测控技术及仪器本科毕业设计论文外文翻译译文-vi的使用(编辑修改稿)

测控技术及仪器本科毕业设计论文外文翻译译文-vi的使用(编辑修改稿)内容摘要：

ss VI，您可以交互式地创建一个测量通道或任务。 为了使用 NIDAQmx 进行数据采集，在程序框图上放置 DAQ Assistant Express VI 13 对通道和任务进行设置。 NIDAQmx 是一个用于与数据采集设备通信的程序设计界面。 对 NIDAQmx 支持的设备，可以使用 DAQ Assistant Express VI 对仪器进 行控制。 关于 DAQ 助手的信息请参见在帮助指南中的 Taking an NIDAQmx Measurement in LabVIEW。 选择 HelpTaking an NIDAQ Measurement in LabVIEW 启动帮助指南。 可以在国家仪器公司的网站上查询 NIDAQmx 支持的设备种类，网址为。 如果 NIDAQmx 不支持您所使用的设备，请在 LabVIEW 测量手册中查询有关使用 Traditional NIDAQ 进行数据采集的信息。 任务 在 NIDAQmx 中，任务是一个或多个通道，计时，触发和其他应用于该任务的其它属性的集合。 从概念上讲，任务代表执行的测量或输出功能。 举例来说，您 可以为模拟信号输入功能设定一个通道集合。 在创建一个任务以后，您不需要对每条通道进行设置以实现模拟信号输入功能，而只需使用一个任务。 创建任务以后，可以从任务中添加或删除通道。 在 LabVIEW Measurement Manual (测量手册 )中获得更多关于通道和 任务的信息，请参见第五章中的 Channels Versus Tasks 部分中的 Creating a Typical Measurement Application。 Instrument I/O Assistant Express VI 仪 器驱动是一套用于控制可编程仪器的软件程序。 每个程序协调一项程 序化的功能，例如设置，读取，写入和触发仪器。 国家仪器公司在线提供了上千种仪器驱动程序。 访问 NI 仪器驱动网站（ Instrument Driver Network）查询您需要的仪器驱动，网址为。 如果没有你 所需要的仪器驱动，可以使用 Instrument I/O Assistant Express VI 来与仪器进行通信。 可以使用 Instrument I/O Assistant 与串口，以太网或 GPIB 进行通信并 图形化地分析返回的结果。 可以将 Instrument I/O Assistant Express VI 放置在程序框图上来启动 Instrument I/O Assistant，也可以在程序框图上双击 Instrument I/O Assistant Express VI 的图标来打开它。 参见 Instrument I/O Assistant Help 获取更多关于与外部设备进行通信的信息。 14 指导教师意见： 指导教师签 字 ： 年 月 日 系 (教研室 )意见： 主任签字： 年 月 日 注： 此表单独作为一页。 15 本科毕业设计（论文）外文翻译原文 学生姓名： 王大虎 院 （系）： 电 子 工 程 学 院 专业班级 ： 测控 0703 班 指导教师 ： 贾惠芹 完成日期 ： 2020 年 3 月 5 日 16 Expanding the Features of a VI You can choose one of many LabVIEW VI templates to use as a starting point. However, sometimes you need to build a VI for which a template is not available. This chapter teaches you how to build and customize a VI without using a template. Building a VI from a Blank Template In the following exercises, you will open a blank VI and add Express VIs and structures to theblock diagram to build a new VI. You will build a VI that generates a signal, reduces the number of samples in the signal, and displays the resulting data in a table on the front panel. When you plete the exercises, the front panel of the VI will look similar to the front panel in Figure 31. You can plete the exercises in approximately 30 minutes. Figure 31. Front Panel for the Reduce Samples VI Opening a Blank VI If no template is available for the task you want to create, you can start with a blank VI and add Express VIs to acplish the specific task. Complete the following steps to open a blank VI. 1. In the LabVIEW dialog box, click the arrow on the New button and select BlankVI from the shortcut menu or press the CtrlN keys to open a blank VI. Notice that a blank front panel and block diagram appear. 17 Note You also can open a blank VI by selecting Blank VI from the Create new list in The New dialog box or by selecting File187。 New VI from the front panel or block diagram menu bar. 2. If the Functions palette is not visible, rightclick any blank space on the block diagram to bring up the temporary version of the Functions palette. Click the thumbtack, shown at left, in the upper left corner of the Functions palette to place the palette on the screen. Note You can rightclick on a blank space on the block diagram or the front panel to bring up the Functions or Controls palettes. Adding an Express VI that Simulates a Signal Complete the following steps to find the Express VI you want to use and then add it to the block diagram. 1. If the Context Help window is not visible, press the CtrlH keys to open the Context Help window. You also can press the Show Context Help Window button, shown at left, to open the Context Help window. 2. Select the Input palette on the Functions palette and move the cursor over the Express VIs on the Input that the Context Help window displays information about the function of each Express VI. 3. From the information provided in the Context Help window, find theExpress VI that can output a sine wave signal. 4. Select the Express VI and place it on the block diagram. The Configure Simulate Signal dialog box appears. 5. Idle the cursor over the various options in the Configure Simulate Signal dialog box, such as Frequency (Hz), Amplitude, and Samples per second (Hz). Read the information that appears in the Context Help window. 6. Configure the Simulate Signal Express VI to generate a sine wave with a frequency of and amplitude of 2. 7. Notice how the signal displayed in the Result Preview window changes to reflect the configured sine wave. 8. Close the Configure Simulate Signal dialog box. 18 9. Move the cursor over the Simulate Signal Express VI and read the information that appears in the Context Help that the Context Help window now displays the configuration of the Simulate Signal Express VI. 10. Save this VI as Reduce to an easily accessible location. Modifying the Signal Complete the following steps to use the LabVIEW Help to search for the Express VI that reduces the number of samples in a signal. 1. Select Help187。 VI, Function, amp。 HowTo Help to open the LabVIEW Help. 2. Click the Search tab and type sample pression in the Type in the word(s) to search for text box. Notice that this word choice reflects what you want this Express VI to do— press, or reduce, the number of samples in a signal. 3. Select the Sample Compression Express VI topic to display the topic th。