Learning electronics people know, PLC is a very important device, but also relatively difficult a technology, it is designed specifically for applications in industrial environments and the design of the digital computing operation of electronic systems, is to achieve industrial automation, the Internet of Things control basis, the future has a very broad application prospects.
PLC technology originated in the United States, the first PLC applications is the United States General Motors, the 1960s, they are adjusting the factory production line, found that the relay, contactor control system modification is difficult, large, noisy, inconvenient maintenance and poor reliability. Subsequently, the U.S. digital equipment company developed the first programmable controller, in the General Motors production line to try the effect is remarkable. After the PLC technology in Japan, Europe, Japan, Germany and other successful development of programmable controllers, in 1974, China also began to study programmable controllers, and widely used in major fields.
PLC was first to replace the mechanical switching device, and then the function of PLC gradually replaced the relay control board, modern PLC has more functions, its use from a single process control extends to the control and monitoring of the entire manufacturing system.
With the current point of view, PLC technology is widely used in various industries such as industrial automation, automotive electronics, transportation, Internet of Things control, etc. Its role in these areas can be broadly divided into four main categories.
PLC controller is a microprocessor with digital electronic equipment, digital logic controller for automation control, control instructions can be loaded at any time in the memory storage and execution, programmable controller by the internal CPU, instructions and information memory, input and output units, power modules, digital analog units modular combination of PLC controllers can be used for circumferential motion or linear motion control. Today's major PLC controller products almost all have motion control functions, which are used in a variety of machinery, machine tools, robots, elevators and other occasions.
From the configuration of the control mechanism, early directly for the switching I / O module connected to the position sensor and actuator, and now generally use a dedicated motion control module, such as stepper motors or servo motors can be driven to drive a single-axis or multi-axis position control module.
As an industrial control computer, PLC controllers can program a variety of control algorithms to complete the closed-loop control, in the industrial process control, PLC is mainly on the temperature, pressure, flow and other analog parameters such as closed-loop control. Large and medium-sized PLC have PID module, PID regulation is generally used in closed-loop control system with more regulation, many small PLC controllers also have this function module.
Modern PLC controllers have mathematical operations, data transfer conversion and other functions, can complete the data acquisition, analysis and processing; these data can be stored in the memory with the reference value comparison, to complete certain control operations, but also can be transmitted to other intelligent devices using the communication function. In large-scale control systems, such as unmanned flexible manufacturing systems, the PLC controller is one of the core components.
The Industrial Internet of Things (IoT) is a major trend, and the technologies related to PLC communication and IoT will be highly popular in the future. The usual PLC controller communication contains communication between PLC controllers and communication between PLC controllers and other intelligent devices. With the development of industrial automation, the PLC controller manufacturers are very important to the PLC controller communication function, have launched their own network system, the new PLC controller has a communication interface, communication is very convenient.
The three main features of the future of PLC technology: 1, miniaturization, integration is getting higher and higher: with the market requirements for micro, integration, PLC technology is more integrated into the industrial, automotive, communications and other products.PLC products are characterized by control and data processing, in order to meet the functionality at the same time, the requirements of the process has become more refined. 2, intelligent PLC technology: with the development of AI technology, more Products are endowed with intelligent functions, PLC is no exception. Such as the application of PLC in the industrial control of intelligent I / O modules and automotive intelligent temperature control module, etc., the future of intelligent PLC technology will have more application scenarios.3, diverse PLC technology: which includes PLC-related programming languages and tools, with the depth of the application scenarios, one or more programming language is not able to achieve all the functions, customized PLC products will increase, PLC Modular technology will also increase.