Process control
Process control refers to the closed-loop control of temperature, pressure, flow and other analog quantities. As an industrial control computer, PLC controller can prepare a variety of control algorithms, complete the closed-loop control. PID adjustment is a common adjustment method in general closed-loop control system. Large and medium-sized PLC have PID module, many small PLC controller also has this function module. PID processing is generally run special PID subroutine. Process control is widely used in metallurgy, chemical industry, heat treatment, boiler control and so on.
Data processing
Modern PLC control has mathematical operations (including matrix operations, function operations, logical operations), data transmission, data conversion, sorting, table lookup, bit operation and other functions, can complete the data collection, analysis and processing. These data can be compared with the reference values stored in the memory to complete certain control operations. They can also be transmitted to other intelligent devices by means of communication functions, or they can be printed and tabulated. Data processing is generally used in large control systems, such as unmanned flexible manufacturing systems; Can also be used in process control systems, such as paper, metallurgy, food industry in some large control systems.