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Learn about the LabVIEW programming environment, create your first virtual instrument (VI), learn about LabVIEW's dataflow programming paradigm,become acquainted with some of LabVIEW's data types, and review some useful debugging techniques.

Overview

Welcome to the exciting world of LabVIEW for audio and signal processing applications! This module contains five screencast videos, meaning that the videos were captured directly from my computer screen. As I operate the LabVIEW software, I explain each step and discuss what is going on. After you watch each of the videos, you will possess a good idea of some fundamental LabVIEW concepts, including:

  • Front panel and block diagram programming paradigm
  • Dataflow paradigm
  • Data types
  • Broken wires
  • Debugging techniques

A bit of history

In 1986 National Instruments Corporation released the first version of LabVIEW ( Lab oratory V irtual I nstrument E ngineering W orkbench), which was designed to help engineers use a computer (the Apple Macintosh) to control and gather data from electronic instrumentation (voltmeters, oscilloscopes, and the like) all interconnected by the standard General Purpose Instrumentation Bus, or GP-IB. From its inception, LabVIEW programming was graphical in nature. Instead of writing a text file and compiling it to an executable, you connect various elements such as controls , indicators , nodes and subVIs together with wires , and in this way create a block diagram . The controls and indicators reside on the front panel , which looks just a traditional electronic instrument, i.e., it can have knobs, sliders, buttons, and display panels. The complete application is called a virtual instrument , or VI for short.

LabVIEW has since evolved into a complete programming environment; anything that you can imagine can probably be implemented in LabVIEW. Recent versions of LabVIEW have added a full suite of tools for doing signal processing, and since soundcard operations are provided, it becomes natural to develop audio signal processing applications in LabVIEW.

LabVIEW’s interactive front panel offers a unique opportunity to explore signal processing concepts in real time. As you work your way through other modules in this series, you will learn how to implement your own applications whose user interface consists of knobs, sliders and switches that can adjust processing parameters while you listen to the results.

Your first virtual instrument (vi)

Watch the following screencast video to learn how to connect front panel controls and indicators together. You will also learn how to use the While Loop structure to make your VI operate continuously until you press a “STOP” button on the front panel.

[video] Creating your first "VI" (Virtual Instrument)

The dataflow concept

The notion of LabVIEW’s dataflow programming paradigm must be grasped immediately in order for you to make forward progress learning about LabVIEW to create your own applications. Dataflow programming means that valid data must be present at all of the input terminals on a node (or subVI) before that node (or subVI) will produce valid data on its output terminals. Moreover, the node (or subVI) does not continually process its inputs data unless it is embedded in some sort of looping structure.

Click on the following animation of the dataflow concept to watch a screencast video that explains and further explores the dataflow programming concept.

[video] Understanding the LabVIEW "dataflow" paradigm

Data types

LabVIEW supports a broad range of data types , including numeric , Boolean , and string . The following screencast video will acquaint you with the floating point and integer styles of numeric data type, as well as the Boolean data type. The screencast explains the significance of the coercion indicator -- the red dot that flags a mismatch on data types applied to the input of a node or subVI -- as well as data type conversion nodes that you can use to intentionally convert a value from one data type to another.

[video] Datatypes: Numeric and Boolean

Broken wires

Broken wires indicate an error that must be corrected before your VI will run. Broken wires result from a number of causes, and it is important to understand why the wire is broken and how to correct the situation. The following screencast describes broken wires in detail.

[video] Understanding and correcting broken wires

Debugging techniques

As you begin learning LabVIEW so that you can develop your own VIs, you will find the debugging techniques described by the next screencast video helpful. Topics include adding additional indicators, using the Highlight Execution feature, using the Retain Wire Values feature, single-stepping , viewing wire values using probes , and creating breakpoints to pause execution when new data is available on a wire.

[video] Basic debugging techniques

For further study

If you are new to LabVIEW, I recommend the excellent text by Robert H. Bishop, Learning with LabVIEW 8 (Pearson Prentice Hall, 2007, ISBN 0-13-239025-6) . With this text you can learn basic LabVIEW programming techniques and get a better idea of everything that LabVIEW has to offer.

Once you have developed some skill with LabVIEW, consider Peter A. Blume’s text, The LabVIEW Style Book (Prentice Hall 2007, ISBN 0-13-145835-3) . This text covers a wide variety of techniques that will help you to develop robust and well-designed LabVIEW applications.

Don’t forget to check out the on-line documentation that is part of your LabVIEW product installation.

Visit the National Instruments website, including their Academic page and the NI Developer Zone .

Questions & Answers

find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
Abhi
how do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
hmm
Abhi
is it a question of log
Abhi
🤔.
Abhi
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
hii
Uday
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Musical signal processing with labview -- programming techniques for audio signal processing. OpenStax CNX. Jul 18, 2007 Download for free at http://cnx.org/content/col10440/1.1
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