【正文】 像許多重要的軟件一樣， LabVIEW 提供了 Windows、 UNIX、 Linux、 Macintosh 的多種版本。 程序框圖 由接線端、節(jié)點、連線和結(jié)構(gòu)等構(gòu)成 。 參數(shù)調(diào)整結(jié)果將在波形圖上動態(tài)顯示出來，可控制信號的采樣頻率與采樣點數(shù)。 因為需要采集硬件信號，所以制作一個簡單的函數(shù) 信號 發(fā)生器。點擊“數(shù)據(jù)采集與分析”控件，進入數(shù)據(jù)采集與分析界面如圖 23所示 。條件結(jié)構(gòu)中的打開 VI 引用路徑是當(dāng)前 VI 路徑，而當(dāng)前路徑是關(guān)閉，所以，結(jié)束 while 循環(huán)的同時 就會 跳出運行界面。 江蘇技術(shù)師范學(xué)院畢業(yè)設(shè)計說明書 （論文） 第 10 頁 共 37 頁 圖 26 屬性節(jié)點 的選擇類型 設(shè)置 VI的屬性時 把屬性節(jié)點關(guān)聯(lián)的類型選為 VI。圖 210是它端點的示意圖。 而使用 LabVIEW 編程產(chǎn)生的虛擬信號發(fā)生器可以穩(wěn)定的產(chǎn)生虛擬波形，圖 形化顯示在波形圖上，并且相應(yīng)的參數(shù)可以調(diào)節(jié)。 基本函數(shù)發(fā)生器各接線端如圖 32 所示，分別有信號類型、頻率、幅值、相位、采樣信息、信號輸出等端口，在連接程序 框圖是，接線端對應(yīng)連接。這樣的變換過程稱為調(diào)制與解調(diào) ,已被廣泛用于傳感器的調(diào)理電路中。經(jīng)過調(diào)制的高頻振蕩波稱為已調(diào)波。 江蘇技術(shù)師范學(xué)院畢業(yè)設(shè)計說明書 （論文） 第 19 頁 共 37 頁 信號調(diào)幅解調(diào) 器功能 該儀器的功能是仿真生成兩個幅值、相位和頻率可調(diào)的正弦波 ， 這兩個仿真的 正弦波一個是高頻信號作為載波信號 ,用來模擬傳感器實驗主機箱提供的音頻振蕩信號 ,另一個是低頻信號作為調(diào)制信號 ,它同時也是用來模擬金屬箔應(yīng)變式傳感器所測得的振動源的原始振動信號。 江蘇技術(shù)師范學(xué)院畢業(yè)設(shè)計說明書 （論文） 第 20 頁 共 37 頁 圖 42 調(diào)幅 解調(diào)器的前面板 調(diào)幅波解調(diào)器 程序框圖 的設(shè)計 虛擬調(diào)制解調(diào)器程序 框圖 如圖 43 所示 ,主要用到了 3個正弦波信號發(fā)生器、巴特沃斯濾波器、捆綁函數(shù)等相應(yīng)節(jié)點來完成調(diào)幅解調(diào)的過程。 基于 LabVIEW 的 數(shù)據(jù)采集卡 對于虛擬儀器系統(tǒng)， 要實現(xiàn) 對外部 數(shù)據(jù)采集 的功能 ，必須 配 有一塊數(shù)據(jù)采集卡。 數(shù)字 I/O 通常用來控制過程、產(chǎn)生測試信號、與外設(shè)通信等。讀取任務(wù) 節(jié)點的采樣模式選擇為“模擬”→“單 通道”→“多采樣”→“波形”，如圖 53 所示。讀取到數(shù)據(jù)后，顯示在波形圖中 并 分析 處理 信號的參數(shù)。本設(shè)計采用由集成運放和 RC 元器件組成方波 三角波函數(shù) 信號 發(fā)生器 [13]。首先，是硬件電路的檢查，利用萬用表檢查點點之間是否有虛焊漏焊的情況，檢查通過后，上電測試，其輸出端接到示波器的輸入端口，產(chǎn)生波形如圖 511所示， 分別顯示方波和三角波， CH1是三角波，其偏轉(zhuǎn)因子是 1V，峰峰值為 左右。這次設(shè)計讓我最深的感受到專業(yè)知識 與理論相結(jié)合的重要性 。存儲問題方面 ，還是以獲取日期時間的方法，把數(shù)據(jù)存入同一文件夾，命名不同。 有人可以僅靠自己的力量獨立的完成一項工作，我的設(shè)計在大量資料的指導(dǎo)前提下進行，最后要感謝那些在虛擬儀器等領(lǐng)域有著卓越建樹的專家學(xué)者，他們的開拓性工作為后輩提供了高起點，為整個社會的發(fā)展做出了巨大貢獻！ 江蘇技術(shù)師范學(xué)院畢業(yè)設(shè)計說明書 （論文） 第 33 頁 共 37 頁 附錄 附錄一 實物圖 江蘇技術(shù)師范學(xué)院畢業(yè)設(shè)計說明書 （論文） 第 34 頁 共 37 頁 附錄二 元器件清單 元器件名 型號 個數(shù) 雙運放 LM358 1 瓷片電容 1uf 1 可調(diào) 電阻 100K 1 可調(diào)電阻 47K 1 電阻 10K 3 電阻 20K 1 電阻 1 導(dǎo)線、插針 若干 江蘇技術(shù)師范學(xué)院畢業(yè)設(shè)計說明書 （論文） 第 35 頁 共 37 頁 附錄 三 中英文翻譯 一、 外文原稿 The Virtual Instrument and Its Instance Electronic measuring instruments is the basis of the electron industry. It occupys a very important position in the industry for a long time. It is the symbol of the developmental level of the electron industry in an era and updating constantly with the development of scientific technology. As a fixed function and long cycle of research and production, and other shortings, the traditional measuring instruments can not meet the demands of information age. So the large developmental space has been supplied for the new type of measuring instrument virtual of the simple construction of the hardware,software achieving a variety of functions mainly, and improving its proformance continuously with the development of the puter. It is provided with strongly adaptability and causes great concern in the world. Virtual machines pletely changed the traditional definition of equipment from the manufacturer function of the model, but in a small amount of additional hardware on the basis defined by the user equipment functions. Because it relies mainly on the operation of the software, modify or add features, improve performance are very flexible and userfriendly PC hardware and software resources and direct use of PC peripherals and working capabilities. Virtual instrument not only low cost, but also by modifying its software to increase the adaptability, thereby extending its life cycle, is a very good development prospects with the equipment. And traditional instruments, virtual instrument is 江蘇技術(shù)師范學(xué)院畢業(yè)設(shè)計說明書 （論文） 第 36 頁 共 37 頁 an efficient, open, easytouse flexible, powerful, costeffective, operational and other obvious advantages of good . Electronic measurement system in the virtual instrument of teaching and research in the application. Colleges and universities in particular, science and engineering school, master measuring instruments and equipment operators to use each student is the basic prerequisite for scientific experiments. Teaching, scientific research requires a large amount of measurement and analysis equipment, especially the experimental teaching, each apparatus must be more than targeted, but some equipment is expensive, so the investment required enormous equipment, it is very difficult to meet in ordinary schools, causing many schools Outdated equipment and lack of phenomena such as outdated, seriously affecting teaching and research. CAI use of educational softwareassisted teaching, can better overe the difficult part. However, because of electronic technology in the teaching of CAI software also small, not strong and functional, interactive, operability and the true extent of poor interface, to narrow the scope, to a certain extent, limited the use of teachers and students of the initiative. If the use of virtual instrument systems, the situation will be quite different. The use of virtual machines will not only save a lot of instruments and equipment for investment, but also can enhance the teaching and research quality and efficiency. Teachers in the classroom can be directly carried out on experimental demonstration of remedial teaching. Such as the mon signal — triangle wave, enter a different frequency, graphics interfac