【正文】 n, have stronger and , the wastewater treatment is convenient to arrive of the PLC choose the series of Modicon Ouantum of use Schneider. 1． 3 Correspondences MB+agreement is the Modicon pany release of an open type of the adoption IEEE802. 4 correspond by letter 5 agreements the spot total line of card +the work together other works pare to have a set of simple, the investment be little, work speed quick, correspondence the stability strong etc. characteristics, it make calculator, controller and other data sources through an usage double wring line or fiber optic cable Be a body to together carry on correspondence at the whole work the CPU mold piece of the Modicon Quantum series PLC imply MB+correspondence, therefore correspond by letter a work to choose to use MB+ control two machine, two control stations with native PLC of room to pass MB+the work link PLC CPU mold piece passes MB+correspondence and two machines carry on data mutation and collect the place of honor supervision various operation instruction of the system and the spot the examination signal and data, through analysis handle, pass exportation mold piece to control object output control signal。 the software program of designs uses Intouch7. 0. The specific technology, equipment, the controlling of main parameter and several running data are uncharged of the PLC stations, and the software program of designs uses Concept with online tracking and outline simulating. MB+ is adopted by the munication between the upper puter and the PLC stations, with its simply build ing, quickly running and stable munication. The automatic control of PLC has been successfully pleted in sewage treatment, which has improved the operation efficiency and management level of sewage treatment equipment Introduced to take PLC as the distribute type control system of core in the wastewater treatment system of described the structure, mission of the control system an allotment and carry out, the way of control and the thought of the program design. The way controled the concentration monitor of the system adoption a management and scattered a control, the place of honor machine be responsible for the spot the long range of the equipments control and surveillance, software adoption Intouch7. 0 draw PLC native station is responsible for to the concrete craft, equipments and is mainly controled parameter to carry on control and collect various movement data, the program design adoption have online follow with offline imitate the Concept of true function 2. 2 XL of honor machine and of the PLC adoption set the be quickly simple and circulate speed, correspond by letter the stability strong MB+ whole control system successfully solved the PLC controls a problem in the automation within wastewater treatment and raised a wastewater treatment equipments to circulate an efficiency and manage level. Recently, for carrying out high quality, low consume, stable dependable and international many wastewater treatment factorieses adopted a modern forerunner to control technique and calculator technique and constitute calculator direct, control thus, manage system excellent to turn the programmable logic controller(PLC) then take microprocessor as the calculator technique automatically controls technique and correspondence technique but develops of a kind of new and in general use utomatic control structure simple, function superior, dependable sex Gao, work properly words in general use, be easy to plait distance, usage convenience etc. advantage etc..The silver Chuan City the first wastewater treatment factory adopted a SBR craft and take PLC as the control system of core, day after handling the sewage 10 104 t the processing of reach mark sewage can used for an agriculture irrigation. 1 Control system structure Control the way of concentration monitor management, scatter a control of the system emulation hold, place of honor machine, gather a line machine, printer to Be located on medium control room, two set PLCs are located on control the this kind of structure can make the information in the production line can centralized management with carry out whole operation, management with excellent make to control dangerous dispersion in the meantime, raise the system credibility. 1． 1 The upper puters Medium control two calculator adoption PII class works of room to control machine, circulate the operate system of Windows place of honor machine be responsible for on the scene establish each long range control(fullautomatic control, automatic control, order to move a control) with surveillance, make use of Intouch7. 0 engineering software packages provide a good person machine dialogue boundary but obtain concerning parameter and equipments appearance information from the PLC by searching a way, keep a view manifestation to e out on the CRT by good sketch type, print a necessary data in the meantime and be provided for lord to control and manager instruction and control boundary but include the system total diagram, system cent diagram, imitate the quantity general chart, parameter a constitution, report to the police a window, history trend and register a window etc. boundary the system total diagram, circulate the personnel can keep watch on signals, such as all movement appearances, equipments trouble and liquid which control an equipments and discharge...etc..Operate a personnel in the system the cent the diagram can carry on a single machine point to move to circulate an operation to all control equipmentses, bee the set automatically circulate operation or the whole factorieses fullautomatic operation bine the meantime place of honor machine 2 and do a plait distance a control room to establish another an inset type emulation to hold, is been one control by the place of honor machine, in order to keep the craft process of the view manifestation whole fact