编制顺序功能图的技巧与三种实现方法

Techniques and Three Implement Methods for Programming Sequential Function Chart

在《机电设备电气控制系统安装与维护》的理实一体化课程开发中,学生很容易编制一般顺序控制系统的梯形图,但是顺序控制系统的结构变复杂时,自身调试非常不方便且绝大部分学生理不清内在的逻辑性而不能编制出梯形图,达不到机电设备的自动控制要求。针对上述问题,采用FX系列的PLC编程,结合复杂并行序列结构的顺序控制系统实例,首先详尽阐述了顺序功能图(SFC)的组成、动作过程和绘制顺序功能图的注意事项;然后在顺序功能图的基础上,依次使用SFC功能编程、"启保停电路"编程和置位复位指令编程三种方法对结构复杂的顺序控制系统进行编程,为理实一体化课程开发和提高高职院校教师教学水平提供一定的参考价值。

In the curriculum development process of theory and practice integration for the electrical control system installation and maintenance of electrical and mechanical equipment, students can easily program ladder of the general sequential control system, but most of them don＇t comprehend inherent logic of ladder and program meeting automatic control requirements of electrical and mechanical equipment because of complicated structure and inconvenient debugging ladder itself of sequential control system. According to the above mentioned problems, the composition,motion, techniques and points for programming attentions of the Sequential Function Chart（SFC） are discussed using FX series of PLC, through the sequential control system example of complex structure parallel sequence. Based on SFC,the SFC functional programming, start-holding-stop circuit programming and Set-reset instruction programming, three of theses implement methods are used in SFC. The instructive principle is certainly given for the curriculum development process of theory and practice integration and improved teaching level of the vocational college teachers.