the ability to use a simple data display from the System set. Once you have dragged a control or indicator onto the front panel, the pop-up menu can be used to modify its attributes. The type (floating point, integer, unsigned, or complex), data range, format, and representation are typical attributes for a digital control. Representation types that can be displayed for users are decimal, hexadec- imal, date/time, and engineering notation. Representation types do not alter the numbers stored in memory; for example, displaying two digits beyond the decimal point does not cause LabVIEW to truncate numbers internally.
Figure 1.11 displays the window that appears when Format & Precision is selected from the pop-up menu. The Numeric Properties pop-up window contains several tabs. The appearance tab contains control configuration properties such as the label and caption visible on the display. The Data Range tab is of importance; it configures the default control value and allows the control to have its valid range of inputs configured. Data validation is critical in any application that is geared towards quality and we strongly encourage all programmers to use this functionality. Data entered outside the minimum and maximum range values can be either coerced to the range or ignored. This functionality does not work if the VI is called as a subVI. In the coercion case, the input data is set to the minimum or maximum range. The control can also be configured to ignore the entry. If the data range functionality is not used, the application should validate ranges in the application itself. The format and precision tab affects the display of the data, but not the internal value. The type ranges will determine how data is presented in the control. Internally numerical values are not truncated or rounded when settings in this tab are selected. Floating point data can be shown in various formats, such as truncating the number of digits displayed and integer data can be displayed in decimal, hexadecimal, octal, or binary formats. Nondecimal displays are commonly used and convenient when it comes to data such as fields in communications protocols.The nondigital objects in the numeric palette have an option to display a digital value with them through the pop-up menu. Just select the Visible Items in the popup menu and then select Digital Display from the .submenu. Figure 1.12 shows the meter with its associated digital indicator for precise readings. The meter, as most controls, can be resized by dragging one of the corners. The scale, markers, and mapping can also be modified on the meter.
1.6.1.2 Boolean
The Boolean palettes for the modern and classic palettes are illustrated in Figure 1.13. These palettes contain various true or false controls and indicators. Buttons to replicate switches, LED indicators, and operating system OK and Cancel buttons are provided. It is unlikely programmers will come up with Boolean indicator requirements that are not captured somewhere in this palette. Some of the controls in this palette are also available in the Dialog palette.。
LabVIEW简介
程序员不断的开发应用软件都是为了在各种情况下提高生产力的效率。LabVIEW,作为一种编程语言论文网,是一种功能很强的的工具,可以用来帮助实现这些目标。 LabVIEW(实验室虚拟仪器工程工作台)是由NI公司开发的一种基于图形化编程的语言。其图形的性质,使得它非常适合测试与测量(T&M),自动化,仪器控制,数据采集,数据分析的应用。相比传统的编程语言它显著提高了生产力。美国国家仪器公司把重点放在测试与测量上,这给了他们在发展LabVIEW上一个很好的视野。
本章将提供一个LabVIEW的简要介绍。一些基本的主题会让你对于LabVIEW如何工作和如何使用它有个更好的了解。本章节的目的不是要让初学者彻底学会LabVIEW编程。那些希望学习应用LabVIEW的人应考虑参加一个美国国家仪器公司的LabVIEW基础课程。有关信息资料课程,时间表,和地点在www.ni.com/training能找到。如果你有了相关的经验,你可以跳过这个章节,开始后面的章节。首先我们将讨论VI及其组件,其次是LabVIEW的数据流编程方式。然后-源+自=751&文/论|文]网[www.751com.cn,几个有关创建的VI的主题以及解释前面板和框图。本章将总结图标的说明和设置的选项。 LabVIEW简介英文文献和中文翻译(7):http://www.751com.cn/fanyi/lunwen_51997.html