【正文】 arameters 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。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。 由于 Inter 的快速發(fā)展，希望能夠通過(guò) Inter 來(lái)訪問(wèn)污水處理廠的自控系統(tǒng)，只需要輸入用戶名和密碼便可實(shí)現(xiàn)遠(yuǎn)程的 Inter 來(lái)對(duì)全廠的設(shè)備進(jìn)行控制。如遇到意外情況使輸出電流超過(guò)額定值時(shí)，立即降低風(fēng)機(jī)轉(zhuǎn)速。 SBR 池的進(jìn)氣閥、進(jìn)水閥、回流泵、剩余污泥泵 由 PLC 根據(jù)污水處理周期的工藝時(shí)間段控制，出水閥由 PLC 根據(jù)工藝時(shí)間和超聲液位儀的測(cè)量值來(lái)控制。對(duì)日處理10 x 104 t 的 4 組 8 池模式的 SBR 反應(yīng)池，每組反應(yīng)池配一臺(tái)由變頻器控制的風(fēng)機(jī)，用于向兩個(gè)曝氣池輪流曝氣供氧。 2 PLC 控制程序設(shè)計(jì) 系統(tǒng)有四種控制方式：本地手動(dòng)控制，單一臺(tái)設(shè)備點(diǎn)動(dòng)控制，成組設(shè)備自動(dòng)控制，全廠設(shè)備全自動(dòng)控制。 現(xiàn)場(chǎng)各個(gè)監(jiān)控點(diǎn)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(duì)應(yīng)的一次儀表傳感器或變送器檢測(cè)出來(lái) 并轉(zhuǎn)變?yōu)?4～ 20 mA 電流信號(hào)，經(jīng)屏蔽電纜送到各個(gè)子系統(tǒng)的 PLC 內(nèi)，由 PLC 通過(guò)各種模塊接口采樣電信號(hào)。 上位機(jī) 中控室的兩臺(tái)上位計(jì)算機(jī)采用 PII 級(jí)工控機(jī)，運(yùn)行 Windows NT 操作系統(tǒng)。而可編程邏輯控制器（ PLC）則是以微處理器為核心。外文翻譯 基于 PLC 的控制系統(tǒng)在污水處理中的應(yīng)用 介紹了以 PLC 為核心的分布式控制系統(tǒng)在污水處理系統(tǒng)中的應(yīng)用。綜合了計(jì)算機(jī)技術(shù)自動(dòng)控制技術(shù)和通信技術(shù)而發(fā)展起來(lái)的一種新型、通用的自動(dòng)控制裝置。上位機(jī)負(fù)責(zé)現(xiàn)場(chǎng)設(shè)各的遠(yuǎn)程控制 (全自動(dòng)控制、自動(dòng)控制、點(diǎn)動(dòng)控制 )和監(jiān)視，利用 Intouch7. 0 工程軟件包提供良好的人機(jī)對(duì)話界而，以查詢方式從 PLC 獲取有關(guān)參數(shù)和設(shè)備狀態(tài)信息，以棒圖形式在 CRT 上直觀顯示出來(lái)，同時(shí)打印必要的數(shù)據(jù)，供主控及管理人員指導(dǎo)生產(chǎn)。同樣，模擬量控制信號(hào)由 PLC 輸出后以 4～ 20mA 電流形式送到執(zhí)行機(jī)構(gòu)，控制執(zhí)行機(jī)構(gòu)的動(dòng)作。前二種方式一般只在設(shè)各調(diào)試或維修時(shí)使用，系統(tǒng)主要以全自動(dòng)控制方式運(yùn)行。在每個(gè)曝氣池的不同地點(diǎn)設(shè) 4 塊溶解氧測(cè)試儀，測(cè)量池中污水的含氧量， PLC 每隔 5 min 檢測(cè)一次曝氣池內(nèi)的溶解氧值，根據(jù)溶解氧的平均值來(lái)控制風(fēng)機(jī)轉(zhuǎn)速。 （ 3）斷電保護(hù)模塊 —— 系統(tǒng)斷電后， PLC 將所有狀態(tài)鎖存，待加電后使 PLC恢復(fù)所保持的狀態(tài)繼續(xù)運(yùn)行。如果風(fēng)機(jī)轉(zhuǎn)速降到允許的最低轉(zhuǎn)速時(shí)，輸出電流還超過(guò)額定值，則停風(fēng)機(jī)，同時(shí)發(fā)出報(bào)警信號(hào)。同時(shí)通過(guò) Inter 將污水處理廠的污水?dāng)?shù)據(jù)輸送到國(guó)家環(huán)保總局或者市環(huán)保局，以便卜級(jí)部門(mén)對(duì)污水處理廠的管理。t need to operate a personnel an spot data spreads a highest machine through a PLC, e out in the place of honor on board description and make the craft, equipments movement of whole factorieses get an overall control. The living creature processing part of the PLC3 station control is the whole wastewater treatment of key part, be limited by space, only with the PLC3 stand of program design for example. Process of control The PLC3 stationses were use to control to get into Pu spirit from sewage, the pond is everywhere sewage run off Pu after manage spirit the whole process of the turn of sequence and time switch moderate breezes machine of control various valve, pump, breeze machine to soon regulate etc. in this Pu spirit pond is the core of wastewater treatment to construct a thing, sewage is to e and go through a microbial living creature oxygenation in the pond in addition to organic matter, the processing effect of content to sewage of the oxygen in water is to go to a pass according to the SBR craft, the deliquescence oxygen in the Pu spirit pond content usually controls within the scope of 1~3 mgs/L and annoy a stage end to fuse an oxygen content in the Pu should be not over the 2 mgs/ the oxygen once measured low or lead Gao, all will influence a fluid matter 4 sets of the 10 104 t the SBR of 8 pond modes