Modern society, the elevator has become an indispensable transportation equipment. Existence of the lift of each high-rise buildings more accessible. Elevator control technology has gone through three major stages: stage of the relay control, computer control of stage, stage of fieldbus control. At present, the use of elevators designed programmable controller (PLC), flexible and functional changes in requirements, programming is simple, less failure, low noise. Easy maintenance, energy-saving labor, anti-jamming ability, and control box covers an area of less. When the crew entered the elevator, press the floor button, automatic elevator doors closed, the operation control system to carry out the following: In accordance with the location of car and crew in which the number of layers to determine the direction of car to ensure that when the car decelerating flat layer. The car stopped at the selected floor; At the same time, in accordance with the call floor, the way of parking, automatic door switch. Also in the car both inside and outside lights should be displayed and the direction of the lift a few floors. With the rapid economic development, micro-electronics technology, computer technology and automatic control technology has been the rapid development of AC frequency converter technology has entered a new era, and their use has become an increasingly widespread. Elevator is a modern high-rise building, the vertical transport, the design requirements for stability, security and high. The structure of the lift with the continuous development of urban construction, the increasing high-rise buildings, elevators in high-rise building as a vertical run of the transport and people's daily lives have been inextricably linked. Elevator is a mechanical, electrical integration products. Mechanical parts of its body is like, the electrical equivalent of one part of the nerves, the control part of the human brain. Part by controlling the various parts of scheduling, in close collaboration, so that reliable operation of elevators.
Key words programmable controller, Elevator control system,relay