摘  要：介绍了步进电动机升降速的控制方法，提出了符合实际情况的S形升降速控制规律，阐述了控制系统的主要硬件及升降速过程的软件实现。该系统已成功用于某棉纺加工厂的送经装置，取得较好的效果。
关键词：PLC；步进电动机；S形曲线

Abstract: Introduced methods of step motor acceleration-deceleration.Put forward the S acceleration curve.Set forth the main hardware and software of acceleration-deceleration.This method of speed control has successfully applied on the transportation motor of the weaving factory.
Key Words: PLC;Step motor;S curve