The form adopted by the computer control system is closely related to the complexity of the production process it controls. Different controlled objects and different requirements should have different control schemes. According to the function and structural characteristics of the computer control system, the computer control system can be divided into:
(1) Operation guidance control system;
(2) Direct digital control system;
(3) Computer supervision and control system;
(4) Distributed control system;
(5) Fieldbus control system.
The linear digital control system is the most common way for computers to be used in industrial processes. It belongs to the closed-loop control structure. It uses a microcomputer to patrol multiple controlled parameters. The test results are compared with the set values. The PID (proportional, integral, derivative) law or direct digital control method performs control operations, and then outputs to the actuator to control the production process, so that the controlled parameters are stabilized at a given value.  That is to say, the computer patrols the parameters of one or more production processes by measuring components, inputs the computer through the process input channel, and performs calculation according to the specified control law and set value, and then sends a control signal to pass The process output channel controls the actuator so that each controlled quantity reaches a predetermined requirement.