【摘要】 介绍了 SIMATIC S7系列 PL C硬件的特点和 STEP7软件的功能。利用西门子 S7系列 PL C中 CPU内置的 PID功能块 ,控制纸张加工机收卷电机和放卷电机的转速 ,在纸卷直径不断变化的情况下 ,能始终保持走纸速度及张力恒定。阐述了系统的结构 ,硬件设计及软件的设计思路 ,同时提供了先进的控制方案。介绍了利用超声波传感器检测纸卷直径的方法。更多还原

【Abstract】 The paper introduces the hardware′s characteristics of SIMATIC S7 series PLC an d t he function of STEP7 software. Using the PID functional block in the interior o f CPU in the SIMATIC S7 series PLC to control the speed of rewinder and unwinder motor, also the PID functional block can help to maintain the norma l paper running speed in the case of uninterrupted change of the paper roll diame ter. The paper has explained the system structure, the design of the hardware a nd the idea of software. The paper supply advanced plan at the same time. It a lso has introduced the method of using ultrasonic sensors to monitor the pap er roll diameter.更多还原