|This article may rely excessively on sources too closely associated with the subject, potentially preventing the article from being verifiable and neutral. (May 2015)|
The graphical language is named "G" (not to be confused with G-code). Originally released for the Apple Macintosh in 1986, LabVIEW is commonly used for data acquisition, instrument control, and industrial automation on a variety of platforms including Microsoft Windows, various versions of UNIX, Linux, and Mac OS X. The latest version of LabVIEW is LabVIEW 2014, released in August 2014.
- 1 Dataflow programming
- 2 Graphical programming
- 3 Benefits
- 4 Criticism
- 5 Timing system
- 6 Release history
- 7 Repositories and libraries
- 8 Related software
- 9 See also
- 10 References
- 11 Further reading
- 12 External links
The programming language used in LabVIEW, also referred to as G, is a dataflow programming language. Execution is determined by the structure of a graphical block diagram (the LabVIEW-source code) on which the programmer connects different function-nodes by drawing wires. These wires propagate variables and any node can execute as soon as all its input data become available. Since this might be the case for multiple nodes simultaneously, G is inherently capable of parallel execution. Multi-processing and multi-threading hardware is automatically exploited by the built-in scheduler, which multiplexes multiple OS threads over the nodes ready for execution.
LabVIEW ties the creation of user interfaces (called front panels) into the development cycle. LabVIEW programs/subroutines are called virtual instruments (VIs). Each VI has three components: a block diagram, a front panel and a connector panel. The last is used to represent the VI in the block diagrams of other, calling VIs. The front panel is built using controls and indicators. Controls are inputs – they allow a user to supply information to the VI. Indicators are outputs – they indicate, or display, the results based on the inputs given to the VI. The back panel, which is a block diagram, contains the graphical source code. All of the objects placed on the front panel will appear on the back panel as terminals. The back panel also contains structures and functions which perform operations on controls and supply data to indicators. The structures and functions are found on the Functions palette and can be placed on the back panel. Collectively controls, indicators, structures and functions will be referred to as nodes. Nodes are connected to one another using wires – e.g. two controls and an indicator can be wired to the addition function so that the indicator displays the sum of the two controls. Thus a virtual instrument can either be run as a program, with the front panel serving as a user interface, or, when dropped as a node onto the block diagram, the front panel defines the inputs and outputs for the node through the connector pane. This implies each VI can be easily tested before being embedded as a subroutine into a larger program.
The graphical approach also allows non-programmers to build programs by dragging and dropping virtual representations of lab equipment with which they are already familiar. The LabVIEW programming environment, with the included examples and documentation, makes it simple to create small applications. This is a benefit on one side, but there is also a certain danger of underestimating the expertise needed for high-quality G programming. For complex algorithms or large-scale code, it is important that the programmer possess an extensive knowledge of the special LabVIEW syntax and the topology of its memory management. The most advanced LabVIEW development systems offer the possibility of building stand-alone applications. Furthermore, it is possible to create distributed applications, which communicate by a client/server scheme, and are therefore easier to implement due to the inherently parallel nature of G.
Interfacing to Devices
LabVIEW includes extensive support for interfacing to devices, instruments, cameras, and other devices. Users interface to hardware by either writing direct bus commands (USB, GPIB, Serial) or using high-level, device-specific, drivers that provide native LabVIEW function nodes for controlling the device.
LabVIEW includes built-in support for NI hardware platforms such as CompactDAQ and CompactRIO, with a large number of device-specific blocks for such hardware, the Measurement and Automation eXplorer (MAX) and Virtual Instrument Software Architecture (VISA) toolsets.
National Instruments makes thousands of device drivers available for download on the NI Instrument Driver Network (IDNet).
In terms of performance, LabVIEW includes a compiler that produces native code for the CPU platform. The graphical code is translated into executable machine code by interpreting the syntax and by compilation. The LabVIEW syntax is strictly enforced during the editing process and compiled into the executable machine code when requested to run or upon saving. In the latter case, the executable and the source code are merged into a single file. The executable runs with the help of the LabVIEW run-time engine, which contains some precompiled code to perform common tasks that are defined by the G language. The run-time engine reduces compile time and also provides a consistent interface to various operating systems, graphic systems, hardware components, etc. The run-time environment makes the code portable across platforms. Generally, LabVIEW code can be slower than equivalent compiled C code, although the differences often lie more with program optimization than inherent execution speed.
Many libraries with a large number of functions for data acquisition, signal generation, mathematics, statistics, signal conditioning, analysis, etc., along with numerous graphical interface elements are provided in several LabVIEW package options. The number of advanced mathematic blocks for functions such as integration, filters, and other specialized capabilities usually associated with data capture from hardware sensors is immense. In addition, LabVIEW includes a text-based programming component called MathScript with additional functionality for signal processing, analysis and mathematics. MathScript can be integrated with graphical programming using "script nodes" and uses a syntax that is generally compatible with MATLAB.
LabVIEW is an inherently concurrent language, so it is very easy to program multiple tasks that are performed in parallel by means of multithreading. This is, for instance, easily done by drawing two or more parallel while loops. This is a great benefit for test system automation, where it is common practice to run processes like test sequencing, data recording, and hardware interfacing in parallel.
Due to the longevity and popularity of the LabVIEW language, and the ability for users to extend the functionality, a large ecosystem of 3rd party add-ons has developed through contributions from the community. This ecosystem is available on the LabVIEW Tools Network, which is a marketplace for both free and paid LabVIEW add-ons.
There is a low-cost LabVIEW Student Edition aimed at educational institutions for learning purposes. There is also an active community of LabVIEW users who communicate through several e-mail groups and Internet forums.
LabVIEW is a proprietary product of National Instruments. Unlike common programming languages such as C or FORTRAN, LabVIEW is not managed or specified by a third party standards committee such as ANSI, IEEE, ISO, etc.
Data Flow Programming Model
Due to its thorough adoption of a data-flow programming model as opposed to the sequential ordering of arbitrary commands like most other (usually text-based) languages there is a very real barrier to many people who attempt to apply already-learned principles from other programming approaches to LabVIEW. The inherent parallel nature of the execution of LabVIEW code is a perennial source of confusion among those who are accustomed to other approaches. Due to this, most opinions tend to be highly polarised with people either being extremely fond of it or being extremely hostile to it.
Building a stand-alone application with LabVIEW requires the Application Builder component which is included with the Professional Development System but requires a separate purchase if using the Base Package or Full Development System.
Compiled executables produced by version 6.0 and later of the Application Builder are not truly standalone in that they also require the LabVIEW run-time engine be installed on any target computer which runs the application. The use of standard controls requires a run-time library for any language. All major operating systems supply the required libraries for common languages such as C. However, the run-time required for LabVIEW is not supplied with any operating system and has to be specifically installed by the administrator or user. This can cause problems if an application is distributed to a user who may be prepared to run the application but does not have the inclination or permission to install additional files on the host system prior to running the executable.
Race conditions and pseudo parallel execution
The G gives the impression of being a parallel language (such as VHDL) that has modules that run in parallel, however, it is essentially implemented on a non parallel platform without explicit race condition control. This greatly simplifies programming on multi-core and multi-processor systems, as long as the user takes care of the race conditions.
LabVIEW makes it difficult to get machine or hardware limited performance and tends to produce applications that are slower than hand coded native languages such as C. High performance can be achieved while using multi-core machines or dedicated toolkits for specific operations. LabVIEW makes multi-core programming much simpler and faster than text based languages.
Light weight applications
Very small applications still have to start the runtime environment which is a large and slow task. This makes writing and running small applications or applications that might run in parallel on the same platform problematic and tends to restrict LabVIEW to monolithic applications. Examples of this might be tiny programs to grab a single value from some hardware that can be used in a scripting language - the overheads of the runtime environment render this approach impractical with LabVIEW.
Starting with LabVIEW 8.0, major releases are released around the first week of August, to coincide with the annual National Instruments conference NI Week; followed by a bug-fix release the following February. In 2009 National Instruments names the releases after the year in which they are released. The bug-fix is called a Service Pack (for instance the 2009 service pack 1 is released in February 2010).
|LabVIEW project begins||April 1983|
|LabVIEW 1.0 (for Macintosh)||??||October 1986|
|LabVIEW 2.0||??||January 1990|
|LabVIEW 2.5 (first release for Sun & Windows)||??||August 1992|
|LabVIEW 3.0 (Multiplatform)||??||July 1993|
|LabVIEW 3.0.1 (first release for Windows NT)||??||1994|
|LabVIEW 3.1.1 (first release with "application builder" capability)||??||1995|
|LabVIEW 4.0||??||April 1996|
|LabVIEW 5.0||??||February 1998|
|LabVIEW RT (Real Time)||??||May 1999|
|LabVIEW 6.0 (6i)||126.96.36.19905||26 July 2000|
|LabVIEW 6.1||188.8.131.5204||12 April 2001|
|LabVIEW 7.0 (Express)||184.108.40.20600||April 2003|
|LabVIEW PDA module first released||??||May 2003|
|LabVIEW FPGA module first released||??||June 2003|
|LabVIEW Embedded module first released||??||May 2005|
|LabVIEW 8.0||220.127.116.1105||September 2005|
|LabVIEW 8.20 (native Object Oriented Programming)||??||August 2006|
|LabVIEW 8.2.1||18.104.22.16802||21 February 2007|
|LabVIEW 8.6||22.214.171.12401||24 July 2008|
|LabVIEW 8.6.1||126.96.36.19901||10 December 2008|
|LabVIEW 2009 (32 and 64-bit)||188.8.131.5222||4 August 2009|
|LabVIEW 2009 SP1||184.108.40.20611||8 January 2010|
|LabVIEW 2010||10.0.0.4032||4 August 2010|
|LabVIEW 2010 f2||10.0.0.4033||16 September 2010|
|LabVIEW 2010 SP1||10.0.1.4004||17 May 2011|
|LabVIEW for LEGO MINDSTORMS (2010 SP1 with some modules)||August 2011|
|LabVIEW 2011||220.127.116.1129||22 June 2011|
|LabVIEW 2011 SP1||18.104.22.16815||1 March 2012|
|LabVIEW 2012||22.214.171.12429||August 2012|
|LabVIEW 2012 SP1||126.96.36.19913||December 2012|
|LabVIEW 2013||188.8.131.5247||August 2013|
|LabVIEW 2013 SP1||184.108.40.20617||March 2014|
|LabVIEW 2014||August 2014|
|LabVIEW 2014 SP1||220.127.116.1108||March 2015|
Repositories and libraries
OpenG, as well as LAVA Code Repository (LAVAcr), serve as repositories for a wide range of Open Source LabVIEW applications and libraries. SourceForge has LabVIEW listed as one of the possible languages in which code can be written.
VI Package Manager has become the standard package manager for LabVIEW libraries. It is very similar in purpose to Ruby's RubyGems and Perl's CPAN, although it provides a graphical user interface similar to the Synaptic Package Manager. VI Package Manager provides access to a repository of the OpenG (and other) libraries for LabVIEW.
National Instruments also offers a product called Measurement Studio, which offers many of the test, measurement and control capabilities of LabVIEW, as a set of classes for use with Microsoft Visual Studio. This allows developers to harness some of LabVIEW's strengths within the text-based .NET framework. National Instruments also offers LabWindows/CVI as an alternative for ANSI C programmers.
When applications require sequencing, users often use LabVIEW with TestStand test management software, also from National Instruments.
The TRIL Centre Ireland BioMobius platform and DSP Robotics' FlowStone DSP also use a form of graphical programming similar to LabVIEW, but are limited to the biomedical and robotics industries respectively.
LabVIEW has a direct node with modeFRONTIER, a multidisciplinary and multi-objective optimization and design environment, written to allow coupling to almost any computer-aided engineering tool. Both can be part of the same process workflow description and can be virtually driven by the optimization technologies available in modeFRONTIER.
- Comparison of numerical analysis software
- Dataflow programming
- Fourth-generation programming language
- Graphical programming
- Graphical system design
- Lego Mindstorms NXT, whose programming environment, NXT-G is based on LabVIEW, and can be programmed within LabVIEW.
- Virtual instrumentation
- NI Instrument Driver Network
- "Building a Stand-Alone Application". National Instruments.
- "Using the LabVIEW Run-Time Engine". National Instruments.
- Spolsky, Joel. "Why are the Microsoft Office file formats so complicated? (And some workarounds)". Retrieved March 8, 2009.
- Embedding a C/C++ Interpreter Ch into LabVIEW for Scripting
- Peter A. Blume: The LabVIEW Style Book, February 27, 2007, Prentice Hall. Part of the National Instruments Virtual Instrumentation Series series. ISBN 0-13-145835-3
- Jeffrey Travis, Jim Kring: LabVIEW for Everyone: Graphical Programming Made Easy and Fun, 3rd Edition, July 27, 2006, Prentice Hall. Part of the National Instruments Virtual Instrumentation Series. ISBN 0-13-185672-3
Articles on specific uses
- Desnica V, Schreiner M, Vladan; Schreiner, Manfred (October 2006). "A LabVIEW-controlled portable x-ray fluorescence spectrometer for the analysis of art objects". X-Ray Spectrometry 35 (5): 280–286. doi:10.1002/xrs.906.
- Keleshis C, Ionita C, Rudin S, C; Ionita, C; Rudin, S (June 2006). "Labview [sic] graphical user interface for micro angio-fluoroscopic high resolution detector". Medical Physics 33 (6): 2007. doi:10.1118/1.2240285.
- Fedak W, Bord D, Smith C, Gawrych D, Lindeman K, W.; Bord, D.; Smith, C.; Gawrych, D.; Lindeman, K. (May 2003). "Automation of the Franck-Hertz experiment and the Tel-X-Ometer x-ray machine using LABVIEW". American Journal of Physics (AAPT) 71 (5): 501–506. doi:10.1119/1.1527949.
Articles on education uses
- Belletti A, Borromei R, Ingletto G, A.; Borromei, R.; Ingletto, G. (September 2006). "Teaching physical chemistry experiments with a computer simulation by LabVIEW". Journal of Chemical Education (ACS) 83 (9): 1353–1355. doi:10.1021/ed083p1353.
- Moriarty PJ, Gallagher BL, Mellor CJ, Baines RR, P. J.; Gallagher, B. L.; Mellor, C. J.; Baines, R. R. (October 2003). "Graphical computing in the undergraduate laboratory: Teaching and interfacing with LabVIEW". American Journal of Physics (AAPT) 71 (10): 1062–1074. doi:10.1119/1.1582189.
- Lauterburg, Urs (June 2001). "LabVIEW in Physics Education" (PDF). A white paper about using LabVIEW in physics demonstration and laboratory experiments and simulations.
- Drew SM, Steven M. (December 1996). "Integration of National Instruments' LabVIEW software into the chemistry curriculum". Journal of Chemical Education (ACS) 73 (12): 1107–1111. doi:10.1021/ed073p1107.
- Muyskens MA, Glass SV, Wietsma TW, Gray TM, Mark A.; Glass, Samuel V.; Wietsma, Thomas W.; Gray, Terry M. (December 1996). "Data acquisition in the chemistry laboratory using LabVIEW software". Journal of Chemical Education (ACS) 73 (12): 1112–1114. doi:10.1021/ed073p1112.
- Ogren PJ, Jones TP, Paul J.; Jones, Thomas P. (December 1996). "Laboratory interfacing using the LabVIEW software package". Journal of Chemical Education (ACS) 73 (12): 1115–1116. doi:10.1021/ed073p1115.
- Trevelyan, J.P. (June 2004). "10 Years Experience with Remote Laboratories" (PDF). International Conference on Engineering Education Research (ACS).
- Official Home Page - The National Instruments web site for the LabVIEW product line.
- LabVIEW Tools Network - Ecosystem of LabVIEW Add-on products, contributed by NI and the community.
- LabVIEW Help - NI's entire set of online help documentation for LabVIEW 2012.
- LabVIEW Help - NI's entire set of online help documentation for LabVIEW 2010.
- LabVIEW Help - NI's entire set of online help documentation for LabVIEW 2009.
- LabVIEW Help - NI's entire set of online help documentation for LabVIEW 8.5.
- LabVIEW Help - NI's entire set of online help documentation for LabVIEW 8.20.
- Official LabVIEW Community Home Page - NI's "LabVIEW Zone" web site.
- LAVA (LabVIEW Advanced Virtual Architects) - Independent community, with discussion forums and a code repository.
- Info-LabVIEW - A LabVIEW electronic mailing list
- OpenG - Open-source LabVIEW utilities.
- The LabVIEW Wiki - A user editable LabVIEW knowledge base powered by MediaWiki.
- Free, online LabVIEW programming course - This course was authored by NI, and is hosted by Connexions.
- International multi-language (mostly Russian and German) forum and site dedicated to LabVIEW
- ITpointed LabVIEW Forum
- Dutch-language based user group dedicated to LabVIEW
- LabVIEW Turkey Project Community - Turkish
- Italian LabVIEW user Group - Italian
- LabVIEW link collection: tutorials, blogs, toolkits, hardwares
- [Labview source codes for labview programmers, Visit RFWireless World labview section