【正文】 系統(tǒng)為用戶提供了矩形（圓角矩形）、直線、橢圓（圓）、扇形（圓?。?、點位圖、多邊形（多邊線）、文本等基本圖形對象，及按鈕、趨勢曲線窗口、報警窗口、報表等復雜的圖形對象。提供了對圖形對象在窗口內(nèi)任意移動、縮放、改變形狀、復制、刪除、對齊等編輯操作，全面支持鍵盤、鼠標繪圖，并可提供對圖形對象的顏色、線型、填充屬性進行改變的操作工具?！敖M態(tài)王”采用面向對象的編程技術，使用戶可以方便地建立畫面的圖形界面。用戶構圖時可以像搭積木那樣利用系統(tǒng)提供的圖形對象完成畫面的生成。同時支持畫面之間的圖形對象拷貝，可重復使用以前的開發(fā)結果。圖：實際控制系統(tǒng)組成的動態(tài)運行圖1）歷史報警窗口在工具箱中選用報警窗口工具，在面板中繪制報警窗口，添加文本等就可。由于前面已經(jīng)設置了報警變量，所以當變量值超過所設置的溫度時，那就會在報警畫面中被記錄。 歷史報警設置 運行調試中的問題及解決方法運行調試過程中發(fā)現(xiàn)串級控制系統(tǒng)的調節(jié)器參數(shù)整定要比單回路復雜些，這也因為兩個調節(jié)器之間相互影響，且兩個調節(jié)器的任何一個參數(shù)變化對系統(tǒng)都有影響，但用兩步法進行整定還是能有效克服這些問題。 致 謝本論文論述了工業(yè)生產(chǎn)過程中最常見的液位—流量串級控制系統(tǒng)，具有較大的實際意義。在設計中綜合應用了過程控制技術、自動控制原理、組態(tài)軟件控制技術等相關知識，其中組態(tài)軟件控制技術是自動控制系統(tǒng)設計的重要發(fā)展方向。當然，本論文只是對串級控制系統(tǒng)比較淺顯的論述。由于設計的系統(tǒng)為高階系統(tǒng)，為了避免十分繁瑣的理論分析計算，采用了仿真軟件來計算其性能指標，但這樣顯然對自動控制原理的應用就想應減少了。在實驗過程中也發(fā)現(xiàn)，串級控制系統(tǒng)的調節(jié)器參數(shù)整定要比單回路控制系統(tǒng)更加復雜，因為兩個調節(jié)器串在一起，在一個系統(tǒng)中工作，互相之間或多或少有些影響，其中任何一個調節(jié)器的任一參數(shù)值發(fā)生變化時，對整個串級控制系統(tǒng)都具有影響. 另外，由于采用了組態(tài)軟件進行控制，在計算機編程上也相應簡化，未使用其他高級語言的編程方式。總之，本畢業(yè)設計只是對所學知識的一個簡單應用，還有一些較為復雜和細化的問題有待于解決，因此，這次畢業(yè)設計是一個鍛煉的開始?？傊ㄟ^本次畢業(yè)設計，使我將大學四年所學的專業(yè)知識，運用了到了實際當中，從而使我對大學四年所學到知識又有了進一步的加深和拓展，而且學到了很多新的知識，尤其對西門子S7200PLC及其工程應用有了更深刻的認識，更使自己看到了學習中的不足與漏洞，以及對待問題的態(tài)度，我相信這定會給我以后的工作學習打下一個堅實的基礎。在此誠摯的感謝劉老師的精心指導及同學的相互幫助，最后終于完成了本次設計。 參考文獻[1] 徐兵等，過程控制，機械工業(yè)出版社，2004[2] 金以慧等，過程控制，清華大學出版社，1993[3] 薛弘曄等編，計算機控制技術，西安電子科技大學出版社，2003[4] 王化祥，張淑英，傳感器原理及應用，天津大學出版社，1999[5] 陳隆昌等，控制電機，西安電子科技大學出版社，2000[6] 何離慶等，過程控制系統(tǒng)與裝置，重慶大學出版社，2003[7] 施仁等，自動化儀表與過程控制，電子工業(yè)出版社，2003[8] 周雪琴，張洪才，控制工程導論，西北工業(yè)大學出版社，2003[9] 胡壽松等，自動控制原理，科學出版社，2001[10] 薛定宇，陳陽泉，基于MATLAB/Simulink的系統(tǒng)仿真技術與應用，清華大學出版社，2002附 錄程序梯形圖主程序首先進行一系列的狀態(tài)檢測，在檢測均正常的情況下給變頻器上電，啟動變頻器，變頻器正常啟動后就開始調用子程序，首先是PID初始化，然后運算，之后調用輸入轉換，在輸出轉換，最后停止變頻器，結束系統(tǒng)工作。PID初始化PID初始化首先給PID0的P賦值，然后預置采樣時間，再分別給I和D賦值，再給PID1的P賦值，預置采樣時間后在預置其I和D的值，之后開始調用運算。英文原文Bit Logic Instructions ContactsStandard ContactsNormally Closed contact instructions (LDN, AN, ON) obtain，the referenced value from the memory or from the，processimage register. The standard contact instruction so btain the referenced value from the memory (or processimage register if the data type is I or Q)..The Normally Open contact is closed (on) when the bit is equal to 1, and the Normally Closed contact is closed (on),when the bit is equal to 0. In FBD, inputs to both the And Or boxes can be expanded to a maximum of 32 STL, the Normally Open instructions Load, AND, or OR the bit value of the address bit to the top of the stack, and the Normally Closed instructions Load, AND, or OR the logical NOT of the bit value to the top of the stack.Immediate ContactsAn immediate contact does not rely on the S7200 scan cycle to update。 it updates immediately. The Normally Open Immediate contact instructions (LDI, AI, and OI) andNormally Closed Immediate contact instructions (LDNI, ANI, and ONI) obtain the physical input value when the instruction is executed, but the processimage register is not updated.The Normally Open Immediate contact is closed (on) when the physical input point (bit) is 1, and the Normally Closed Immediate contact is closed (on) when the physical input point (bit) is 0. The Normally Open instructions immediatelyLoad, AND, or OR the physical input value to the top of thestack, and the Normally Closed instructions immediatelyLoad, AND, or OR the logical NOT of the value of the physical input point to the top of the stack.NOT InstructionThe Not instruction (NOT) changes the state of power flow input (that is, it changes the value on the top of the stack from0 to 1 or from1 to 0).Positive and Negative Transition InstructionsThe Positive Transition contact instruction (EU) allows power to flow for one scan for transition. The Negative Transition contact instruction (ED) allows power to flow for for each ontooff transition. For the Positive Transition instruction,detection of a in the value on the top of the stack sets the top of the stack value to 1。 otherwise, it is 0. For a Negative Transition instruction, detection of a 1to0 transition in the value on the top stack sets the top of the stack value to 1。 otherwise, it is set to 0..For run mode editing (when you edit your program in RUN mode), you must enter a parameter Positive Transition and Negative Transition instructions. Refer to Chapter 5 for about editing in RUN mode.CoilsOutputThe Output instruction (=) writes the new value for the output bit to the processimage register. When the Output instruction is executed, the S7200 turns the output bit in the processimage register on or off. For LAD and FBD, the specified bit is set equal to power flow. For STL, the value on the top of the stack is copied to the specified bit. Output ImmediateThe Output Immediate instruction (=I) writes the new value to both the physical output and the corresponding processimage register location when the instruction is executed.When the Output Immediate instruction is executed, the physical output point (Bit) is immediately set equal to powerflow. For ST uction immediately copies the value on the top of the stack to the specified physical output bit (STL). The “I” indicates an immediate reference。 the new value is written to both the physical output and the corresponding processimage register location when the instruction is executed. This differs from the nonimmediate references, which write the new value to the processimage register only.Set and ResetThe Set (S) and Reset (R) instructions set (turn on) or reset (turn off) the specified number of points (N), starting at the specified address (Bit). You can set or reset from 1 to 255 points.If the Reset instruction specifies either a timer bit (T) or counter bit (C), the instruction resets the timer or counter bit and clears the current value of the timer or counter. Error conditions that set ENO = 0H 0006 (indirect address)H 0091 (operand out of range)Set Immediate and Reset ImmediateThe Set Immediate and Reset Immediate instructions immedia