【正文】 oduction equipment ponents wellknown pany) produced a SCX11122 multiplexer, SCX1 a 1122 maximum 16channel, Strain gauge conditioning, thermistor, RTD, thermocouple voltage signal and munication, process control switch the type of signal conditioning. In accordance with the use of the puter is a laptop or desktop, choose different data acquisition board. In order to facilitate the portability of this equipment is used in portable puters. NI data acquisition card is a Ai Corporation DAQCard a 16XE a 50 for 16bit A / D converter sampling rate for single200K, multichannel at 20K. The measurement accuracy of this instrument to percent. 16 of the A / D fully meet this requirement。s customers do not understand the acquisition card interface circuit and principles of the instrument can be modified or expanded features. Measuring the parameters of modular software structure, is a reasonable division of the measurement modules, and enhance the use of mon parts of the general, and to provide the parameters of the plex graphics and tables output. Calibration and error correction module, not only on the sensor can be calibrated to amend the source of error, but also the use of the average, and so on the relevant calculation of inhibition and to reduce interference and improve the measurement accuracy and increase the reliability of measurement. The apparatus of the software used NI39。 [關(guān)鍵詞 ] 虛擬儀器 。 中圖分類號(hào) :TAB24。計(jì)算機(jī)技術(shù)的發(fā)展和應(yīng)用 , 給儀器儀表領(lǐng)域帶來了深刻的變化 , 特別是虛擬儀器的產(chǎn)生和應(yīng)用 , 可以說是儀器領(lǐng)域的一次革命 , 但長期以來 , 不論是在我們的物理教學(xué)活動(dòng)中 , 還是傳統(tǒng)儀器占主導(dǎo)地位 , 計(jì)算機(jī)與測(cè)量?jī)x器基本上還處于互不相關(guān)的狀態(tài) , 這必將大大影響我們對(duì)于先進(jìn)儀器的了解和掌握 , 因此學(xué)習(xí)一些虛擬儀器的基本知識(shí)是頗必要的。它由通用個(gè)人計(jì)算機(jī) , 模擬化功能硬件和控制軟件組成。虛擬儀器具有以下幾個(gè)特點(diǎn)。 。 , 容易實(shí)現(xiàn)升級(jí)、虛擬儀器的硬件結(jié)構(gòu)是相對(duì)固定的 , 而軟件卻具有很大的靈活性 , 對(duì)軟件或操作系統(tǒng)升級(jí)后 , 虛擬儀器就可以更新、換代。 二、儀器構(gòu)成和工作原理 用一臺(tái)儀器完成多個(gè)參數(shù)的測(cè)量一直是測(cè)試領(lǐng)域的一個(gè)實(shí)際問題 , 用傳統(tǒng)儀器往往很難實(shí)現(xiàn)。 采用虛擬儀器的設(shè)計(jì)方法 , 可以方便地實(shí)現(xiàn)對(duì)多個(gè)參數(shù)的測(cè)量 , 本儀器可以測(cè)試溫度、力值、壓力、位移、機(jī)械振動(dòng) 5個(gè)參數(shù) , 共 6個(gè)通道 , 各通道測(cè)試功能具有交換性 , 可同時(shí)測(cè)量一種或多種參數(shù)。使用數(shù)據(jù)采集卡完成 A/D轉(zhuǎn)換最后由計(jì)算機(jī)完成數(shù)據(jù)的分析、處理。用戶利用 鼠標(biāo)或鍵盤直接在虛擬面板上進(jìn)行操作 , 即可輕松完成各種參數(shù)的測(cè)試、分析、打印等功能。本 儀器的硬件主要由傳感器、信號(hào)同理器、數(shù)據(jù)采集卡和計(jì)算機(jī)四部分組成。例如力值測(cè)量范圍為01KN, 測(cè)量精度 %（ ） , 則需用測(cè)量上限分別為 蓋其測(cè)量范圍。 按照使用的計(jì)算機(jī)是臺(tái)式機(jī)還是便攜機(jī) , 可選擇不同的數(shù)據(jù)采集板。數(shù)據(jù)采集卡是 NI公司的 DAQCard一 Ai一 16XE一 50, 為 16位 A/D轉(zhuǎn)換器采樣速率單通道方式為 200K, 多通道時(shí)為 20K。 16位的 A/D完全可滿足這一要求 。 四、軟件設(shè)計(jì) 軟件是虛擬儀器的核心 , 軟件的設(shè)計(jì)質(zhì)量 , 直接影響虛擬儀器的性能。本儀器的軟件主要由數(shù)據(jù)采集卡驅(qū)動(dòng)模塊、虛擬面板模塊、各參數(shù)測(cè)量模塊、校準(zhǔn)及誤差修正模塊四部分組成。本儀器的面板布局合理 , 易于操作 , 具有高度的人機(jī)交互性 , 用戶的每一步操作都能得到提示和即時(shí)響應(yīng) , 并提供在線助。有開發(fā)能力的 用戶 , 不需了解采集卡的電路結(jié)構(gòu)和接口原理 , 便能對(duì)儀器功能進(jìn)行修改或擴(kuò)展。 校準(zhǔn)及誤差修正模塊 , 不僅可對(duì)傳感器進(jìn)行校準(zhǔn) , 對(duì)誤差源進(jìn)行修正 , 而且還采用平均、相關(guān)等計(jì)算方法 抑制和降低干擾 , 提高測(cè)量精度和增加測(cè)量的可靠性。 五、結(jié)束語 用虛擬儀器實(shí)現(xiàn)多參數(shù)的測(cè)量能夠簡(jiǎn)化硬件 , 極大地降低儀器的成本 , 增加測(cè)試的可靠性。隨著計(jì)算機(jī)在我國的進(jìn)一步普及 , 虛擬儀器必將得到越來越廣泛的應(yīng)用 , 也必將對(duì)物理教學(xué)作出更大的貢獻(xiàn)。 digital oscilloscope。 With the development of puter technology and traditional instruments to the puterized direction. Virtual instrument is the new 9039。s highend desktop machines such as digital oscilloscope, spectrum analyzer, logic analyzer and others rely mainly on imports, these machines processing plex, requiring high levels of manufacturing, production breakthroughs have difficulty using virtual instrument technology can only procurement of the necessary general data acquisition hardware to design their own equipment system。s desktop dualchannel digital storage oscilloscope HP54603B functions, and instrumental analysis and processing functions have expanded. Instrument main features include: dualchannel signal input, trigger control, access control, timebase control, waveform display, parameter automatic measurement, spectrum analysis, waveform, such as storage and playback. The virtual digital oscilloscope also provides work interface, allowing the adoption of TCP / IP protocol work sharing or remote control apparatus. Table 1 is the virtual digital oscilloscope with HP54603B function table. In addition to financial reasons make the selected sampling rate data acquisition card HP54603B below, this virtual oscilloscope display, measurement, analysis, storage and external connections so as not less than even higher than HP54603B 2 Software Design and Implementation Software Development Environment Virtual Digital Oscilloscope software design using advanced graphical programming language LabVIEW for Windows98/NT. The main features of LabVIEW programming is divided into a number of virtual instruments basic function modules (equivalent to hardware design of integrated circuits), the representative pin module input / output interface. Programmers through interactive means, the use of graphical block diagram design method to plete the virtual instrument measurement and analysis of the logic and functional design. LabVIEW program design process and design equipment people very close to the thinking process, the program block diagram on the realization of the program code function, to avoid a general idea of program design from the diagram to the process by cutting red tape. Another advantage of LabVIEW programming is the software interface design and functional design to an independent open, modify interactive interface to the entire process without debugging, which is designed as instruments of such a plicated operation panel in terms of manmachine interface is very convenient. LabVIEW also provides a function for users to expand functionality, the use of LabVIEW in the Code Interface Node (CIN), can call using the traditional C programming language to write code。 ? Select th