this article mainly introduced PLC in the urban sewage processing concrete application, the system introduced the urban sewage processing technical process as well as based on SIEMENS S7-400 the series PLC sewage treatment implementation plan, introduced the Urban sewage treatment plant supervises the spatial system data acquisition the method. In order to enhance the Sewage treatment plant the operational guidance level, PLC is this system's important composition unit, various units according to certain topology interconnection constitution Sewage treatment plant control system. The findings indicated that this system not only has the strong parallel coordinated handling ability, and has the redundant reliability, the flexibility and the extendibility, as well as merits and so on high speed handling ability. Unifies some Sewage treatment plant automation control system's operational aspect, introduced that the Sewage treatment plant the equipment composition, the automation control mode and the PLC various workstations' function, the network constitution in sewage treatment's application, summarize the automation control system to raise the production efficiency, to reduce the site operators, to enhance the secure display the good results.
key word sewage treatment; Automation control system; PLC; Hardware disposition; Software design.
