【摘要】 介绍了PROFIBUS现场总线过程控制系统组成和STEP7中的用户程序块。说明了S7-300 PLC中的编程模块。基于语句表STL进行了二阶双容水箱液位控制程序设计。阐述了手动与自动切换功能,可以实现无扰切换。给出了二阶双容水箱液位控制监视界面的显示图。描述了基于语句表STL的水箱液位串级控制程序设计。更多还原

【Abstract】 This paper introduces PROFIBUS field bus process control system and user program block in STEP7. Programming module of S7-300 PLC is illustrated. Two order double tank water level control program based on the statement list STL is designed. The switching function of manual and automatic is expounded. Bumpless switching can be realized. The two order double tank water level control and monitoring interface display graph is given. Cascade control programming design of the water level based on STL is described.更多还原