1, you must master a certain electrician foundation: master the use of common devices such as sensors, proximity switches and encoders and the working principle of contactors.

2. Master basic computer knowledge: be familiar with the installation of various software and the setting of network communication.

3. Counter and timer should be assigned before use.

4. The expression of logic function diagram basically follows the logic language of "AND", "OR" and "NOT" gates of digital logic circuits, and is expressed in the form of logic block diagram.

5. Describe the program with logical function diagram, which is convenient to describe complex control functions, intuitive to express and easy to check errors.