There are three commonly used programming methods: empirical method, the analytical method and the graphical method
1. Empirical method
The so-called “experience“ programming is the use of one‘s own or others ‘ experience. This method requires the user to be familiar with basic circuit conditions, grasp the basic principles of design of ladder diagram and programming skills in order to “experience program“ adapted for the requirements of their program.
2. Analytical method
PLC logic control, but the actual logic of the consolidated, therefore, be based on combinational or sequential logic theory, and applies appropriate analytical methods and logic to solve for it. Then, depending on the results, or draw a ladder diagram, or direct written instruction, analysis more closely, can be applied to certain standards, program optimization, and can avoid blindness in programming, is a more effective way.
3. Graphic method
Method of PLC programming method is by drawing the figure. Graphics can be divided into waveform diagram and flow chart. Waveform figure method more for Yu time control circuit, it first put corresponds to signal of waveform painting out, again according to time with logic relationship to combination, on can is easy put circuit design out; flowchart method is with diagram said PLC program of implementation process, and entered conditions and output between of relationship, in using step into instruction of situation Xia, with it for design is is convenient of.
Graphic and analytic method cannot be completely separated, analytical method to drawing and graphic method to resolve column formula, but each have their own focus.