LabVIEW Tutorial

This article discusses LabVIEW (Laboratory Virtual Instrument Engineering Workbench), developed by National Instruments (NI). Engineers and scientists use LabVIEW for data acquisition, measurements, automation and many other applications.

LabVIEW is extensively used in many critical sectors worldwide, creating a huge demand for LabVIEW professionals. Learning LabVIEW not only equips you with a powerful tool but also opens the door to exciting career opportunities.

This LabVIEW tutorial will explore the basic concepts of LabVIEW, its components, and the essential tools available in the software in greater detail.

Table of Contents:

• What is LabVIEW?
• Features
• Components
• Data Types and Structures
• Tools Palette
• LabVIEW Menu
• Data Processing
• Error Handling Best Practices
• Advanced Capabilities
• Examples
• Advantages
• Frequently Asked Questions

What is LabVIEW?

LabVIEW is the software that helps develop programs using the Graphical (G) programming language. It supports data acquisition and control instruments through automation.

LabVIEW allows you to seamlessly design, monitor, and interact with test systems. Its many functions integrate with numerous protocols, formats, and buses, effectively controlling external instruments and hardware.

Let’s look at the terminologies used in traditional languages and LabVIEW. It helps to understand the difference between LabVIEW and other text-based programming languages.

Conventional languages	LabVIEW
C, C++, Java, etc.,	G language
Program	Virtual Instrument
Program Code	Block Diagram
Function/ Method	Function
Subroutine or subprogram	Sub-VI
User interface	Front panel

LabVIEW Features:

LabVIEW's features are exceptional. Let's break it down into the following sections.

• Ease of use — You can design VIs easily with LabVIEW. Also, you can view and modify control inputs.
• Cross-platform Support — The LabVIEW environment seamlessly supports platforms like Windows, MacOS, and Linux.
• Seamless integration — LabVIEW integrates with devices and instruments such as microprocessors, Digital Signal Processors (DSPs), and Field-programmable Gate Arrays (FPGAs).
• Real-time processing — LabVIEW supports real-time data acquisition, analysis, and reporting operations.
• Modular Programming — LabVIEW supports modular programming. That's because VIs are modular and have a hierarchy approach. They can be used within top-level programs or subprograms.

Next, We will dive into the LabVIEW components in the following section of this LabVIEW tutorial.

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LabVIEW Components:

The key components of LabVIEW are:

1. Virtual Instrument
2. Front Panel
3. Block Diagram
4. Icon And Connector Panes
5. Palette
6. Error Cluster

1.  Virtual Instrument (VI)

When you open a new or existing VI, the front panel appears. The front panel is the interactive user interface for the Virtual Instrument. It is named a front panel because it stimulates the front panel of a physical instrument.

LabVIEW uses subVIs in graphical programming, similar to subroutines in text-based programming languages. You can use a VI or subVI in another VI, but it requires an icon and a connector. 

LabVIEW uses subVIs in graphical programming, similar to subroutines in text-based programming languages. You can use a VI or subVI in another VI, but it requires an icon and a connector. 

You can also create custom virtual instruments to perform the tasks below.

• Operating the instrumentation program
• Analysing the acquired data
• Controlling hardware
• Displaying results

Further, SubVIs are custom-built LabVIEW functions that can be reused in multiple programs. They help accelerate program development and execution, improving productivity.

2.  Front Panel

A front panel in LabVIEW is an interface for users to interact with the controls and indicators. Using LabVIEW programs, users can enter input data, view the results, and control the front panel objects.

The elements of the front panel are:

• Controls – They include push buttons, dials knobs, sliders, and other input devices.
• Indicators – They contain graphs, LEDs, and Numerical displays.

Controls are input elements through which users can send input data into virtual instruments. On the other hand, indicators are output elements where users can view the output data generated by virtual instruments.

Moreover, LabVIEW allows you to customise the front panel. You can tailor the front panel for the reasons below.

• Simulating the control panels of conventional instruments
• Representing controls in visual form
• Creating custom test panels.

3.  Block Diagram

A block diagram in LabVIEW is constructed with graphical blocks to represent the logic of programs or VIs.

Block diagrams have a graphical source code composed of many elements. These elements help define the behaviour of LabVIEW programs.

Let's glance at the elements used in the LabVIEW block diagram.

• Functions – It includes operations such as mathematical calculations, data processing, and more.
• Terminals – They are entry and port ports used in LabVIEW. They help pass data between a block diagram and a front panel.
• Wires – They link functions to enable data flow between them
• Nodes -  Any programming element in a LabVIEW block diagram, excluding wires, terminals, bookmarks, or decorations.
• Structures – They are control flow elements such as for/while loops, etc.

In many ways, the block diagram resembles a flowchart. You will use wires to connect functional nodes. So you can easily understand the data flow in LabVIEW programs. 

4.  Icon and Connector Pane

An icon in LabVIEW is a graphical representation of a virtual instrument. It can include text and image information. A VI must have an icon and connector pane to be used as a subVI.

The connector pane determines the inputs and outputs you will wire in a Virtual Instrument. You can mainly use it as a subVI.  

5.  Palette

The palette in LabVIEW includes all the functions and tools you will use in block diagrams, virtual instruments, case structures and mathematical operations.

6.  Error Cluster

An error cluster has error handling tools, including the status message, error code, and Boolean indicator.

Well, you have gained some essential knowledge of LabVIEW components, which will help you learn more about LabVIEW.

LabVIEW Data Types and Structures:

LabVIEW supports different data types and structures. They are instrumental in developing LabVIEW programs.

 Let’s list the data types and structures below.

• Data types
  1. Boolean
  2. Numeric types
  3. Array
  4. String
  5. Cluster
  6. Variables
  7. Refnum
  8. waveform
• Structures
  1. For/while loops
  2. Conditional branching

Good! It’s time to jump into learning Labview tools in the following.

LabVIEW Tools Palette:

We will learn the LabVIEW tools palette in detail in this part of the LabVIEW tutorial.

The Tool palette shown in the Figure below is available on LabVIEW's front panel and block diagram. You can create, modify, and debug Virtual instruments using the tools in the tool palette. 

Let’s discuss the tools in the following.

• Common Tools
  1. Arrow tool – It helps to move objects in block diagrams. You can select functions, controls, and indicators using the tool.
  2. Connection tool – You can create wires to connect blocks in block diagrams
  3. Hand tool – You can navigate the block diagram or front panel without selecting objects
  4. Write text tool - It helps you write annotations for block diagrams.
• Advanced Tools
  1. Wire – It  includes tools to create different types of wires, such as simple wires, error wires and control wires
  2. Run/Stop  – It helps you to run and stop the execution of your VIs
  3. Edit  – It supports editing elements in block diagrams
  4. Debugging - This tool can identify and resolve program errors.

You can use the tools to operate and change the front panel and block diagram objects.

• Front Panel Controls Palette:

The control palette in the figure below is available only on the front panel. It contains the controls and indicators you need to create the front panel.

The control palette can be accessed from the front panel in the following ways.

1. 1. Selecting View → Controls Palette
   2. Right-clicking an open space on the front panel window to display the Controls palette.

Note that your chosen tool remains selected until you choose another tool from the Tools palette.

The Controls palettes contain sub-palettes of objects you can use to create a VI. When you click a subpalette icon, the entire palette changes to your selected subpalette. To use an object on the palettes, click the object and place it on the front panel.

The table below lists the tools in the toolbar of the Controls and Function palettes.

• Block Diagram Toolbar

Front panel objects appear as terminals on the block diagram. Terminals on the block diagram reflect the changes made to their corresponding front panel objects and vice versa.

The table below provides the details of the block diagram toolbar buttons. Click the following buttons on the block diagram toolbar to debug the VI.

Toolbar Buttons	Descriptions
Highlight execution button	When you click the run button, it displays the animation of the block diagram execution.
Retain wire values	It saves the wire values at every point in the execution flow.
Step into	It opens and pauses a node. When you click the ‘step into’ button, the first action is executed, and the following action is paused in a subVI.
Step Over	You can execute the current node and pause at the next node by clicking this button.
Step out	This button stops the execution in the current node and pauses.
Warning	If something goes wrong in a VI, this signal appears. It doesn’t stop VI execution.

I hope that you have understood LabVIEW’s tools palette well. In the next part of this tutorial, we will learn about LabVIEW menus.

LabVIEW Menus:

Every LabVIEW object and space on the front panel has a shortcut menu. This also applies to block diagrams. The object shortcut menu is one of LabVIEW's most commonly used shortcut menus.

The shortcut menu items allow you to change the appearance or behaviour of the front panel and block diagram objects.

To access the shortcut menu, follow the steps below.

1. Right-click the object, front panel, or block diagram.
2. Right-click the label in the figure below to access its shortcut menu for front panel objects.
   
3. Right-click the digital display to access its shortcut menu, as shown in the below Figure. 
   

The shortcut menu can create controls, constants, and indicators. The methods below will help you do this.

1. Right-click a functioning terminal.
2. Select Create → Constant, Create →Control, or Create → Indicator from the shortcut menu to create.
3. Right-click the node and select replace from the shortcut menu to replace nodes.

Data Processing in LabVIEW:

Let’s address the data processing in LabVIEW, such as file I/O and signal processing.

• File Input and Output Processing

LabVIEW provides many file-handling functions. The ‘write to file’ and ‘read from file’ functions allow you to read and write files, store data, and load configurations.

Let’s take a look at the functions.

1. 1. Read from file — You can use the 'read from text file' function to read data from a text file and load it on a VI for processing.
   2. Write to file—The 'write to spreadsheet file' function can load data into CSV files.
   3. File Path Control —  This special control is used in LabVIEW to select files or directories.

• Signal processing in LabVIEW.

LabVIEW offers many tools for signal processing and analysis. Users can process audio, control systems, data, and more.

1. 1. Signal Filtering  – LabVIEW offers various  built-in filters, including low-pass, high-pass and band-pass filters, for filtering signals
   2. Data analysis –  LabVIEW allows users to perform statistical analysis, Fourier transforms, and other crucial mathematical operations.
   3. Displaying data –  LabVIEW offers visualisation tools like graphs and charts to display signals over time.

Related Article : Customizing Graphs And Charts In Labview 

LabVIEW Error Handling Best Practices:

LabVIEW provides robust debugging and error-handling techniques for users.

• LabVIEW highlights program execution flow step-by-step for users
• It provides probes to examine data flow status at any point in a wire.
• If an error is identified in one of the SubVI, the following SubVIs needn’t be executed.
• All the error handling conditions are added within error clusters, which will be automatically handled based on conditions.
• You can identify error inputs and error outputs within a SubVI Using the error cluster controls and indicators.
• You have many options to determine how a subVI must be executed when encountering an error.

Implementing these best practices will help manage LabVIEW errors effectively and boost performance.

Advanced capabilities of LabVIEW:

Some of LabVIEW's advanced capabilities are state machine architecture and the LabVIEW FPGA module. Let’s examine these concepts closely.

• Application Design Patterns - State Machines

State machine architecture is a design pattern developers use to build complex, state-driven applications. State machines can also be used to implement complex decision-making algorithms. 

You can use LabVIEW’s innate functions to implement state machines. Fortunately, you don't need any additional kit to implement it in LabVIEW.

When you translate the state diagram into a LabVIEW program architecture, you need the following elements.

1. 1. While loop
   2. Shift register
   3. Case structure
   4. Transition code

• LabVIEW FPGA Module

The LabVIEW Field Programmable Gate Arrays (FPGA) module is an advanced integrated development environment for efficiently designing complex systems. 

This module also includes a high-fidelity simulator, IP libraries, and troubleshooting features. It allows developers to design digital circuits graphically on NI FPGA hardware.

Above all, the LabVIEW FPGA module helps perform parallel processing tasks at a high pace.

LabVIEW Example:

In this section of the LabVIEW tutorial, we will go through a LabVIEW example.  

Let’s dive in.

• Step-by-step procedure to create a VI:

Next, we will learn how to create a VI in Labview to find the area of a triangle. Here we go:

• • Installation: Download and install the LabVIEW software using the link.https://www.ni.com/en/support/downloads/software-products/download.labview.html#544096 
  • Initialising the VI:
    1. Open a blank VI from the toolbar in the following way
    2. Select  File → New VI.
    3. Navigate to Programming → Numeric subpalette.
    4. Select two multiply functions and drag them onto the block diagram
  • Creating Controls 
    1. When you move your mouse over one of the terminals of the multiply function, the wire appears.
    2. Right-click on the two inputs of the function to create controls for it.
       
    3. Next, wire the output terminal of the multiply function as the input of another multiply function.
       
    4. Right-clicking on the ‘y’ input terminal of the second multiply function to create the Triangular Multiplier constant 0.5
    5. Select Create → Constant.
       
  • Creating indicator: 
    1. Right-click the output of the right multiply function
    2. Select Create → Indicator to create an indicator
       
    3. You will get the front panel as shown in the below figure.
       
  • Adding functions:
    1. Select a While Loop from the Programming → Structures subpalette.
    2. left-click the while loop and drag it to the block diagram
    3. Add a Stop button by right-clicking the terminal and selecting Create Control
    4. navigate to Programming → Timing subpalette  to add a Wait function  Inside the While Loop,
    5. Right-click on the milliseconds on the wait function if you want to change the time.
       
  • Running and saving the VI:
    1. Click the Run button on the VI and change the values on the front panel.
    2. Click the Stop button to stop the VI.
    3. Save and close the VI.

Congrats! You have created a VI in LabVIEW to calculate the area of a triangle.

Advantages of LabVIEW:

Let's look at the advantages of LabVIEW. 

• Developers take less time to build applications using LabVIEW than traditional programming languages.
• LabVIEW’s graphical user interface (GUI) makes LabVIEW easy for programming.
• It offers extensive libraries of functions and subroutines, simplifying programming tasks.
• It provides high flexibility in creating and modifying virtual instruments
• It contains special libraries related to data management, which are helpful for data analysis, storage, presentation, etc.
• You can visualise output data in any graphical format, i.e. charts, graphs, etc.
• LabVIEW programs are portable. You can write one on one platform and run it on another seamlessly.

Great! We hope this LabVIEW tutorial has given you a comprehensive knowledge of the concepts and features of LabVIEW.

Summary:

• LabVIEW stands for Laboratory Virtual Instrument Engineering Workbench.
• It is a graphical programming development platform
• Front panel and block diagram are the key components of LabVIEW
• LabVIEW’s programs are known as virtual instruments
• Nodes are the building blocks of a LabVIEW program, which includes subroutines, functions, and operations
• LabVIEW supports prototypes such as numeric, string, Boolean, array and cluster
• It supports different data structures, including for and while loops
• LabVIEW plays a key role in data acquisition, instrument control, data analysis and processing, and more.

For those preparing for a career in LabVIEW, it's essential to review common LabVIEW Interview Questions that can help you succeed in your job search.

Frequently Asked Questions

1. What is the latest version of LabVIEW software?

Ams: LabVIEW 2024 Q3 is the latest version, released in July 2024.

2. What is the future scope for LabVIEW professionals?

Ans: Here are the reasons why LabVIEW professionals have a bright future.

• Many companies leverage LabVIEW to increase their organisations' productivity.
• Many job opportunities exist in the current job market, where organisations pay heavy salaries.
• Companies use this software to build prototypes and Proof of Concepts (PoC)
• According to AmbitionBox, LabVIEW developers can earn a salary ranging from 3 LPA to 8 LPA at the entry level in India. According to Talent.com, they can earn a salary ranging from 96k USD to 156k USD in the USA. So, the future of LabVIEW professionals is promising.

3. Is LabVIEW an easy programming language?

Ans: Yes, LabVIEW is an easy programming language. Instead of text-based programming, you will use a graphical programming approach. MindMajix offers 30-hour LabVIEW training with a strong focus on practical learning.

4. How to become a LabVIEW developer?

Ans:

• Join MindMajix for industry-focused LabVIEW training.
• Go through online classroom and lab sessions
• Work on real-time projects and industry samples
• Attend the career guidance and job assistance programs
• Become a competent LabVIEW developer

5. What are the available LabVIEW certifications?

Ans: The following are the various LabVIEW certifications.

• Certified LabVIEW Associate Developer – CLAD
• Certified LabVIEW Architect – CLA
• Certified LabVIEW Developer – CLD
• Certified LabVIEW Embedded Systems Developer – CLED
• Certified Teststand Developer – CTD
• Certified Teststand Architect – CTA

6. What are the job roles that you can apply for after learning LabVIEW?

Ans: 

• LabVIEW Developer
• LabVIEW Engineer
• LabVIEW Architect

Conclusion:

LabVIEW's user interface and graphical programming language help to build graphical programs. In this LabVIEW tutorial, we covered the basics of the LabVIEW interface, including the Front Panel, Block Diagram, Tools Palette, and many more.

If you want to explore the tools available in the Tools Palette and understand the basic LabVIEW programming concepts, you can sign up for MindMajix’s LabVIEW training. Once you complete the training, you will become proficient in creating VIs on your own for different applications.

Explore - LabVIEW Sample Resumes! Download & Edit, Get Noticed by Top Employers!.