In recent years, with the continuous development of electrical control technology, the application of PLC is also increasingly widespread. The high performance of PLC controller makes it have strong adaptability and reliability, and it is widely used in the field of automation control. At the same time, because the cost of PLC is low and its function is increasing, it has become the main control equipment in the electrical control system of industrial enterprises, which promotes the sustainable development of industrial economy. This paper mainly discusses the application of PLC technology in mechanical control devices.
Programmable Logic Controller (PLC) is a kind of controller which is based on computer microprocessor and combines the comprehensive application of computer application technology, communication technology and automation control technology to form a strong universal controller. There are more complex microprocessors in the internal system of PLC, but in the process of practical application, even those who do not know enough about the internal processor can realize the effective use of it. Therefore, PLC has a wide range of applications.
At the beginning of its application, as a substitute for relay contactor control system, it has been widely used.
With the gradual expansion of the scope of application, PLC is gradually applied to the electrical control system. With its powerful anti-interference ability and self-diagnosis functions, the reliability of the electrical control system has been greatly improved, and the common fault problems in relay contactors have been effectively controlled. Therefore, PLC is used in the electrical control collar. Domain has been widely praised. Small size and light weight. Generally, the volume of the PLC controller is small, thermostatic element the size of the bottom of the super-small PLC is less than 100mm, and the weight is less than 150g.
Its power consumption is only several watts. Because of its small size, it is easy to install, and is conducive to the realization of mechatronics. It has strong practicability. PLC can be used in electrical control systems of different scales. In addition to the basic logic processing functions, most of the PLCs have the ability of data operation.
In recent years, the functions of PLC are also increasing, and its practicability is also widespread in many fields such as temperature control, position control and so on. Strong anti-interference ability. PLC control system uses a large number of integrated circuit technology, which is advanced in the internal circuit and production process, so its anti-interference processing technology is stronger, and the system reliability is stronger than the general controller. In addition, PLC has a certain function of automatic detection of hardware failures.
When the hardware system fails, it can automatically send an alarm signal. Its maintenance is relatively simple, and the maintenance cost is low, so it has a wide range of applications. This control technology is the most basic and widely used content in PLC control technology. It replaces the traditional relay circuit and makes the logical control and sequential control achieve synchronous control. The switch logic control can not only be used for the control of single equipment, but also realize the control of automation pipeline such as production line and modular machine tool. In the industrial production process, there will be many unpredictable variables, such as temperature, speed and other analog quantities, which will have a certain impact on the actual activities of industrial production. With the application of PLC control technology, the analog quantity can be converted into digital mode, and the controller can control it effectively. The control system is mainly composed of a powerful central PLC solid system and several devices, and forms a central integrated computer control system. In this system, different equipments can form a unified processing program by central PLC through proper mode and operation sequence. It can be seen that this centralized control system has the characteristics of low cost and high operation efficiency compared with a single control system.
But it also has some drawbacks. If the program of one of the control objects needs to be changed, the whole control system of PLC needs to be stopped, leading to other control objects have to stop running. In this system, each control object in the PLC control system is processed separately, and each PLC controller can complete the control task through effective signal transmission to realize the chain reaction of the internal network, or the transmission signal is transmitted through the bus by the upper computer. In the distributed control system, the mechanical control method used is the control method of multiple mechanical production lines. The corresponding data are connected between different production lines. Different control objects have separate control by PLC.
If one of them needs to stop running, it will not affect other controllers. In recent years, with the continuous development of science and technology, PLC and process control can be effectively combined, so that the bottom control task can be better realized. Through the technology of PLC, the effective control of circular motion or linear motion can be realized. In the control system, the traditional control mode directly acts on sensors and actuators, while the new control system can be realized by motion control module. For example, for the multi-axis position control module and the use of driving stepper motor, PLC is also widely used in robots, machine tools and other control systems.
In the data processing of the PLC control system, it has the functions of data transmission, conversion and operation, and can effectively complete the data acquisition and analysis. These data are stored in the memory of the system, which has a certain reference value for the normal operation of the equipment, as a basis for data operation. Data in memory can be transmitted to intelligent devices through the communication function of PLC. At present, there are many large-scale control systems, such as process control, which can be printed into tables when needed.
PLC control system combines the most advanced theory and technology in the field of computer and electrical control, and is in the process of continuous improvement in the functional indicators. It has made a new improvement in the traditional concept of PLC control, making it play a greater role in the field of electrical control.