At present our country has stepped into the era of automation. Whether it is an automatic soldering machine or an automatic screw-driving machine, PLC human-machine interface control is used in automatic control. This can better improve the production efficiency, increase the output, shorten the delivery time and get more profit for the company!

PLC programming is the key to the application of PLC automatic screwdriver. Programming language has instruction table, ladder diagram, sequence control can diagram, function block diagram and so on. Among them, ladder diagram is more intuitive, and it is a more common language for technicians who have some experience in relay interceptor application.

The methods and techniques of PLC programming of automatic screwdriving machine are empirical method, conversion method and logic method. Empirical method is based on some typical circuits, according to the specific requirements of the control system on the automatic screw-driving machine, after many iterations of debugging, modification and refinement, and finally get a more satisfactory ladder diagram.

With the empirical method of designing ladder diagrams, you can refer to some of the basic links of the ladder diagram and some of the past programming experience. Conversion method is to convert the relay circuit diagram into a PLC ladder diagram with the same function. The original relay control system has been proven to be able to fulfill the control functions required by the automatic screwdriver after a long period of use and test. There are many similarities between relay circuit diagrams and PLC ladder diagrams.

Therefore, the PLC ladder diagram is designed based on the relay circuit diagram. Logic method is the application of logic algebra to design programs in the method and form of logical combinations. Its theoretical basis is the logic function, the logic function is a logical combination of logic AND-OR-INVERT. Therefore, in essence, the PLC ladder program is a logical combination of AND-OR-INVERT. It can also be expressed in terms of logical function expressions, and automatic screw-driving machines also have to utilize these methods.