Basic course of PLC, preliminary design of PLC program, PLC programming technology, maintenance and operation of PLC and common technologies. The research of PLC is very technical, and the application field of PLC is more and more extensive. Therefore, learning PLC should start from the basic course, and then learn PLC programming, PLC programming technology, PLC maintenance and operation, common technology and other courses, so as to learn PLC better. PLC (programmable logic controller) is the abbreviation of programmable logic controller. It is a multifunctional digital circuit, mainly used in automatic control applications. It can process various input signals and make corresponding output control, thus realizing automatic control.