【正文】 基于 LabVIEW 虛擬示波器的 設(shè)計(jì) 摘 要 當(dāng)今世界信息與計(jì)算機(jī)技術(shù)發(fā)展日新月異，軟件開(kāi)發(fā)技術(shù)更是不可同日而語(yǔ)。在數(shù)據(jù)采集、實(shí)時(shí)分析與處理、顯示與存儲(chǔ)等方面，基于計(jì)算機(jī)的虛擬儀器技術(shù)比傳統(tǒng)儀器有著明顯的優(yōu)勢(shì)。由于傳統(tǒng)儀器功能單一且價(jià)格長(zhǎng)期居高不下，計(jì)算機(jī)性?xún)r(jià)比卻不斷提升，因此虛擬儀器的發(fā)展已是大勢(shì)所趨。美國(guó) NI 公司率先發(fā)起對(duì)虛擬儀器的研究與開(kāi)發(fā)，建立了 LabVIEW 軟件開(kāi)發(fā)平臺(tái)。以計(jì)算機(jī)為輔助的虛擬儀器技術(shù)，推動(dòng)了傳統(tǒng)儀器朝著智能化、數(shù)字化、網(wǎng)絡(luò)化、模塊化、人性化的方向發(fā)展。 本文基于 LabVIEW 虛擬儀器開(kāi) 發(fā)平臺(tái)，設(shè)計(jì)虛擬示波器界面，實(shí)現(xiàn)數(shù)據(jù)采集、濾波處理、時(shí)域分析、頻域分析、波形存儲(chǔ)與讀取等功能，程序調(diào)試、演示設(shè)計(jì)結(jié)果，分析系統(tǒng)性能。 關(guān)鍵詞 虛擬儀器 ， 虛擬示波器 ， 頻域分析 ，數(shù)據(jù)采集 ABSTRACT In the contemporary world, information and puter technology develop rapidly with each passing day. The Software Development Technology is quite different, too. Compared with the traditional instrument technology, the virtual instrument technology based on puter has more advantages from the aspects of data acquisition, realtime analysis and processing, display and storage. Because of traditional instruments’ single function and high price for always and the continuous improvement of puters’ cost performance, the technology of virtual instrument is irreversible. The NI (National Instrument) took the lead in the technology of virtual instrument research and development, and established the LabVIEW software development platform. The technology of puterassisted virtual instrument promoted the traditional instruments to the direction of intelligent, digitizing, working, modular and userfriendly. This article, based on LabVIEW virtual instrument development platform, design virtual oscilloscope interface and realize the function of data acquisition, filtering process, time domain analysis, frequency domain analysis, waveform storage and recall, and debug program, illustrate design results, analyze the system performance. KeyWords: Virtual instrument, Virtual oscilloscope, Frequency domain analysis, Data acquisition 目 錄 1 緒論 .............................................................................................................................. 1 前言 .................................................................................................................... 1 設(shè)計(jì)背景與意義 ................................................................................................... 1 國(guó)內(nèi)外現(xiàn)狀 .......................................................................................................... 2 設(shè)計(jì)研究方案 ...................................................................................................... 2 ................................................................................................................ 3 虛擬儀器系統(tǒng)的組成 ............................................................................................ 4 虛擬儀器的構(gòu)成 ................................................................................................... 5 虛擬儀器的硬件系 ...................................................................................... 5 虛擬儀器的軟件系統(tǒng) .................................................................................. 5 虛擬儀器與傳統(tǒng)儀器優(yōu)缺點(diǎn)對(duì)比 .......................................................................... 6 的軟件概述 .................................................................................................... 7 軟件的特點(diǎn) ........................................................................................... 7 LabVIEW 程序的構(gòu)成 .......................................................................................... 8 LabVIEW 的操作選板 ........................................................................................ 10 4 傳統(tǒng)示波器與虛擬示波器 ............................................................................................ 12 傳統(tǒng)示波器 ........................................................................................................ 12 傳統(tǒng)示波器工作原理 ................................................................................ 13 傳統(tǒng)示波器的分類(lèi) .................................................................................... 14 虛擬示波器 ........................................................................................................ 14 虛擬示波器的組成結(jié)構(gòu) ............................................................................. 15 虛擬示波器的性能指標(biāo) ............................................................................. 15 傳統(tǒng)示波器與虛擬示波器對(duì)比 .................................................................. 16 ................................................................................................ 17 數(shù)據(jù)采集模塊 .................................................................................................... 18 數(shù)據(jù)采集系統(tǒng)的構(gòu)成 ................................................................................ 19 采樣原理 .................................................................................................. 20 用戶登陸界面 .................................................................................................... 21 虛擬示波器主界面 ............................................................................................. 23 濾波模塊 ........................................................................................................... 26 時(shí)域分析與參數(shù)測(cè)量模塊 ................................................................................... 28 頻譜分析模塊 .................................................................................................... 29 波形存儲(chǔ)和回放 ................................................................................................ 30 ............................................................................................ 32 程序調(diào)試 ........................................................................................................... 32 虛擬示波器數(shù)據(jù)顯示 .......................................................................................... 33 噪聲干擾的防止方法 .......................................................................................... 37 7 總結(jié)與展望 ...................................................................