PLC技术在电梯运行中的应用

采用德国西门子S7-200系列可编程控制器CPU226CN作为控制核心，扩充一个扩展模块EM223CN，以西门子MM440CN变频器作为电机拖动驱动，通过曳引机方式输出，实现了电梯的自动控制。电梯的主要功能有：响应内外呼梯信号，自动开关门，自动平层，自动显示轿厢位置（楼层）等。采用了全新的设计理念和思路，在技术上有重要突破，即将多个输入信号通过一个或门输入到PLC的输入端，通过PLC的内部逻辑运算单元将信号从中再筛选出来，节约了I／O口，从而大大地降低了硬件的设计成本。电梯具有升降平稳、舒适，运行安全、可靠的特点。

Application of PLC Technology to Operation of Elevators

Germany Simens S7-200 series programmable controller CPU226CN was taken as the control center and EM223CN model was extended, with the an SIEMENS MicrMaster440 being motor＇s driver, which has realized elevator＇s automatic control. The design＇s functions were as the following： Responsing to the inside and outside ladders＇ signals request, autoswitching the gate, automaticing the floor level, displaying the position of the floor automatically, and so on. This design adopted a completely new way and theoretical conception, further more achieved an important breakthrough in technology, which meant that multisignals of input were transmitted to the input end of PLC through one or gate, then signals were sieved by logic computation unit built in the PLC, thus saved I/O and lowered the design cost of hardware to a large extent. This elevator rises or falls steadily and comfortably, which is safe and reliable when moving.