The Application Of PLC In Measure And Control System Of Polluted Water Pump Station

Traditional polluted water system, which uses relay to regulate and control, is easy tofloat and unable to intelligence. So it can't assure pump station to immediate and reliablemovement, while micro-control machine based on chip processors isn't good atanti-interference. Its occasional service condition is necessary, so the running state aboutpolluted water pump station can't be properly known at once. The use of PLC can makesystem stable, reliable, up to condition free of repair.The article, which aims at polluted water pump station's function and PLC'steeh-eharacter, studies test and control system based on DCS. The system which uses a seriesof ST-200 SIEMENS small PLC as long-distance terminal, is one point to multi-point monitornet which uses industrial PC as upper machine. Industrial PC set in central control room ofprocessed polluted water in the factory, is both upper machine and a working station in theprocessing factory of computer LAN , Through self-definition wireless communicationmodule, realizes data communication with pump stations, also by time and accidenthappening, works out best balance water quantity and conditioning water among pumpstations. Down machine set in pump station, according to upper machine's order, controlspumps and valves, consists of local data collecting system. According to limited given water,it dispatches water, regulates starting pumps and working time to reach the aim.All pump stations places are decentralized, processing factories centralize data to dealwith and monitor. This character agrees with DCS system. From this point, distributed controlsystem can suit this system better, simultaneously, it can meet central display and print in themiddle control room, controls all system's moving state and parameter's need. System'sunified design makes its function properly distributed to systems, has avoided repeatedfunctions and compaction among systems. So it makes systems repair convenient, decreasesspare parts, has offered the whole pump station's movement advantages, improved moving and managing staff, lowered labor, resources and careless omission, improved system'sreliability.