Definition of the PLC

There are many definitions PLC. International Electrotechnical Commission (IEC) is the definition of the PLC: Programmable Logic Controller is a digital electronic computing operating plc programmable intelligent controller system, designed for applications in industrial environments. It uses a programmable memory, used in its internal storage to perform logical, sequential control, timing, counting and arithmetic operations such as operating instructions, and through digital and analog inputs and outputs, control types machinery or production processes. Programmable logic controller and related equipment, all with industrial control systems should be easy to form a whole, to expand the principles of the design of its functions. The mid-1980s to the 1990s, is the fastest growing PLC period, the annual growth rate has been maintained at 30 to 40 percent. During this plc analog input output io module period, PLC capability in handling analog and digital computing power, man-machine interface capabilities and network capabilities have been greatly improved, PLC gradually entering the field of process control, in some applications in the field of process control to replace the dominant DCS systems. PLC has the versatility, ease of use, wide adaptation, can be * high anti-jamming capability, programming and simple. PLC in the industrial automation and control especially in order to control the position, in the foreseeable future, can not be replaced.