With the rapid development of microprocessors, computers and digital communication technologies, computer control has been widely used in almost all industrial fields. Modern society requires a quick reaction to the market requirements, manufacturing production of small batch, many varieties, many specifications, low cost and high quality products, in order to meet this requirement, production equipment and automatic production line control system must have high reliability and flexibility, programmable controller is comply with this requirement, it is based on microprocessor general industrial control device.

The Escalator is started by the relay escalator system. The relay system is composed of contactor, relay and travel switch. After a certain development in 1969, the United States first successfully developed the first PLC digital equipment company, escalator began PLC control stage, in the 20th century the development of micro-electronics, MCU, people began to the single-chip microcomputer control era of escalator.

There are a lot of logical signals to be processed in escalator control, which is done by PLC. Only by processing a large number of logical signals and conducting proper command of the relevant components, can the automation be completed overall control of escalators.

Escalator manufacturer According to the needs of the escalator running, PLC mainly run, stop, lubrication, maintenance, reverse the judgment, the safety circuit Fault judgment, speed deviation judgment and fault record, status display, etc. So-called fault processing function refers to the escalator safety circuit, escalator reversal, overspeed, failure, will automatically stop and alarm, prompt professional Maintenance Personnel maintenance, escalator before fault recovering unable to start. When the escalator, the upper hand strap inward and outward switch action, PLC in signal processing, disconnect the output signal of main contactor, L line contactor and contactor coil power, escalator stops, the buzzer ringing for a while at the same time, the malfunction indicator shows the corresponding code, which prompt maintenance personnel stop-upper hand strap inward and outward switch is the cause of action. At the same time, the fault code transmitted to monitoring and control system, so that maintenance personnel can in the shortest possible time arrived at the scene and accurate troubleshooting, make escalator running as quickly as possible.