A Programmable Logic Controller (PLC) is a widely used automation device in industrial control systems. It is a digital electrical device that achieves monitoring and management of industrial processes through programmed control. PLCs are extensively employed in manufacturing, energy, and various other automation fields. The foreign literature document titled 'Programmable-Logic-Controller-PLC.doc' provides detailed information and technical specifications about PLCs. Through the study of this literature, we can gain in-depth insights into the working principles, application areas, and technical features of PLCs. Additionally, we offer a Chinese translation of the document to facilitate the broader dissemination of knowledge in this field. By delving into foreign literature, we can not only understand the international application status of PLCs but also draw on advanced technologies and experiences to propel the development of the automation industry in our country.