LabVIEW
Laboratory Virtual Instrument Engineering Workbench is a system-design platform and development environment for a visual programming language from National Instruments.
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 operating systems, including Microsoft Windows, various versions of Unix, Linux, and macOS.
The latest versions of LabVIEW are LabVIEW 2019 SP1 and LabVIEW NXG 4.0, released in November 2019. NI released the free for non-commercial use LabVIEW and LabVIEW NXG Community editions on April 28th, 2020.
Dataflow programming
The programming paradigm used in LabVIEW, sometimes called G, is based on data availability. If there is enough data available to a subVI or function, that subVI or function will execute. Execution flow is determined by the structure of a graphical block diagram 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, LabVIEW can execute inherently in parallel. Multi-processing and multi-threading hardware is exploited automatically by the built-in scheduler, which multiplexes multiple OS threads over the nodes ready for execution.Graphical programming
LabVIEW integrates the creation of user interfaces into the development cycle. LabVIEW programs-subroutines are termed virtual instruments. Each VI has three components: a block diagram, a front panel, and a connector pane. 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 are 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 be run as either 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 nonprogrammers 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 a 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 ability to build stand-alone applications. Furthermore, it is possible to create distributed applications, which communicate by a client–server model, and are thus easier to implement due to the inherently parallel nature of G.
Widely-accepted design patterns
Applications in LabVIEW are usually designed using well-known architectures, known as design patterns. The most common design patterns for graphical LabVIEW applications are listed in the table below.| Design pattern | Purpose | Implementation details | Use cases | Limitations |
| Functional Global Variable | Exchange information without using global variables | A shift register of a while loop is used to store the data and the while loop runs only one iteration in a "non-reentrant" VI |
| |
| State machine | Controlled execution that depends on past events | Case structure inside a while loop pass an enumerated variable to a shift register, representing the next state; complex state machines can be designed using the Statechart module | ||
| Event-driven user interface | Lossless processing of user actions | GUI events are captured by an event structure queue, inside a while loop; the while loop is suspended by the event structure and resumes only when the desired events are captured | ||
| Master-slave | Run independent processes simultaneously | Several parallel while loops, one of which functions as the "master", controlling the "slave" loops | ||
| Producer-consumer | Asynchronous of multithreaded execution of loops | A master loop controls the execution of two slave loops, that communicate using notifiers, queues and semaphores; data-independent loops are automatically executed in separate threads | ||
| Queued state machine with event-driven producer-consumer | Highly responsive user-interface for multithreaded applications | An event-driven user interface is placed inside the producer loop and a state machine is placed inside the consumer loop, communicating using queues between themselves and other parallel VIs |
Benefits
Interfacing to devices
LabVIEW includes extensive support for interfacing to devices such as instruments, cameras, and other devices. Users interface to hardware by either writing direct bus commands 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 and Virtual Instrument Software Architecture toolsets.
National Instruments makes thousands of device drivers available for download on the NI Instrument Driver Network.
Code compiling
LabVIEW includes a compiler that produces native code for the CPU platform. The graphical code is converted into Dataflow Intermediate Representation, and then translated into chunks of executable machine code by a compiler based on LLVM. Run-time engine calls these chunks, allowing better performance. 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 binary file. The execution is controlled by LabVIEW run-time engine, which contains some pre-compiled code to perform common tasks that are defined by the G language. The run-time engine governs execution flow, and provides a consistent interface to various operating systems, graphic systems and hardware components. The use of run-time environment makes the source code files portable across supported platforms. LabVIEW programs are slower than equivalent compiled C code, though like in other languages, program optimization often allows to mitigate issues with execution speed.Large libraries
Many libraries with a large number of functions for data acquisition, signal generation, mathematics, statistics, signal conditioning, analysis, etc., along with numerous for functions such as integration, filters, and other specialized abilities usually associated with data capture from hardware sensors is enormous. In addition, LabVIEW includes a text-based programming component named MathScript with added functions for signal processing, analysis, and mathematics. MathScript can be integrated with graphical programming using script nodes and uses a syntax that is compatible generally with MATLAB.Parallel programming
LabVIEW is an inherently concurrent language, so it is very easy to program multiple tasks that are performed in parallel via multithreading. For example, this is done easily by drawing two or more parallel while loops and connecting them to two separate nodes. 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.Ecosystem
Due to the longevity and popularity of the LabVIEW language, and the ability for users to extend its functions, a large ecosystem of third party add-ons has developed via 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.User community
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 electronic mailing lists and Internet forums.Home Bundle Edition
provides a low cost LabVIEW Home Bundle Edition.Free for Non-Commercial use, Edition
National Instruments provides a free for non-commercial use version called LabVIEW Community Edition. This version includes everything in the Professional Editions of LabVIEW, has no watermarks, and includes the LabVIEW NXG Web Module for non-commercial use. These editions may also be used by K-12 schools.Criticism
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 American National Standards Institute, Institute of Electrical and Electronics Engineers, International Organization for Standardization, etc. Some users have criticised it for its tendency to freeze or crash during simple tasks, requiring the software to be shut down and restarted.Slow
Very small applications still have to start the run-time environment which is a large and slow task. This tends to restrict LabVIEW to larger applications. Examples of this might be tiny programsto grab a single value from some hardware that can be used in a scripting language - the overhead of
the run-time environment render this approach impractical with LabVIEW.
Non-textual
Since G language is non-textual, software tools such as versioning, side-by-side comparison, and version code change tracking cannot be applied in the same manner as for textual programming languages. There are some additional tools to make comparison and merging of code with source code control tools such as subversion, CVS and Perforce.No zoom function
There was no ability to zoom in to a VI which will be hard to see on a large, high-resolution monitor. However, the ability to zoom has been added into LabVIEW NXG.Release history
In 2005, starting with LabVIEW 8.0, major versions are released around the first week of August, to coincide with the annual National Instruments conference NI Week, and followed by a bug-fix release the following February.In 2009, National Instruments began naming releases after the year in which they are released. A bug-fix is termed a Service Pack, for example, the 2009 service pack 1 was released in February 2010.
In 2017, National Instruments moved the annual conference to May and released LabVIEW 2017 alongside a completely redesigned LabVIEW NXG 1.0 built on Windows Presentation Foundation.
| Name-version | Build number | Date |
| LabVIEW project begins | April 1983 | |
| LabVIEW 1.0 | ?? | October 1986 |
| LabVIEW 2.0 | ?? | January 1990 |
| LabVIEW 2.5 | ?? | August 1992 |
| LabVIEW 3.0 | ?? | July 1993 |
| LabVIEW 3.0.1 | ?? | 1994 |
| LabVIEW 3.1 | ?? | 1994 |
| LabVIEW 3.1.1 | ?? | 1995 |
| LabVIEW 4.0 | ?? | April 1996 |
| LabVIEW 4.1 | ?? | 1997 |
| LabVIEW 5.0 | ?? | February 1998 |
| LabVIEW RT | ?? | May 1999 |
| LabVIEW 6.0 | 6.0.0.4005 | 26 July 2000 |
| LabVIEW 6.1 | 6.1.0.4004 | 12 April 2001 |
| LabVIEW 7.0 | 7.0.0.4000 | April 2003 |
| LabVIEW PDA module first released | ?? | May 2003 |
| LabVIEW FPGA module first released | ?? | June 2003 |
| LabVIEW 7.1 | 7.1.0.4000 | 2004 |
| LabVIEW Embedded module first released | ?? | May 2005 |
| LabVIEW 8.0 | 8.0.0.4005 | September 2005 |
| LabVIEW 8.20 | ?? | August 2006 |
| LabVIEW 8.2.1 | 8.2.1.4002 | 21 February 2007 |
| LabVIEW 8.5 | 8.5.0.4002 | 2007 |
| LabVIEW 8.6 | 8.6.0.4001 | 24 July 2008 |
| LabVIEW 8.6.1 | 8.6.0.4001 | 10 December 2008 |
| LabVIEW 2009 | 9.0.0.4022 | 4 August 2009 |
| LabVIEW 2009 SP1 | 9.0.1.4011 | 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 | August 2011 | |
| LabVIEW 2011 | 11.0.0.4029 | 22 June 2011 |
| LabVIEW 2011 SP1 | 11.0.1.4015 | 1 March 2012 |
| LabVIEW 2012 | 12.0.0.4029 | August 2012 |
| LabVIEW 2012 SP1 | 12.0.1.4013 | December 2012 |
| LabVIEW 2013 | 13.0.0.4047 | August 2013 |
| LabVIEW 2013 SP1 | 13.0.1.4017 | March 2014 |
| LabVIEW 2014 | 14.0 | August 2014 |
| LabVIEW 2014 SP1 | 14.0.1.4008 | March 2015 |
| LabVIEW 2015 | 15.0f2 | August 2015 |
| LabVIEW 2015 SP1 | 15.0.1f1 | March 2016 |
| LabVIEW 2016 | 16.0.0 | August 2016 |
| LabVIEW 2017 | 17.0f1 | May 2017 |
| LabVIEW NXG 1.0 | 1.0.0 | May 2017 |
| LabVIEW 2017 SP1 | 17.0.1f1 | Jan 2018 |
| LabVIEW NXG 2.0 | 2.0.0 | Jan 2018 |
| LabVIEW 2018 | 18.0 | May 2018 |
| LabVIEW NXG 2.1 | 2.1.0 | May 2018 |
| LabVIEW 2018 SP1 | 18.0.1 | Sep 2018 |
| LabVIEW NXG 3.0 | 3.0.0 | Nov 2018 |
| LabVIEW 2019 | 19.0 | May 2019 |
| LabVIEW NXG 3.1 | 3.1.0 | May 2019 |
| LabVIEW 2019 SP1 | 19.0.1 | Nov 2019 |
| LabVIEW NXG 4.0 | 4.0.0 | Nov 2019 |
| LabVIEW 2020 and LabVIEW NXG 5.0 Community Editions first released | April 2020 |
Repositories and libraries
, as well as LAVA Code Repository, 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 libraries for LabVIEW.
Tools exist to convert MathML into G code.
Related software
National Instruments also offers a product named Measurement Studio, which offers many of the test, measurement, and control abilities 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 need sequencing, users often use LabVIEW with TestStand test management software, also from National Instruments.
The Ch interpreter is a C/C++ interpreter that can be embedded in LabVIEW for scripting.
DSP Robotics' FlowStone DSP also uses a form of graphical programming similar to LabVIEW, but is limited to the robotics industry 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.