Introduction to LabVIEW Short

8/10/2019 Introduction to LabVIEW Short

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Introduction to LabVIEW

[email protected]
mailto:[email protected]:[email protected]:[email protected]://www.ni.com/


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LabVIEW Graphical Development System

Useful in a broad range of applicationsCan compile code for multiple OS and devices
http://www.ni.com/http://c/eluther/www.ni.com/http://c/eluther/ni.com/


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Virtual Instrumentation Applications Measurements

Circuits and Electronics Measurements and Instrumentation

Control

Plant modeling forControl

Automatic Controls and Dynamic Systems Mechatronics and Robotics

Design

Signal and Image Processing

Embedded System Programming

(PC, DSP, FPGA, Microcontroller)

Simulation and Prototyping

Design Prototype Deploy

A single graphical development platform


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The NI Approach Integrated Hardware Platforms

High-SpeedDigitizers

High-ResolutionDigitizers and DMMs

MultifunctionData Acquisition

DynamicSignal Acquisition

Digital I/OInstrumentControl

Counter/Timers

MachineVision

MotionControl

Distributed I/O andEmbedded Control

Laptop PC PDADesktop PCPXI Modular Instrumentation

Signal Conditioning

and Switching

Unit Under Test


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Section I LabVIEW EnvironmentLabVIEW Environment

Front Panel / Block Diagram Toolbar /Tools Palette

Data Flow Execution

Debugging Techniques

Components of a LabVIEW Application Creating a VI

C. Additional Help

Context Help Data Flow Execution

Debugging


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Start>All Programs>National Instruments LabVIEW 8.6

On Getting Started Screen

open one of the following:

1. Blank VI: New>Blank VI

2. Empty Project: New>Empty Projects

3. Example: Examples>Find Examples

Open and Run LabVIEW


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Each VI has2 Windows:

1. Front Panel

2. Block Diagram

LabVIEW Programs Are Called Virtual Instruments (VIs)


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User Interface (UI)

Controls = Inputs Indicators = Outputs

VI Front Panel


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Graphical Code

Data travels on wires fromcontrols through functions to

indicators

Blocks execute by Dataflow

VI Block Diagram


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Controls Palette (Controls & Indicators)

Customize

Palette

View

(Places items on the Front Panel Window)


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Indicator:Numeric Slide


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Control:Numeric


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Functions (and Structures) Palette(Places items on the Block Diagram Window)

Structure:While Loop


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Run Button

Continuous Run Button

Abort Execution

Status Toolbar


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Context Help Window

Help>Show Context Help or keys

Hover cursor over object to update window

Additional Help

Right-Click on the VI icon and

chooseHelp, or

Choose Detailed Help. on

the context help window


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Block diagram execution

Dependent on the flow of data

Block diagram does NOT execute

left to right

Node executes when data is

available to ALL input terminals

Nodes supply data to all outputterminals when done

Dataflow Programming


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Debugging Techniques

Finding Errors

Execution Highlighting

Probes

Click on broken Run button.

Window showing error appears.

Click on Execution Highlighting button; dataflow is animated using bubbles. Values aredisplayed on wires.

Right-click on wire to display probe and it showsdata as it flows through wire segment.

You can also select Probe tool from Tools paletteand click on wire.


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Additional Buttons on

the Diagram Toolbar

Status Toolbar

Execution Highlighting Button

Retain Wire Values Button

Step Function Buttons


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Section II Elements of Typical ProgramsFunctions

Types of Functions Functions Palette & Searching

Loops

While Loop For Loop

Decision Making and File IO Case Structure

Select (simple If statement)

File I/O


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Types of Controls and Indicators Available

Numeric Data Number input and display

Analog Sliders, Dials, and Gauges

Boolean Data Buttons and LEDs

Ar ray & Matrix Data Numeric Display

Chart

Graph

XY Graph

Intensity Graph

3D graph: point, surface, and

model

Express Controls Palette

Decorations-Tab Control-Arrows

Other- Strings and text boxes- Picture/Image Display-ActiveX Controls


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Types of Functions Available

Input and Output

Signal and Data Simulation Acquire and Generate Real Signals with DAQ

Instrument I/O Assistant (Serial & GPIB)

ActiveX for communication with other programs

Analysis Signal Processing

Statistics

Advanced Math and Formulas

Continuous Time Solver

Storage

File I/O

Express Functions Palette


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Types of Functions (from the Functions Palette)

Functionsfundamental operating elements of LabVIEW;

no front panel or block diagram (yellow)

Express VIinteractive VIs with configurable dialog page (blue border)

Standard VI

modular VIs customized by wiring


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Searching for Controls, VIs, and Functions

Palettes are filled with hundreds

of VIs

Press the search button to index the

all VIs for text searching

Click and drag an item from the

search window to the block diagram

Double-click an item to open the

owning palette


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Loops

While Loopsi terminal counts iteration

Always runs at least once

Runs until stop condition is

met

For Loopsi terminal counts iterations

Run according to input N of

count terminal

While Loop

For Loop


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Drawing a Loop

1. Select the structure

2. Enclose code to be repeated

3. Drop or drag additional nodes and then wire


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Timing a Loop

1. Loop Time Delay

Configure the Time Delay Express VI for seconds to waiteach iteration of the loop (works on For and While loops).

2. Timed Loops Configure special timed While loop for desired dt.

Timed LoopTime Delay


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Shift Register Access Previous Loop Data

Available at left or right border of loop structures

Right-click the border and selectAdd Shift Register Right terminal stores data on completion of iteration

Left terminal provides stored data at beginning of next iteration

BeforeLoop

BeginsFirst

IterationSecondIteration

LastIteration

Value 3InitialValue


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Making Decisions

1. Case Structures

2. Select(a) (b)

(c)


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Create SubVI

Enclose area to be converted into a subVI.

Select EditCreate SubVI from the Edit Menu.


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LabVIEW Functions and SubVIs operate like subroutinesin other languages

Function Pseudo Codefunction average (in1, in2, out)

{

out = (in1 + in2)/2.0;

}

SubVI Block Diagram

Calling Program Pseudo Codemain

{

average (in1, in2, pointavg)

}

Call ing VI Block Diagram


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Textual Math in LabVIEW

Integrate existing scripts with LabVIEW for faster development

Interactive, easy-to-use, hands-on learning environment

Develop algorithms, explore mathematical concepts, and

analyze results using a single environment

Freedom to choose the most effective syntax, whethergraphical or textual within one VI

Supported Math Tools:

MathScript script node MathSoft software

Mathematica software MATLAB softwareMaplesoftware Xmathsoftware

MATLAB is a registered trademark of The MathWorks, Inc.


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Math with the MathScript Node

Implement equations and algorithms textually

Input and Output variables created at the border Generally compatible with popular m-file script language

Terminate statements with a semicolon to disable immediate

output

Prototype your equations in the interactive MathScript Window.

(FunctionsProgrammingStructuresMathScript)


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The Interactive MathScript Window

Rapidly develop and test algorithms

(LabVIEWToolsMathScript Window)

OutputWindow

Variable

Workspace

View/Modify

Variable Contents

User Commands

m-file Script

Share Scripts andVariables with the Node

View /Modify Variable

content in 1D, 2D, and 3D


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File I/O

File I/O passing data to and from files

Files can be binary, text, or spreadsheet

Write/Read LabVIEW Measurements file (*.lvm)

Writing to LVMfile Reading from LVMfile


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File I/O Programming Model Under the hood

Open/Create/

Replace File

Readand/or

Write to File

Close

File

Check for

Errors


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Section III Presenting your Results

Displaying Data on the Front Panel Controls and Indicators

Graphs and Charts

Signal Processing - advanced

Arrays and clusters

Waveforms Projects


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Control & Indicator Properties

Properties are characteristics or qualities about an object

Properties can be found by right clicking on a Control or Indicator Properties Include:

Size

Color

Plot Style

Plot color

Features include:

CursorsScaling


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Graphs Display many data points at once

Waveform graph

special numeric indicator that displays an array ofdata

Graph updates after all points have been collected

May be used in a loop if VI collects buffers of dataFunctionsExpressGraph IndicatorsGraph


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Charts Add 1 data point at a time with historyWaveform chart special numeric indicator that can display a historyof valuesChart updates with each individual point it receives

FunctionsExpressGraph IndicatorsChart


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Advanced topics


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Introduction to Clusters

Data structure that groups data together Data may be of different types

Analogous to struct in C

Elements must be either all controls or all indicators Thought of as wires bundled into a cable

Order is important


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Arrays and Clusters into Graphs

The Waveform Datatype contains 3 pieces of data: t0 = Start Time

dt = Time between Samples

Y = Array of Y magnitudes

Two ways to create a Waveform Cluster:

Build Waveform (absolute time) Cluster (relative time)


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LabVIEW Project

Group and organize VIsHardware and I/O management

Manage VIs for multiple targets

Build libraries and executables

Manage large LabVIEW applications

Enable version tracking and management

(LabVIEW>Project>New)


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Additional Resources NI Academic Web & Student Corner

http://www.ni.com/academic

Connexions: Full LabVIEW Training Course

www.cnx.rice.edu

Or search for LabVIEW basics

LabVIEW Certification

LabVIEW Fundamentals Exam (free on www.ni.com/academic)

Certified LabVIEW Associate Developer Exam (industry recognized certification )

Get your own copy of LabVIEW Student Editionwww.ni.com/academic

ByRobert H Bishop.

Published byPrentice Hall.
http://www.ni.com/academichttp://www.cnx.rice.edu/http://cnx.rice.edu/content/col10241/latest/http://www.ni.com/academichttp://www.ni.com/academichttp://www.phptr.com/authors/bio.asp?a=680855aa-0b6f-441f-8280-53f8f7b5f51bhttp://vig.prenhall.com/http://vig.prenhall.com/http://www.phptr.com/authors/bio.asp?a=680855aa-0b6f-441f-8280-53f8f7b5f51bhttp://www.ni.com/academichttp://www.ni.com/academichttp://cnx.rice.edu/content/col10241/latest/http://www.cnx.rice.edu/http://www.ni.com/academichttp://www.ni.com/http://c/eluther/www.ni.com/http://c/eluther/ni.com/


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The LabVIEW Certification Program

Certified LabVIEW

Developer

Certif ied LabVIEW Associate

Developer

CertifiedLabVIEW

Arch itect

Architect

Mastery of LabVIEW Expert in large application development

Skilled in leading project teams

Developer Advanced LabVIEW knowledge

and application development

experience Project management skills

Associate Developer Proficiency in navigating

LabVIEW environment

Some applicationdevelopment experience

Fundamentals ExamPre-Certification Skills Test Free On-Line Fundamentals Exam


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Introduction to LabVIEW Short