Abstract
PLC programmable controller: PLC English full title Programmable Logic Controller, Chinese full title as the programmable logical controller, the definition is: One kind of digital operation operation's electronic system, for designs specially in the industry environment application. It uses a kind of programmable memory, uses in its internally stored program, the actuating logic operation, the sequential control, fixed time, counting and arithmetic operation and so on face user's instruction, and through digital either simulation type input/output control each type machinery or production process. PLC is based on the electronic accounting machine, and is suitable for the industry field work electric controller. It stems from following the electricity control device, but it does not look like following the electricity installs such, realizes the control through electric circuit's physical process, but mainly saves depending on the movement in the PLC memory the procedure, carries on into the information conversion to realize the control. Enters the information conversion, the reliable physics to realize, may say that is PLC realizes the control two essential points. Enters the information conversion to save depending on the movement in the PLC memory the procedure realizes. The PLC procedure both has the Manufacturer system program (not to be possible change), and has the application which the user develops voluntarily (user) the procedure. The system program provides the movement platform, simultaneously, but is also the PLC procedure reliability service and the signal and the information transformation carries on essential public processing. The user program according to controls the request design by the user. What control request, should have what user program.
Key words: programmable logic controller (PLC); industrial washing machine; Control
