虛擬儀器外文翻譯

1、<p><b>　　LabVIEW</b></p><p>　　1．overview</p><p>　　LabVIEW is a program development environment, by the national instruments (NI) research and development company, similar to the

2、 C and BASIC development environment, but with other computer language LabVIEW significant difference is: other computer language is based on the text, and the language code of graphical LabVIEW use scripting language G

3、program, application is in the form of block diagram.</p><p>　　A complete, LabVIEW virtual instrument system of open application software development, and use it to form instrument testing system and data co

4、llecting system can simplify the design procedure. With Visual C++ LabVIEW, Visual Basic,LabWindows/CVI, etc, which adopts different programming language is based on the text language program Code (Code), and abVIEW L is

5、 using graphical programming language), Graphic (G instead of the traditional diagram of the Code. The Lab VIEW of equipment with the sc</p><p>　　LabVIEW convenient calls Windows DLL and user-defined functio

6、n in the DLL, LabVIEW also provides CIN (C) Node with any users can use by C + + language or, if the ANSI C, compiled program modules, makes a open LabVIEW development platform. LabVIEW also directly support dynamic data

7、 exchange (DDE), structured query language (SQL), TCP and UDP network protocol. In addition, the LabVIEW also provides special used for program development kit, users can easily set breakpoints, dynamic program executio&

8、lt;/p><p>　　The operation mechanism is LabVIEW macroeconomic sense is no longer the von neumann traditionally computer system structure of the method. The traditional computer language (such as C) to the order

9、of execution by parallel structure in LabVIEW mechanism; Essentially, it is a kind of control Flow structure with graphical Data Flow pattern (Data Flow Mode), this kind of means to ensure the process of any Node Functio

10、n in hire those knowledgeable programmers only after all it can only be executed D</p><p>　　That is to say, in the data flow in the concept of program execution, and it is the data driven by operating system

11、, calculate machine and so on.</p><p>　　Since LabVIEW program is data flow driven, data flow design program, a goal only when it's all input can only be effective, And the goal of output only when it is

12、complete. So, in VIEW of the Lab is connected the data flow between nodes function control program execution sequence, and don't like text program execution sequence by rows of constraint. Thus, we can be connected t

13、hrough the rapid development of concise function node applications, even can have multiple data synchronization operation</p><p>　　2．Data Storage and Reporting with NI LabVIEW</p><p>　　The conti

14、nued increase in processing and storage capacity and the decrease of hardware and software costs has resulted in an explosion of collected data being acquired. But while technology is enabling faster and richer data rete

15、ntion, storing, managing, and sharing data remains the real challenge. Traditional software packages tend to take one of two limiting approaches: 1) they force you into a particular format that is not exchangeable with o

16、ther applications or users or 2) saving data is lef</p><p>　　NI LabVIEW, designed for the entire engineering process, includes built-in functionality to help you easily save data to disk and create professio

17、nal reports. By providing easy yet robust interfaces for file I/O and reporting, you can make the most of your acquired data to make decisions faster. </p><p>　　(1)File I/O Designed Specifically for Engineer

18、ing Data </p><p>　　Despite the fact that LabVIEW offers a wide variety of file I/O options, these traditional file types rarely meet all the criteria you need in a file format. For example, ASCII files are e

19、xchangeable, but are very large and slow to read and write. On the other hand, binary file read and write speeds can keep up with high-speed hardware, but are difficult to share with others.</p><p>　　Because

20、 of the drawbacks of traditional  file I/O, National Instruments developed the Technical Data Management Streaming (TDMS) file format to meet the specific needs and high demands of engineers and scientists. TDMS fil

21、es are based on the TDM data model for saving well-organized and documented test and measurement data. The TDM data model offers three levels of hierarchy, as shown in Figure 2 – file, group, and channel. The file level

22、can contain an unlimited number of groups, and each group </p><p>　　Figure 1. The TDM data model meets the specific requirements of measurement data.</p><p>　　Also, you can insert your own custo

23、m properties at each of the three levels. Each level accepts an unlimited number of custom-defined attributes to achieve well-documented and search-ready data files. The descriptive information located in the TDMS file,

24、a key benefit of this model, provides an easy way to document the data much like you would document code. As your documentation requirements increase, you do not have to redesign your application, you simply extend the d

25、ata model to meet your ne</p><p>　　(2)Multiple Easy-to-Use Programming Interfaces </p><p>　　Because it was developed to meet the needs of all engineers, TDMS offers ease of use, high-speed strea

26、ming, and exchangeability. Like many operations in LabVIEW, you can use multiple interfaces to write TDMS files. You can quickly read and write TDMS files using a virtual instrument (VI) such as the Write To Measurement

27、File Express VI or, for the best performance and customization, use the primitive TDMS VIs from the File I/O palette. Also, when using LabVIEW with NI-DAQmx, you can use the Conf</p><p>　　(3)Files Exchangeab

28、le with Other Programs such as Microsoft Excel </p><p>　　Because you may be required to work in additional applications, TDMS is easily exchangeable across other programs. You can open TDMS files in Microsof

29、t Excel using the TDM Excel Add-In, which installs with NI software and is available free at ni.com. You also can use a C DLL for reading and writing TDMS files in other programming languages. NI is committed to helping

30、you write well-organized and documented data using the TDMS file format, regardless of which products you use.</p><p>　　(4)Custom and Legacy File Format Reading and Writing </p><p>　　Although id

31、eally you can choose the file format for each application you work on, you may still be restricted to reading and writing in a custom format due to legacy files or hardware that uses custom formats. Understanding that ma

32、ny engineers face this challenge, NI developed the DataPlugin technology so that you can use these custom formats in LabVIEW. As seen in Figure 4, a DataPlugin acts as a file parser that tells LabVIEW and other NI softwa

33、re how to read your custom file formats and maps </p><p>　　Figure 2. Using a DataPlugin, you can map any file format onto the TDM data model.</p><p>　　National Instruments provides more than 200

34、 free, downloadable DataPlugins for the most common file formats. For custom formats, you can create your own DataPlugins in LabVIEW and NI DIAdem software using a documented API, or request that an NI expert create a Da

35、taPlugin for you. Using DataPlugins, you are no longer limited by custom formats and applications, and have options for how to use your data. </p><p>　　3．Organizing and Managing Your Data with DataFinder Tec

36、hnology </p><p>　　With many applications, the amount of data being collected can quickly become overwhelming. Typically, at that point, you might turn to a database to begin storing your data for faster sear

37、ch and trending. National Instruments makes it easy to interact with a database using the LabVIEW Database Connectivity Toolkit by abstracting the low-level structured query language (SQL) queries. However, moving your e

38、xisting data to a database, maintaining the database, and creating applications for accessi</p><p>　　In response to this challenge, NI developed NI DataFinder technology, included in the LabVIEW DataFinder T

39、oolkit and DIAdem, for managing test files without the headache and expense of setting up and maintaining a large database. With NI DataFinder, you can perform Internet-like searches across all your data files, regardles

40、s of format and location within your company intranet. Simply point NI DataFinder to the location of your data files, and within seconds you can search for your files just as</p><p>　　NI DataFinder automatic

41、ally builds and maintains an index of all files that meet the file type and location criteria in the NI DataFinder configuration. You can use properties automatically stored in the NI DataFinder index in query conditions

42、. When a valid data file is created, deleted, or edited, NI DataFinder automatically notices and reindexes the hierarchy and properties of the file. When you save properties not yet in NI DataFinder in a newly created fi

43、le, these properties are automaticall</p><p>　　4.Multiple Programming Approaches in NI LabVIEW</p><p>　　NI LabVIEW is a graphical dataflow programming environment. When using dataflow in LabVIEW

44、, you define an execution flow in code by creating diagrams that show how data moves between functions (known as virtual instruments, or VIs). However, with LabVIEW, you can combine multiple programming approaches beside

45、s graphical data flow (G) in a single application. Use this flexibility to select your tool of choice for creating algorithms and solving an infinite variety of engineering problems. </p><p>　　(1)Defining Pr

46、ogramming Approaches </p><p>　　The phrase ‘programming approaches’ encompasses different languages for programming, models of computation, levels of abstraction, methods for interacting with existing code, a

47、nd ways for representing algorithms. Over the years, National Instruments has added interfaces and methods for communication in LabVIEW to extend the number of approaches that are available.You can write and import multi

48、ple approaches into the same block diagram as the familiar G dataflow language. LabVIEW compiles all of </p><p>　　(2)Programming in G </p><p>　　Data flow, the fundamental LabVIEW programming met

49、hod, was the original, and only, programming approach when NI introduced LabVIEW 1.0 in 1986. Unlike sequential-style programming, the flow of data in a dataflow program dictates when, and in what order, operations are e

50、xecuted. In sequential languages such as C and C++, the order of the commands in the source code (as opposed to the availability of data) determines the order in which execution will occur.</p><p>　　G follow

51、s a dataflow model for running functions and primitives, or VIs. A block diagram function or node executes when all its inputs are available. When a node completes execution, it supplies data to its output terminals and

52、passes the output data to the next node in the dataflow path.</p><p>　　Figure 3. A and B are added, and the result is multiplied by C and displayed.</p><p>　　The graphical code in Figure 2 show

53、s how a mathematical equation can be represented in G. This diagram consists of two nodes (an add node and a multiply node), and has three numerical inputs (A, B, and C). First, A and B are added. The multiplication node

54、 does not execute until both inputs are provided, so it depends on the addition node to complete and provide the result of A + B, at which point it computes the result – (A+B)*C.</p><p>　　Although it is poss

55、ible to explicitly define variables in G, one of the most obvious differences between G code and other languages is that the functional equivalent of a traditional variable is a wire. Instead of passing variables between

56、 functions, wires define the functions to which a value is passed. Other familiar programming concepts such as While Loops, For Loops, conditional code, callback functions, and digital logic are all part of the G dataflo

57、w programming language</p><p>　　(3)Using Configuration-Based Programming </p><p>　　In 2003, National Instruments released NI LabVIEW 7 Express, which featured Express VIs – a new technology desi

58、gned to further simplify common programming tasks and algorithm creation. Unlike traditional VIs, Express VIs abstracted tasks by offering a configuration-based approach to programming.</p><p>　　LabVIEW dist

59、inguishes Express VIs with large blue icons. When you place an Express VI on the block diagram, a dialog appears so you can configure how the function executes. After completing the configuration, the LabVIEW development

60、 environment writes the necessary code (represented by the Express VI) for you. You can view and modify this code, and you can change the Express VI configuration by simply double-clicking the Express VI icon.</p>

61、<p>　　Consider the task of reading real-world signals into software for analysis. LabVIEW is designed to make integration with hardware for I/O simple and easy thanks to native drivers and support for thousands of

62、instruments. However, even a task that would otherwise take a handful of VIs to execute can be simplified to a single Express VI. The DAQ Assistance Express VI prompts you to select the channels you want to send and rece

63、ive I/O to and from, and configure parameters such as sample rate, termi</p><p>　　Express VIs do not offer the same low-level control as VIs, which is why you may prefer to write the code entirely using VIs.

64、 New users interested in learning low-level constructs can easily convert an Express VI to the underlying G code by right-clicking the Express VI and selecting Open Front Panel. Normal VIs can do everything an Express VI

65、 can do. The LabVIEW Professional Development System also includes a utility for creating custom Express VIs.</p><p>　　(4)Incorporating C-Based Syntax </p><p>　　We can incorporate sequentially e

66、xecuted text-based syntax into a VI block diagram using one of several techniques. The Formula Node offers an inline structure that supports a syntax similar to traditional C programming. Much like C, every line ends wit

67、h a semicolon and variables must have a defined scope.</p><p>　　The Inline C Node is similar to the Formula Node with additional support and functionality for low-level programming and header files without t

68、he overhead of a function call. You can use the Inline C Node for any C code, including assembly directives and #defines, that syntactically is between the curly braces in a C file.</p><p>　　The Inline C Nod

69、e is available only for targets that use generated C code. The Inline C Node is not supported for desktop Windows targets.</p><p>　　(5)Interfacing with Built Assemblies </p><p>　　Instead of impo

70、rting source code to a LabVIEW block diagram, you may want to call into built assemblies or reuse built LabVIEW applications in other environments. Applications written in LabVIEW can easily reuse existing code and algor

71、ithms developed in other languages or programming approaches. Additionally, you might need to build an assembly from LabVIEW code, which includes the programming approaches discussed above, to be called by a different en

72、vironment.</p><p>　　LabVIEW offers multiple solutions for both scenarios. LabVIEW can call external code in DLLs or shared libraries and code exposed through ActiveX or .NET interfaces. In addition, you can

73、reuse LabVIEW code in other programming languages by building a LabVIEW DLL or shared library, or by using ActiveX.</p><p>　　If you have existing C code and need to reuse it in LabVIEW, one technique is to b

74、uild the code as a DLL and call it using the Call Library Function Node. In fact, based on your C application architecture, you can use simple LabVIEW parallel programming to run two or more existing C routines in parall

75、el without the additional complexity of C-based multithreaded programming. To make importing external libraries simple, LabVIEW includes the Import Shared Library Wizard, which automatically creates</p><p>　

76、　Interfacing with the command-line is also possible with the System Exec.vi, which provides OS-specific interfaces for calling executables and other build libraries. </p><p>　　(6)aking Advantage of Flexible

77、Programming </p><p>　　The combination of multiple programming approaches in a single development environment offers the advantage of reusing existing code and algorithms developed in other languages. It also

78、 makes it possible to combine simple, high-level abstractions with lower-level code that gives you more visibility and control of your application. These abstraction layers represent highly complex operations in simple,

79、easy-to-read representations, but can be coupled with functions that give low-level control ove</p><p>　　5．The Benefits of Programming Graphically in NI LabVIEW</p><p>　　Graphical program design

80、 and programming simple, intuitive, and development of high efficiency. With the continuous development of the virtual instrument technology and graphical programming language test and control will become the most promis

81、ing field development direction.</p><p>　　Graphical programming language, which is also known as "G" language. Use this kind of language programming, basically don't write code, instead of char

82、t or diagram. It was possible use technical personnel, scientists, engineers, familiar terminology and concepts, therefore, ICONS, LabVIEW is a tool for end users. It can enhance your own science and engineering construc

83、tion, provides realizing instrument programming and convenient way of data acquisition system. Use it to research, design, testin</p><p>　　(1)abVIEW: Graphical, Dataflow Programming </p><p>　　La

84、bVIEW is different from most other general-purpose programming languages in two major ways. First, G programming is performed by wiring together graphical icons on a diagram, which is then compiled directly to machine co

85、de so the computer processors can execute it. While represented graphically instead of with text, G contains the same programming concepts found in most traditional languages. For example, G includes all the standard con

86、structs, such as data types, loops, event handling, variab</p><p>　　The second main differentiator is that G code developed with LabVIEW executes according to the rules of data flow instead of the more tradi

87、tional procedural approach (in other words, a sequential series of commands to be carried out) found in most text-based programming languages like C and C++. Dataflow languages like G (as well as Agilent VEE, Microsoft V

88、isual Programming Language, and Apple Quartz Composer) promote data as the main concept behind any program. Dataflow execution is data-driven</p><p>　　This distinction may seem minor at first, but the impact

89、 is extraordinary because it renders the data paths between parts of the program to be the developer’s main focus. Nodes in a LabVIEW program (in other words, functions, structures such as loops, subroutines, and so on)

90、have inputs, process data, and produce outputs. Once all of a given node’s inputs contain valid data, that node executes its logic, produces output data, and passes that data to the next node in the dataflow path. A node

91、 tha</p><p>　　(2)ntuitive Graphical Programming </p><p>　　Like most people, engineers and scientists learn by seeing and processing images without any need for conscious contemplation. Many engi

92、neers and scientists can also be characterized as “visual thinkers,” meaning that they are especially adept at using visual processing to organize information. In other words, they think best in pictures. This is often r

93、einforced in colleges and universities, where students are encouraged to model solutions to problems as process diagrams. However, most general-</p><p>　　Figure 4. Data originates in the acquisition function

94、 and then flows intuitively to the analysis and storage functions through wires. </p><p>　　(3)utomatic Parallelism and Performance </p><p>　　Dataflow languages like LabVIEW allow for automatic p

95、arallelization. In contrast to sequential languages like C and C++, graphical programs inherently contain information about which parts of the code should execute in parallel. For example, a common G design pattern is th

96、e Producer/Consumer Design Pattern, in which two separate While Loops execute independently: the first loop is responsible for producing data and the second loop processes data. Despite executing in parallel (possibly at

97、 differ</p><p>　　Parallelism is important in computer programs because it can unlock performance gains relative to purely sequential programs due to recent changes in computer processor designs. For more tha

98、n 40 years, computer chip manufacturers increased processor clock speed to increase chip performance. Today, however, increasing clock speeds for performance gains is no longer viable because of power consumption and hea