PLC overview and application field

The company mainly produces AC contactor, mini circuit breaker, plastic enclosure circuit breaker, double power automatic switch, frame circuit breaker, vacuum circuit breaker and other products. Huatong takes everyone to understand the overview of PLC and the application field.

Introduction

Over the years, the programmable controller (hereinafter referred to as PLC) from its generation to the present, has realized the connection logic to the storage logic leap; Its function from weak to strong, realizing the progress of logical control to digital control; Its application field has grown from small to large, realizing the leap from simple control of single equipment to competent motion control, process control and distributed control and other tasks. Now PLC in the processing of analog, digital operation, human computer interface and network in all aspects of the ability has been greatly improved, become the mainstream control equipment in the field of industrial control, in all walks of life is playing a more and more important role.

The application field of PLC

At present, PLC has been widely used in iron and steel, petroleum, chemical industry, electric power, building materials, machinery manufacturing, automobile, textile, transportation, environmental protection and cultural entertainment and other industries, the use of the main categories are as follows:
1. Switch quantity logic control

Replace the traditional relay circuit, realize the logic control, sequence control, can be used for single equipment control, can also be used for multi-machine group control and automatic assembly line. Such as injection molding machine, printing machine, stapler machine, combination machine tool, grinding machine, packaging production line, electroplating line and so on.

2. Industrial process control

In the process of industrial production, there are some such as temperature, pressure, flow, liquid level and speed and other continuous changes (i.e., the amount of simulation), PLC uses the corresponding A/D and D/A conversion module and A variety of control algorithm program to deal with the amount of simulation, complete closed loop control. PID control is a kind of control method which is widely used in general closed loop control system. Process control is widely used in metallurgy, chemical industry, heat treatment, boiler control and other occasions.

3. Motion control

PLC can be used for the control of circular motion or linear motion. General use of special motion control module, such as can drive the stepper motor or servo motor single-axis or multi-axis position control module, widely used in a variety of machinery, machine tools, robots, elevators and other occasions.

4. The data processing

PLC has mathematical operation (including matrix operation, function operation, logical operation), data transmission, data conversion, sorting, table lookup, bit operation and other functions, can complete the data collection, analysis and processing. Data processing is commonly used in large control systems in such industries as paper, metallurgy and food.

5. Communication and Networking

PLC communication includes communication between PLC and communication between PLC and other intelligent equipment. With the development of factory automation network, PLC now has communication interface, communication is very convenient.