system in sewage treatment, the reliability of automatic control has been advanced, 
which has not only reduced workers’ work intensity, but also improved the operational 
efficiency of the sewage treatment plants, thus has made the scientific administration 
of manufacturing in sewage treatment plants possible.

Key words: PLC, Sewage treatment, SBR reaction

目　　录

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引言

........................................................................1

2 系统总体设计....................................................................................1
3 控制系统设计....................................................................................2

3.1 除渣......................................................................................................................2
3.2 除油......................................................................................................................3
3.3 中和处理..............................................................................................................4
3.4 除有机物..............................................................................................................5
3.5 除盐......................................................................................................................5

4 PLC 选型...........................................................................................6

4.1 PLC 的 I/O 口分配...............................................................................................7
4.2 系统外部接线图..................................................................................................7
4.3 软件设计..............................................................................................................8

5 上位机与下位机的设计.......................................................................9

5.1 上位机设计..........................................................................................................9
5.2 下位机设计..........................................................................................................9
5.3 上位机与下位机之间的通信...........................................................................10

5.3.1 PLC 的通信功能..........................................................................................10
5.3.2 PLC 的通信协议..........................................................................................10

6 通讯网络.........................................................................................13

6.1 中央控制室........................................................................................................13
6.2 控制分站............................................................................................................13
6.3 现场监测仪表....................................................................................................13

7 结束语............................................................................................14
致谢..................................................................................................14
参考文献............................................................................................15

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