摘要 ,对升降旗的控制要求也越来越高,使得越来越多的控制部分需要可编程控制器来实现. 本文结合任务设计书的要求,以自动控制为研究对象,采用了S7-,,,并真正地达到了实时控制的要求. 关键词:PLC 升降旗自动控制 Abstract Automatic control down the flag in the original traditional manual control innovation on the basis of a new type of product. With the development of PLC in China, to lift the flag of the control requirements have e more sophisticated , making more control of the programmable controller to realize some of the needs. In this paper, the design of the receipt of the task to automatically control for the study, using the S7-300 Series PLC controller for automatic control. In this paper, the design of the receipt of the task to automatically control for the study, using the S7-300 Series PLC controller for automatic control. The automatic control system of lifting the overall function of the flag were discussed, elaborated on position of the programmable controller and work. proposed automatic control of ponents of hardware modules and the detailed design of hardware modules, and control procedures for the design and programming. This design improves the quality control of the flag down and really achieve the real-time control requirements Key word: PLC, lifting the flag, automatic control 第一章绪论 4 4 4 8 自动控制分类方法 8 9 9 恒值控制系统 9 9 第二章方案确定 10 10 10 10 10 10 11 11 第三章 PLC控制系统总设计 12 PLC控制升降旗系统的设计 12 13 14 15 15 16 17 第四章电路的保护环节 18 第五章电气元件的选择及参数计算 20 第六章元件明细表 23 总结 24 致谢 25 附录一 26 附录二 27 附录三 28 参考文献 29 第一章绪论