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Co ur se Goals
• Become comfortable with the LabVIEW environment and data flow execution
• Ability to use LabVIEW to solve problems• LabVIEW Concepts
– Acquiring, saving and loading data– Find and use math and complex analysis functions– Work with data types, such as arrays and clusters– Displaying and printing results
La bVI EW Grap hical De velop ment S yst em
• Graphical Programming Environment• Compile code for multiple OS and devices• Useful in a broad range of applications
Virtua l Inst rumen tat ion App li ca t io ns• Des ign
– Signal and Image Processing– Embedded System Programming
• (PC, DSP, FPGA, Microcontroller)– Simulation and Prototyping– And more…
• Control– Automatic Controls and Dynamic Systems– Mechatronics and Robotics– And more…
• Meas urem ents– Circuits and Electronics– Measurements and Instrumentation– And more…
Design Prototype Deploy
A single graphical development platf orm
The NI Approach – Integrated Hardware Platforms
Hig h-S peedDig itiz ers
Hig h -Reso lu tio nDig itiz e rs a nd DMM s
Mu lti functio n Da ta Acq u isi t ion
Dyn amicS igna l A cqu is itio n
Dig ita l I/ OIn stru me n tContro l
Counter/T ime rs
Mach ineV isio n
Mo tio n Con tro l
D istr ib u te d I/O a ndEmb edded Con tro l
Lapto p P C PDADeskto p P CPXI Mo dula r In stru me n ta ti on
S igna l C ond itio n in gand Sw itch in g
Un it Under T est
Sect io n I – La bVI EW En vir onme ntA. Getting Data into your Computer
• Data Acquisition Devices– NI-DAQ– Simulated Data Acquisition– Sound Card
B. LabVIEW Environment• Front Panel / Block Diagram• Toolbar /Tools Palette
C. Components of a LabVIEW Application• Creating a VI• Data Flow Execution
D. Additional Help• Finding Functions• Tips for Working in LabVIEW
A. Sett in g Up Yo ur Ha rd wa re
• Data Acquisition Device (DAQ)– Actual USB, PCI, or PXI Device– Configured in MAX
• Simulated Data Acquisition Device (DAQ)– Software simulated at the driver level– Configured in MAX
• Sound Card– Built into most computers
Track ATrack A
Track BTrack B
Track CTrack C
What type of device s hould I us e?
xxx—Trigg er ing
x
AC/DC
2–4
16–80
—
14–18 bit
250 K–1. 2 Ms/ s
NI PC I DAQ
somexxPor ta ble
20kS/s–2 GS/ s10–200 KS/s
8–44 KS/sAI Band widt h
x
AC/DC
0
2
12–24 bi t
Instruments*
x
AC/DC
1–2
8–16
12–16 bit
NI USB DAQ
—Ca li brated
ACAC or D C
2AO Ch annels
2AI Ch annels
12–16 bi tAccur ac y
Sound Card*
* T he abo ve tab le may no t be rep resen tative of al l de v ice varia t ions that exist i n ea ch c ategory
What is MA X?• MAX stands for Measurement & Automation Explorer.
• MAX configures and organizes all your National Instruments DAQ, PCI/PXI instruments, GPIB, IMAQ, IVI, Motion, VISA, and VXI devices.
• Used for configuring and testing devices.
Icon Found onIcon Found on
Windows DesktopWindows Desktop
Ex ercis e 1 – Se tting Up Your Device• Use Measurement and Automation Explorer (MAX) to:
– Configure and test your Data Acquisition (DAQ) device
Track ATrack A
Ex ercis e 1 – Se tting Up Your Device• Use Measurement and Automation Explorer (MAX) to:
– Configure and test your Simulated Data Acquisition (DAQ) device
Track BTrack B
Ex ercis e 1 – Se tting Up Your Device•Use Windows to:
–Verify your Sound Card
Track CTrack C
Un-Mute Microphone
Sta rt »Al l P ro grams »N ation al In st ruments LabVIE W
Sta rtu p Scr een:
Start from a Blank VI :
New»Blan k VI
Start from an Example:
Ex am ples»F ind Ex amples …
»
or
Open and Run LabVIEW
Each VI has 2 Windows
Fr ont P anel• User Interface (UI)
– Controls = Inputs– Indicators = Outputs
Block D iagram• Graphical Code
– Data travels on wires from controls through functions to indicators
– Blocks execute by Dataflow
LabVIEW Programs Are Called Virtual Instruments (VIs)
Con trols Pale t te(Con trols & Indicator s)
(Place items on the Front Panel Window)
Indicator:Numeric Slide
Control:Numeric
Cu sto mize Pa lett e
Vi ew
Fun ction s (a nd Structure s) Pa lett e
(Place items on the Block Diagram Window)
Structure:While Loop
• Recommended: Automatic Selection Tool• Tools to operate and modify both front panel and
block diagram objects
Operating Tool
Positioning/Resizing Tool
Labeling Tool
Wiring Tool
Tools Palette
Automatic Selection Tool
Automatically chooses among the following tools:
Run Button
Continuous Run Button
Abort Execution
Execution Highlighting Button
Additional Buttons on the Diagram Toolbar
Status Toolbar
Retain Wire Values Button
Step Function Buttons
Block Diagram Window
Front Panel Window
Demonstration 1: Creating a VI
InputTerminals
OutputTerminal
BooleanControl
GraphIndicator
• 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 output terminals when done
Da taf low Pro gr amming
Debugging Techniques• Finding Errors
• Execution Highlighting
• Probes
Click on broken Run button.Window showing error appears.
Click on Execution Highlighting button; data flow is animated using bubbles. Values are displayed on wires.
Right-click on wire to display probe and it shows data as it flows through wire segment.
You can also select Probe tool from Tools palette and click on wire.
Exercis e 2 – Acquiring a S ignal wit h DA QTrack A&BTrack A&B
This exercise should take 15 minutes.
• Use a LabVIEW template to:– Acquire a signal from your DAQ
device
Exercis e 2 – Acquiring a S ignal wit h th e S ound Card
Track CTrack C
• Use LabVIEW to:– Acquire a signal from your sound card
This exercise should take 15 minutes.
Co ntext Help Wi ndo w• Help»Sh ow Con text Help , press the <Ctrl+H> keys
• Hover cursor over object to update windowAdd i t ional He lp
– Right-Click on the VI icon and choose Help, or
– Choose “De tai le d Help.” on the context help window
Tips f or W or kin g in La bVI EW
• Keystroke Shortcuts– <Ctrl+H> – Activate/Deactivate Context Help Window– <Ctrl+B> – Remove Broken Wires From Block Diagram– <Ctrl+E> – Toggle Between Front Panel and Block
Diagram
– <Ctrl+Z> – Undo (Also in Edit Menu)
• Tools»Options… – Set Preferences in LabVIEW• VI Properties–Configure VI Appearance, Documentation, etc.
Sect io n I I – E le men ts of Typical Pro gra msA. Loops
• While Loop• For Loop
B. Functions and SubVIs• Types of Functions• Creating Custom Functions (SubVI)• Functions Palette & Searching
C. Decision Making and File IO• Case Structure• Select (simple If statement)• File I/O
Lo ops
•While Loops– i terminal counts iteration– Always runs at least once– Runs until stop condition is
met
• For Loops– i terminal counts iterations– Run according to input N of
count terminal
While LoopWhile Loop
For LoopFor Loop
Drawing a Loop
1. Select the structure
2. Enclose code to be repeated
3. Drop or drag additional nodes and then wire
3 Types of Fu nct io ns ( f rom t he Fu nct ions Palett e)Express VIs: interactive VIs with configurable dialog page (b lue b or de r)
Standard VIs: modularized VIs customized by wiring (cus tomizable)
Functions: fundamental operating elements of LabVIEW; no front panel or block diagram (ye l lo w)
What Type s of Fu nctions are Availab le?• Inpu t and O ut pu t
– Signal and Data Simulation– Acquire and Generate Real Signals with DAQ– Instrument I/O Assistant (Serial & GPIB)– ActiveX for communication with other programs
• Ana lys is – Signal Processing– Statistics– Advanced Math and Formulas– Continuous Time Solver
• Sto ra ge– File I/O
Express Functions Palette
Sea rc hing for Con trols, VI s, a nd Fun ction s• 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
Ex ercis e 2.1 – An alys is Track A,B,&CTrack A,B,&C
• Use LabVIEW Express VIs to:– Simulate a signal and display its amplitude and frequency
This exercise should take 15 minutes.
Ex ercis e 2.2 – An alys is Track A&BTrack A&B
• Use LabVIEW Express VIs to:– Acquire a signal and display its amplitude and frequency
This exercise should take 15 minutes.
Ex ercis e 2.2 – An alys is Track CTrack C
• Use LabVIEW Express VIs to:– Acquire a signal and display its amplitude and frequency
This exercise should take 15 minutes.
Ho w Do I Make De ci sion s in La bVIEW ?1. Case Structures
7. Select(a) (b)
(c )
File I /O
• File I/O – Allows recording or reading data in a file. • LabVIEW creates or uses the following file formats:
– Binary: underlying file format of all other file formats– ASCII: regular text files– LVM: LabVIEW measurement data file– TDM: created for National Instruments products
Hi gh Le vel File I/O Fu nct io ns
• Easy to use• High Level of abstraction
Writing to LVM fileWriting to LVM file Reading from LVM fileReading from LVM file
Exercis e 3.3 – Deci sion M ak ing and S av ing Dat a• Use a case structure to:
– Make a VI that saves data when a condition is met
This exercise should take 15 minutes.
Track A,B,CTrack A,B,C
File I/ O Pro gr amming Mo del – U nd er t he hood
Ope n/Cre at e/
Re plac e F i le
Rea d and/ or
Wr i te t o File
Cl ose File
Che ck forEr ro rs
Spr ead sheet Form at tin g
• Spreadsheet files are ASCII files with a certain formatting– Usually tabs between columns and end of line constants
between rows– LabVIEW includes VIs that perform this formatting or a string
can be concatenated
Sect io n I II – Pre senting your Re sul tsA. Displaying Data on the Front Panel
• Controls and Indicators• Graphs and Charts• Loop Timing
B. Signal Processing• MathScript• Arrays• Clusters• Waveforms
What Types of Con trols and In di cat ors are Available?• Numer ic Dat a
– Number input and display– Analog Sliders, Dials, and Gauges
• Boolean Da ta– Buttons and LEDs
• Array & Mat ri x Da ta– Numeric Display– Chart– Graph– XY Graph– Intensity Graph– 3D graph: point, surface, and model
• Dec or at ions– Tab Control– Arrows
• Other– Strings and text boxes– Picture/Image Display– ActiveX Controls
Express Controls Palette
Cha rts – A dd 1 d ata point at a t im e wit h historyWaveform chart – special numeric indicator that can display a history of values
• Chart updates with each individual point it receives
Functions»Express»Graph Indicators»Chart
Graph s – Dis play ma ny data poin ts at onc eWaveform graph – special numeric indicator that displays an array of data
• Graph updates after all points have been collected• May be used in a loop if VI collects buffers of data
Functions»Express»Graph Indicators»Graph
• Loops can accumulate arrays at their boundaries with auto-indexing
• For Loops auto-index by default
• While Loops output only the final value by default
• Right-click tunnel and enable/disable auto-indexing
Build ing Arr ay s with Lo op s (Auto-Inde xin g)
Wire becomes thicker
Wire remains the same size
Aut o-Indexing Dis abl ed
Auto-I ndexing Enabl ed
Only one value (last iteration) is passed out of the loop
1D Array
0 1 2 3 4 5
5
Cr ea t in g an Arr ay (St ep 1 of 2)From the Controls»Modern»Array, Matrix, and Cluster subpalette, select the Array icon.
Drop it on the Front Panel.
Cr ea te an Arra y (Step 2 o f 2)1. Place an Array Shell.
2. Insert datatype into the shell (i.e. Numeric Control).
Ho w Do I Time a Lo op ?1. Loop Time Delay
• Configure the Time Delay Express VI for seconds to wait each iteration of the loop (works on For and While loops).
2. Timed Loops• Configure special timed While loop for desired dt.
Timed LoopTime Delay
Co ntro l & I ndicator Pro pe rt ies• 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:– Cursors– Scaling
Ex ercis e 3.1 – Ma nua l An alys is Track A,B,&CTrack A,B,&C
• Use the cursor legend on a graph to:– Verify your frequency and amplitude measurements
This exercise should take 15 minutes.
Textual Math in La bVIE W• 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, whether
graphical or textual within one VI
Su pp or ted M ath Too ls :MathScript script node MathSoft softwareMathematica software MATLAB® softwareMaple software Xmath software
MATLAB ® is a registered trademark of The MathWorks, Inc.
Math w it h the Math Scrip t N ode• 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 Mat hS cript W indo w.
(F unc t ions»P rogram ming »Structures »Mat hSc ri pt)
The Inter act ive MathScrip t W in dow• Rapidly develop and test algorithms
(LabV IEW»Tools »Math Scr ipt Window )
Out putWind ow
Va ria bleWo rk spac
e
View/ Mod ifyVar iable
Co nte ntsUser
Commandsm-f il e Sc ri pt
• Share Scripts and Variables with the Node
• View /Modify Variable content in 1D, 2D, and 3D
Ex ercis e 3.2 – Using MathScrip tUse the MathScript Node and Interactive Window to process the acquired signal (logarithmic decay) in the MathScript and save the script.
Track A,B,&CTrack A,B,&C
This exercise should take 25 minutes.
Exerc is e 3.3 – A ppl y What Yo u Hav e LearnedTrack A,B,&CTrack A,B,&C
This exercise should take 20 minutes.
Sect io n I V – A ddition al Lab VI EW Top ic s
A. Additional Data types• Cluster
B. Data Flow Constructs• Shift Register
C. SubVIs
D. State Machines
E. Local Variables
F. Producer/Consumer
Int rod uct io n t o 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
Cr ea t in g a Clu ster• Select a Cl ust er shell.
Contro ls »M odern»Arra y, Matr ix & Cluste r
2. Place objects inside the shell.
Cl us te r F unct ions• In the Cluster & Variant subpalette of the
Programming palette• Can also be accessed by right-clicking the cluster
terminal
Bundle
(Terminal labels reflect data type)
Bundle By Name
Using A rra ys and Clust ers wit h G ra phs
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 t ime) Cluster (relat iv e ti me)
Shift Register – Access Previous Loop Data• Available at left or right border of loop structures• Right-click the border and select Ad d Sh if t Re gis ter • Right terminal stores data on completion of iteration• Left terminal provides stored data at beginning of next iteration
Before Loop
BeginsFirst
IterationSecondIteration
LastIteration
Val ue 3Ini t ia lVa lu e
Mod ula rity in La bVI EW – Sub VI s
Convert repeated functions and VIs with a single VI
Crea te Su bVI• Enclose area to be converted into a subVI.
• Select Edit» Create S ubVI from the Edit Menu.
LabVIEW Functions and SubVIs operate like Functions in other languages
Fu nct ion Ps eudo Co defunction average (in1, in2,
out){out = (in1 + in2)/2.0;}
Su bV I Bl ock Dia gr am
Ca l li ng Pr og ra m P se udo Co de
main{average (in1, in2, pointavg)}
Ca l li ng VI Bl ock Diag ra m
Ic on and Con nector Pan e
• Use this connector pane layout as a standard
• Top terminals are usually reserved for references, such as a file reference• Bottom terminals are
usually reserved for error clusters
Ic on and Con nector Pan e – Cr ea te Ic on
• Create custom icons by right-clicking the icon in the upper right corner of the front panel or block diagram and selecting Ed it Ic on or by double-clicking the icon
• You also can drag a graphic from anywhere in your file system and drop it on the icon
• Refer to the Icon Art Glossary at ni.com for standard graphics to use in a VI icon
St ate Ma chine s Tra nsit io ns
• Several programming techniques exist for transitioning from state to state in LabVIEW using State Machines
• Default transition implies that after one state, another state always follows
• Transitions between two potential states can be handled by a Select Function
Co mmun ic at in g betw ee n l oop s•Communicating between loops using data flow is not possible
•The left loop will execute completely before the right loop
•Variables are needed when communication with wires does not give the desired behavior
Local Variables• Local Variables allow data to be passed between parallel loops.• A single control or indicator can be read or written to from more than one location in the program
– Local Variables break the dataflow paradigm and should be used sparingly
Crea ting a Local Variable - Walk Throu gh
In this example we will see how Local Variables allow us to share data between parallel loops. We will create a program that toggles two separate LEDs using one switch. It also stops two loops with one button.
Create the block diagram and front panel as seen to the right.
Cr ea t in g Loca l Var iab les
Right-click on the Stop Button in the Front Panel and change the Mechanical Action to “Switch When Released” since Local Variables cannot store Latched data.
V. La rg e Pr og ram D evelop ment
A. Navigation Window
B. LabVIEW Project
C. Shared Variable
• Shows the current region of view compared to entire Front Panel or Block Diagram
• Great for large programs
La bVI EW Naviga t io n W in dow
* Organize and reduce program visual size with subVIs
La bVI EW Pr oject
• Group and organize VIs• Hardware and I/O management• Manage VIs for multiple targets• Build libraries and executables• Manage large LabVIEW applications• Enable version tracking and management
(Lab VI EW» Pr ojec t»Ne w)
Sha red Va riab les
• Shared Variables are used to send data between VIs. • Variable Types:
– Single Process: share the data among VIs on the local computer.– Network-published: communicate between VIs, remote
computers, and hardware through the Shared Variable Engine.
• Shared Variable must exist within a project library.• Shared Variable must be deployed to be available to other projects
and remote computers.
Sect io n V I - I nstru men t Co ntro l
A. Overview of Instrument Control
B. GPIB
C. Serial
D. Instrument I/O Assistant
E. VISA
F. Instrument Drivers and IDNET
Wha t Types of I ns trum ents Can Be Con trolled?
• GPIB• Serial• Modular Instruments• PXI Modular Instruments• Image Acquisition• Motion Control• USB• Ethernet• Parallel Port• CAN
GPI B
• General Purpose Interface Bus (GPIB)• GPIB is usually used in stand alone bench top instruments to control measurements and communicate data
• Digital 8-bit parallel communication interface• IEEE 488.1 and 488.2 define standards for GPIB
Ser ial
• Serial communication transmits one bit at a time over a transmission line
• Usually does not require external hardware• Four parameters: baud rate, data bits, parity bit, stop bits
Inst rumen t I/ O As sist ant
• LabVIEW Express VI used to communicate with message-based instruments
• Communicate with an instrument that uses a serial, Ethernet, or GPIB interface
• Use the Instrument I/O Assistant when an instrument driver is not available
VI SA
• Virtual Instrumentation Software Architecture (VISA)• High-level API that calls low-level drivers• Can control VXI, GPIB, serial, or computer-based instruments
• Makes appropriate driver calls depending on the instrument used.
Inst rumen t D rivers
• Plug and Play drivers are a set of VIs that control a programmable instrument
• VIs correspond to instrument operation: configuring, triggering, and reading measurements
• Help getting started since programming protocol for each instrument is already known
IDN ET
• Instrument Driver Network (IDNET)• Instrument Driver Finder within LabVIEW
To ols » In str um ent ation » Find In str um en t Dr ivers
He lp » Find I nst ru men t Driv ers
• Can be found online at www.ni.com/idnet
Add itio nal R es our ces• 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 Edition– www.ni.com/academic By Robert H Bishop.
Published by Prentice Hall. Updat ed f or
LabVIEW 8
Th e LabVIEW Ce rtif ic at io n Pro gra m
Ce rtifie d L ab VIEW De velop er
Certifie d L abVIEW Asso ciat e De velo pe r
Certified LabVI EW Ar ch itec t
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 application development experience
Fundam ental s Ex am•Pre-Certification Skills Test Fr ee O n-L ine Fu ndamen tals Fr ee O n-L ine Fu ndamen tals
Exa mExa m
Elect roni cs Wor kbench an d Multis im
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• Low cost student editions available• www.electronicsworkbench.com
Multisim Integ rated wit h Lab VIEW1. Create Schematic 2. Virtual Breadboard 3. Simulate
4. PCB Layout 5. Test 6. Compare
You r Next Step …
Take the free LabVIEW Fundamentals Exam at ni.com/academic
Your first step to become LabVIEW Certified!