the replacement of experimental equipment. For simple devices, students can make them, and complex devices can be purchased.
Class hours are arranged for the training courses to be held on weekends, 6-8 hours each time. First of all, teachers should inform students about the time of experiment, grouping, project content and related requirements more than three days in advance. The purpose is to give students enough time to find relevant information for preparation, so as to ensure the efficiency and quality of the experiment. Secondly, before the beginning of the experiment, the teacher first let the students discuss the system process, control scheme, control requirements and so on. The teacher guided the discussion of the students in order to cultivate students’innovative consciousness and thinking. Thirdly, the division of labor among the team members, such as software programming, circuit schematic drawing, input and output point allocation, wiring drawing, simulation and debugging, is handed to different students to complete, so that the team spirit among students is also exercised. Fourth, according to the wiring diagram and the principle diagram, connect the wires. At this time, the teacher should prompt the students, pay attention to the distinction between strong and weak electricity, prevent the damage of equipment caused by weak electricity system accessing strong electricity. After the wiring is completed, the circuit is checked. After the teacher checks again, the power supply is connected. Fifth, download software. In the process of debugging, if there are faults, let the students find and solve the faults themselves, and train the students’ability to analyze and solve problems. Finally, the experimental structure is checked and accepted, and the experimental report is written by the students. To implement the engineering teaching method in the course of programmable controller, we need to pay attention to the following problems: because a large number of circuits in the experiment are designed by students themselves, it is necessary to ensure the safety of students’personal safety and equipment in the experiment; because the experimental devices are open, it is difficult for students to contact at first, so teaching. Teachers should set up the experiment content reasonably from easy to difficult.
In the course of the experiment, students should be encouraged more to improve their self-confidence. In the experiment teaching, competition mechanism can be introduced into the experiment, so that the groups can compete, discuss the different plans put forward by different groups, and give affirmation and encouragement to the best plan; and increase the reality appropriately.
Proportion of practice teaching. Through the implementation of engineering teaching method, the teaching quality of PLC course has been improved, and the students’practical ability, practical ability and problem solving ability have been effectively improved.