Basic knowledge of electrical control, including relays, contactors, switches, asynchronous motors, etc. ; Fundamentals of digital circuits, binary, switching circuits, etc. Any PLC, Mitsubishi or Siemens. Buy a book, download the software with simulation, and follow the instructions in the book, and you will get it slowly. You must learn the basics. It is used for programming. Of course, you don't have to have a deep understanding of the basics, at least you have to understand.