As an important means of transportation in high-rise buildings, elevators are more and more closely related to people's work and life. As a new generation of industrial controller, PLC is widely used in elevator control with its high reliability and advanced technology, which makes the elevator develop from the traditional relay control mode to the important direction of computer control and become one of the hot spots in elevator control and technical transformation.

PLC is a microcomputer system dedicated to logic control. Because PLC has the characteristics of stable performance, strong anti-interference ability and flexible design and configuration. So it has been widely used in industrial control. Since the introduction of PLC into China's elevator industry in the late 1980s, the elevator control system composed of PLC has been widely adopted by many elevator manufacturers. And formed a series of stereotyped products. In the reconstruction project of traditional relay system, PLC system has always been the mainstream control system.

Elevator control system is divided into speed regulation part and logic control part. The performance of the speed control part has an important influence on the operation of the elevator and the comfort of passengers, while the logic control part is the key to the safe and reliable operation of the elevator. In order to improve the comfort and reliability of the elevator, PLC is now used to control the operation of the elevator, which greatly improves the performance of the elevator.