plc毕业设计说明书外文文献翻译 可编程控制器原理及其应用.doc

2012届毕业设计说明书 外文文献翻译 院 、 部： 电气与信息工程学院 学生姓名： 指导教师： 职称 副教授 专 业： 班 级： 完成时间： PLC Theory And Applications A programmable logic controller, PLC, or programmable controller is a small computer used for automation of real-world processes, such as control of machinery on factory assembly lines. The PLC usually uses a microprocessor. The program can often control complex sequencing and is written by skilled engineers. The program is stored in battery-backed memory and/or EEPROMS. Definition is: a digital electronic computer operating system specifically designed for using in the industrial environment. It adopts a category programmable memory for its internal storage procedures, the implementation of the logical operations, sequence control, timing, counting and arithmetic operations such as user-oriented instructions, and through digital or analog input / output control various types of machinery or production processes. 1 PLC Development Course In industrial production processes, a large number of switches in order to control it in a logical sequence of moves conditions, and in accordance with the logic of relations chain protection movement’s control, and a large number of discrete volume data collection. Traditionally, these functions are achieved through pneumatic or electrical control system. 1968 U.S. GM (General Motors) company replaced following electrical control devices, the second year, the U.S. company has developed a number of integrated circuits and electronic technology-based control devices, the first use of the means of the procedures applied to the electrical control, and this is the first generation programmable controller said Programmable Controller (PC) The functionality of the PLC has evolved over the years to include typical relay control, sophisticated motion control, process control, distributed control systems and complex networking. Personal computer (PC for short) has bee