With the progress of science and technology and the continuous development of manufacturing industry, industrial automation has become an indispensable part of the modern production process. In this field, programmable logic controller (PLC) plays a pivotal role. This paper will elaborate on the meaning of industrial automation, the application of PLC in industrial automation, problems and future development trends.

　　Industrial automation refers to the production process, the use of mechanical, electronic, computer and other technical means, so that the production equipment can automatically complete the preset production activities. Through automation technology, enterprises can significantly improve production efficiency, reduce labor costs, improve product quality, thereby enhancing market competitiveness. At present, industrial automation technology is moving towards the direction of intelligence, networking and high precision.

　　PLC is a digital electronic device specially designed for the industrial automation field, which can process input signals and generate output signals according to the internal program, thus controlling the operation of the production equipment.The main advantages of PLC include high reliability, flexibility, easy programming and debugging. However, PLC also has limitations in some aspects, such as slow processing speed and insufficient support for complex mathematical operations.

　　Although PLC has a wide range of applications in the field of industrial automation, there are some problems. First of all, the communication ability of PLC needs to be improved. The current PLC mainly relies on serial communication for data transmission, which limits the speed and reliability of data transmission to a certain extent. Secondly, PLC's ability to process big data is weak, making it difficult to cope with the increasing amount of data. Finally, the energy efficiency of PLC has to be improved, especially in energy-intensive industries.

　　To address the above issues, we propose the following solutions: first, develop high-performance communication technologies to improve the communication speed and reliability of PLC; second, enhance the data processing capability of PLC through cloud computing, big data and other advanced technologies; finally, actively develop low-energy, environmentally friendly PLC products to meet the needs of green production.

　　Looking ahead, with the continuous development of industry 4.0 and Internet of Things and other technologies, industrial automation PLC will usher in new development opportunities. On the one hand, PLC will integrate with artificial intelligence, machine learning and other advanced technologies to achieve more intelligent control; on the other hand, PLC will leverage high-speed communication networks to achieve more efficient data transmission and processing. In addition, with the improvement of environmental awareness, low energy consumption, green PLC will also become the mainstream direction of future development.

　　To summarize, industrial automation PLC has an important role to play in improving production efficiency, reducing costs and improving product quality. However, in the face of communication, data processing and energy efficiency issues, we need to continuously improve and innovate to adapt to the latest trends in industrial automation. By integrating new technologies and optimizing product design, we believe that PLC will play a greater role in the future of industrial automation and make a greater contribution to promoting industrial progress and social development.