【正文】 the logic operation ability, and can read the procedure save the contents of the machine to drive the homologous saving machine and I/Os to connect after pass the calculation。s fluctuation, forms the lift control system. PLC Introduction Programmable controller is the first in the late 1960s in the United States, then called Plc programmable logic controller (ProgrammableLogicController) is used to replace relays. For the implementation of the logical judgement, timing, sequence number, and other control functions. The concept is presented Plc General Motors Corporation. Plc and the basic design is the puter functional improvements, flexible, generic and other advantages and relay control system simple and easy to operate, such as the advantages of cheap prices bined controller hardware is standard and overall. According to the practical application of target software in order to control the content of the user procedures memory controller, the controller and connecting the accused convenient target. In the mid1970s, the Plc has been widely used as a central processing unit microprocessor, import export module and the external circuits are used, largescale integrated circuits even when the Plc is no longer the only logical (IC) judgement functions also have data processing, PID conditioning and data munications functions. International Electrotechnical Commission (IEC) standards promulgated programmable controller for programmable controller draft made the following definition : programmable controller is a digital electronic puters operating system, specifically for applications in the industrial design environment. It used programmable memory, used to implement logic in their internal storage operations, sequence control, timing, counting and arithmetic operations, such as operating instructions, and through digital and analog input and output, the control of various types of machinery or production processes. Programmable controller and related peripherals, and industrial control systems easily linked to form a whole, to expand its functional design. Programmable controller for the user, is a noncontact equipment, the procedures can be changed to change production processes. The programmable controller has bee a powerful tool for factory automation, widely popular replication. Programmable controller is useroriented industries dedicated control puter, with many distinctive features. First, high reliability, antiinterference capability。s many control domain from the blackwhite control system. Along with society39。 外文原文 PLC application in the development trend of the elevator Programmable Logic Controller (PLC) is a mon control device which use puter technology as a core, PLC gets a wide range of applications in all walks of life. In the elevator industry, PLC’s role has been fully expressed. This paper introduces the PLCcontrolled model of a fivestory elevator， include it’s position, main function, the I/O interface distribution of the PLC, the PLC’s programming methods and procedures design of the elevator system. With procedures design of the elevator control system can achieve the elevator door’s opening and closing control, and the elevater’s indication under the call, moving from top to bottom, startingup, delay closed, Ping layer, opening the door, making signals in the queue, close to the escalator and alarming control under the mode of the elevator’s operation mode. Through the process of piling software, hardware connection and the conjunction of elevator model and the PLC control system, which makes the elevator control system model intuitive reflected in the course of operation and realized the elevater’s functional control. The 21st century will develop multipurpose, fullfeatured tower building, ultrahigh speed elevator continue to bee the research direction. Traction type superfast elevator research continues to super capacity motor, high performance by the microprocessor, damping technology, new roller guide boots and security clamp, permanent mag synchronous motor, elevator car air pressure relief and noise suppression systems propulsion. Using the linear motor drive there is also a greater research space elevator. Future superfast elevator intimacy will have increased significantly. Elevator iWith economic development, the increasing number of highrise buildings, elevators have bee indispensable in daily life the vertical transport. Better meet user requirements, development of high security, high reliability, high efficiency, low energy consumption, ride fort of the elevator, the elevator is the domestic and foreign enterprises and research institutions the main control system which was developed to achieve these objectives, the most important ways. The rapid development of industrial automation technology for the elevator control system technology update provides the material base. Continue to be the mos