Application of Programmable Controller (PLC)

Currently, PLC has been widely applied at home and abroad in metallurgy, petroleum, chemicals, building materials, machinery manufacturing, electric power, automobile, light industry, environmental protection and cultural entertainment and other industries, with the continuous improvement PLC cost performance, its applications continue expand. From the application type, application plc IO module can be broadly summarized as follows:
1. logic control switch
Using PLC basic logic operations, timing, counting and other functions to implement logic control, can replace traditional relay control for stand-alone control, multi-cluster control, automatic production line control, such as: machine tools, injection molding machines, printing machinery, assembly lines , plating lines and elevator control. This is the most basic application PLC, PLC is the most widely used applications.
2. Motion Control
Most PLC has to drag a stepper motor or servo motor single or multi-axis position control module. This feature is widely used in a variety of mechanical equipment, such as machine tools, assembly machinery, robots and other motion control.
3. Process Control
Large and medium-sized plc cpu modules has multi-channel analog I / O modules and PID control functions, and some small-scale PLC also has analog input and output. So PLC enables analog control, and has PID control function PLC may constitute a closed-loop control for process control. This feature has been widely used in boilers, reactors, water, wine, and closed-loop position control and speed control and so on.
4. Data Processing
Modern PLC have math, data transfer, conversion, and table sorting and other functions, can collect, analyze and process the data, while the data via the communication interface is transmitted to other intelligent devices, such as computer numerical control (CNC ) device for processing.
The communication network
PLC communications, including communications, programmable logical controllers systems and general-purpose computer PLC and PLC, PLC and host computer, PLC and other intelligent devices can directly or through the communication processing unit, a conversion unit connected to the communication network to achieve the exchange of information and may constitute "centralized management, decentralized control," the multi-level distributed control system to meet the needs of factory automation (FA) systems development.