【正文】 ory and main parameter value. 1． 2 The PLC stand According to wastewater treatment of two part, the spot the long range of the equipments the control output and the spot the signal collect to control a station pletion from two PLC wood native control station control the space grid, sewage promote a pump house, Pu spirit to sink sand pond39。外文資料 Application of Control System on the Base of PLC in powersupply system The paper introduces a distributed control system of sewage treatment, and the core of the system is PLC. The structure of the control system, the assignment and implementation of the tasks, the control scheme and the design concept of program are expounded. The way of central monitoring management and dispersing control is used by the control system。 the long 一 distance control and monitoring of field equipment are uncharged of the upper puter。s etc. to prepare a processing PLC2 native control station controls dirty mire to dehydrate, press to filter machine etc. department..PLC3 native control station control SBR living creature processing , the on the spot native control station is each to establish an operation terminal to establish each, be responsible for at native to establish each control on the scene.（ automatic control, order to move a control） The spot is each the physical parameter that the supervision order and include water level, temperature, discharge and turn soon, electric current39。In the meantime, the PLC passes MB+ upward the machine return to various data, place of honor machine logarithms according to carry on an operation processing, show various signal and print various statement. 2 The design of PLC control program The system has four kinds of control methods:The native hand moves a control, single set equipments point moves a control, bee a set, the equipments automatically controls, the whole factory equipments fullautomatic kinds of ex with general methods at establish each adjust to try or maintain usage, the system is mainly circulate with fullautomatic this kind of way, all each kind of equipmentses from PLC according to in advance draw up of procedure auto control, don39。If fuse oxygen Gao while set upper limit, the frequency modulation breeze machine turns to soon lower 5%.So, carried out Pu spirit pond to provide automatically regulate of the amount of oxygen, since avoided unnecessary energy loss, again excellent turned movement craft. 2． 2 The design of PLC program The adoptive plait distance software is a Concept 2. 2 is according to under the Windows of the PLC plait distance tool, have good customer39。When fuse an oxygen value small at the 2 mgs/L, the breeze machine turns to soon rise 5%.If the breeze machine turns to soon rise to allow of tallest turn soon, fuse an oxygen value return small then maintain tallest to turn soon at the 2 mgs/ kind of circumstance may annoy the last phase of period to appear in the Pu, but also will not clearly influence wastewater treatment quality. Supervise and control an exportation electric current of change the Pin machine value at any time in the Pu the spirit of the whole period, make it not exceed change the sum of Pin machine settle a meet a surprised circumstance to make to output electric current exceed when the sum settle value, immediately lower breeze machine to turn the breeze machine turns to soon decline to allow of lowest turn soon, output electric current to return exceed the sum settle a value, then stop breeze machine and send out to report to the police signal in the meantime Along with automatic control technical development, the UNITANK craft more and more gets extensively experience as principle currently, use DO, time, discharge as a craft control parameter, adjust the Pu spirit circulate of machine and line up mire the etc. lack accurate mathematics model to carry out the automatic control of higher layer of SBR method for once put forward took the COD or the do as parameter of misty control of research direction of the automatic control of SBR method mainly is to look for several control parameters from now on, since can reflect into water of fluid matter water quantity variety and reaction process in of decline a solution circumstance, and then can do for the calculator control parameter. The PLC gathers in proper order control and process to control at the integral whole and have dependable sex Gao, usage convenience, vivid, set simple of the characteristics be the emollient tool of the small scale industrial automation in the the wastewater treatment, according to PLC control system at solid sex, credibility, accurate sex etc. dint a but satisfied a design a request, promised wastewater treatment of smoothly progress. Because of Inter fast development, hope can e to visit to ask wastewater treatment factory through an Inter of from control system, the Inter which needed to input user39。具體敘述了 控制系統(tǒng)的結構、任務分配及實現(xiàn)、控制方式和程序設計思想 .控制系統(tǒng)采用集中監(jiān)測管理、分散控制的方式，上位機負責現(xiàn)場設備的遠程控制和監(jiān)視，軟件采用 Intouch7. 0 編制。上位機與 PLC 之間采用組網(wǎng)簡單、運行速度快、通信穩(wěn)定性強的 MB+網(wǎng) 。 近年來，為了實現(xiàn)高質(zhì)量 、低消耗、穩(wěn)定可靠的運行。而可編程邏輯控制器（ PLC）則是以微處理器為核心。具有結構簡單、性能優(yōu)越、可靠性高、靈話通用、易于編程、使用方便等優(yōu)點等。 1 控制系統(tǒng)結構 控制系統(tǒng)采用 “集中監(jiān)測管理，分 散控制 ”的方式。采用這種結構可使生產(chǎn)過程中的信息能夠集中管理，以實現(xiàn)整體操作、管理和優(yōu)化。 上位機 中控室的兩臺上位計算機采用 PII 級工控機，運行 Windows NT 操作系統(tǒng)。監(jiān)控界而包括系統(tǒng)總圖、系統(tǒng)分圖、模擬量一覽表、參數(shù)設置、報警窗、歷史趨勢、登錄窗等界而 .在系統(tǒng)總圖里，運行人員能夠監(jiān)視所有控制設備的運行狀態(tài)、設備事故及液位、流量等信號 .在系統(tǒng)分圖里，操作人員能夠?qū)λ锌刂圃O備進行單機點動運行操作、成組自動運行操作或全廠全自動操作并監(jiān)視。 PLC 站 根據(jù) 供電系統(tǒng) 的二部分，現(xiàn)場設備的遠程控制輸出和現(xiàn)場信號 采集由二個PLC 木地控制站完成。 PLC2 本地控制站控制污泥脫水、壓濾機等部。 現(xiàn)場各個監(jiān)控點的物理參數(shù)，包括水位、溫度、流量、轉(zhuǎn)速、電流等模擬量，由對應的一次儀表傳感器或變送器檢測出來并轉(zhuǎn)變?yōu)?4～ 20 mA 電流信號，經(jīng)屏蔽電纜送到各個子系統(tǒng)的 PLC 內(nèi)，由 PLC 通過各種模塊接口采樣電信號。 施耐德公司的 Modicon Quantum 系列 PLC 為滿足開放的、基于標準的網(wǎng)絡連接和現(xiàn)場總線連接等應用技術提供了多種網(wǎng)絡選擇，支持 Modbus,Modbus Plus（ MB+），遠程 I/0, TCP/IP 等網(wǎng)絡連接，具有較強的靈活性。 通信 MB+協(xié)議是 Modicon 公司推出的一個開放式的采用 IEEE802. 4 令牌協(xié)議的現(xiàn)場總 線通信 5 協(xié)議。而 Modicon Quantum 系列 PLC 的CPU 模塊含有 MB+通信口，因此，通信網(wǎng)絡選用 MB+網(wǎng)絡 .中控室的兩臺上位機、二個 PLC 本地控制站通過 MB+網(wǎng)