摘要:虚拟仪器(Virtual Instrument，简称VI)是仪器技术与计算机技术深层次结合的产物，它是全新概念的仪器，使测量仪器与计算机之间的界限消失，是对传统概念仪器的重大突破，是仪器产业发展一个重要方向。
本文首先论述了虚拟仪器的发展、特点、概念及其意义，介绍了 LabWindows/CVI的开发平台及集成环境；然后重点阐述了基于LabWindows/CVI的虚拟信号发生器的设计过程，实现了波形的幅值、频率、相位和采样频率均可调的三角波、正弦波、方波及锯齿波等四种波形的发生器；最后采用网络通信中间件Data Socket技术，将信号发送到远程计算机，实现了网络化信号发生器。
本文设计的基于LabWindows/CVI的虚拟信号发生器与传统的信号发生器相比，具有性能价格比高，功能扩展性好，开发周期短、实用性强等众多优点。
关键词 虚拟仪器；信号发生器；LabWindows/CVI；DataSocket
Abstract:Virtual instrument (listed VI) is the deep-level product of the instrument technology and computer technology. It is a brand-new concept of the apparatus, makes the line between measurement equipments and computers disappear. It is a major breakthrough to the concept of traditional equipment. It is an important development direction to equipment industry.
This paper first discusses the development, features, concept and significance of virtual instrument, and introduces the platform for the development and integration environment on the LabWindows / CVI. Then it focuses on the design process of the virtual signal generator based on LabWindows / CVI. The signal generator can realize four waveforms such as the triangular wave, sine wave, square wave and saw tooth wave. And the amplitude, frequency, phase and sampling frequency of the waveforms can be adjusted. Finally with the network communication middleware Data Socket technology, the signal is sent to the remote computer. Thus, we can achieve a network of virtual signal generator.
To compare with the traditional signal generator, the virtual signal generator based on LabWindows/CVI will have a high cost performance, good functional scalability, short development cycle ,strong practicability and many other advantages.
Keywords virtual instrument signal generator LabWindows/CVI DataSocket
目前，在一些发达国家虚拟仪器技术非常先进，虚拟仪器产品广泛地应用在工业控制、通讯、自动化、电子、电力、生化制药和工业生产等各种领域。而在我国基本上还处于传统测试仪器与计算机脱离的状态，其发展潜力很大，因而研究与应用虚拟仪器技术可以迅速发展我国的仪器产业，对提高工业界的测试水平具有深远的意义。
虚拟仪器对测量仪器发展的深刻意义还在于，虚拟仪器的功能可以由用户根据需要自行设计软件来定义和扩展，而不是像传统仪器那样，功能只能由厂家事先定义并且固定不可变更。这样，用户不必购买多台不同功能或是昂贵的集多种功能于一体的传统仪器，也不必不断购买新的仪器。因为虚拟仪器与计算机同步发展，与网络及其他外部设备互连，用户只需根据需要改变软件程序就可以不断赋予或者扩展增强它的功能，从这个意义上说，意义的设计及制造不再是仪器厂家的专利。虚拟仪器开创了仪器使用者可以成为仪器设计者的时代，这将给仪器使用者带来无尽的收益。
