摘要：PLC是一个以微处理器为核心的数字运算操作的电子系统装置，专为在工业现场应用而设计。文章通过介绍城市污水处理工艺流程和按PLC的污水处理实施案例，进行了基于PLC技术的城市污水处理系统的设计。文章包括硬件设计和软件设计两个方面，硬件设计采用PLC控制及差压仪表，不仅保证了滤水工序的性能指标同时解决了滤水器堵塞的问题；软件设计解决了1号机组及2号机组的反洗竞争问题，使用了互锁及延时的措施，保证了系统的可靠性运行，同时给出输出诊断程序以及判断执行器是否正常工作。最后通过系统调试，验证了系统的可行性。

毕业论文关键词：污水处理，PLC，硬件选择，软件设计

Abstract: PLC is a microprocessor as the core of digital operation electronic system device, designed for industrial field application in the design. The introduction of urban sewage treatment process and according to the PLC sewage treatment implementation case, based on PLC technology in urban sewage treatment system design. In this paper consists of two aspects: hardware design and software design, the hardware design of the PLC control and differential pressure instruments, not only to ensure that the performance index of water filtering process is also solved the water filter plug; software design solves the backwashing competition Unit No. 1 and No. 2 units, the use of the interlocking and delay measures, to ensure the reliability of the system operation, also gives output diagnostic procedures and to identify the execution device is working properly. Finally through the system debugging, to verify the feasibility of the system.

Keywords: wastewater treatment, PLC, hardware configuration, software design

目  录

1  绪论 4

1.1  课题背景 4

1.2  PLC介绍 5

2  污水净化处理系统设计方案 6

2.1  系统整体设计 6

2.2  污水净处理系统选择 7

2.3  系统的设计要求 9

2.4  系统工作流程 9

3  系统硬件设计 10

3.1  可编程控制器 10

3.2  系统硬件设计 11

3.3  硬件设计电路 12

4  系统软件设计 13

4.1  系统软件选用 13

4.2  系统软件设计 13

4.3  系统I/O分配表 14

4.4  污水处理中PLC的程序梯形图设计 14

4.5  故障诊断子程序的作用与设计 23

4.6  软件设计的可行性 26

5  系统仿真 26

5.1  S7-200与Profibus通信 26

5.2  系统调试 27

5.3  系统可行性阐述 28

结论 29

参考文献 30

致谢 31

1  绪论

1.1  课题背景