LabVIEW/DAQ by Dr. M. Kostic LabVIEW - DAQ Data Acquisition Dr. M. Kostic NIU - Mechanical Engineering

LabVIEW/DAQ by Dr. M. Kostic

LabVIEW - DAQ LabVIEW - DAQ Data AcquisitionData Acquisition

Dr. M. Kostic

NIU - Mechanical Engineering


What is LabVIEW - GWhat is LabVIEW - G

VVirtual IInstrumentnstrument EEngineering WWorkbench Full-featured Graphical Programming Software Designed for Instrumentation and Data

Acquisition

Watch NI Demo


What is Virtual Instrument-VIWhat is Virtual Instrument-VI

A software designed program to simulate an instrument (Virtual Instrument)

Versatile as our creativity It is stored in a file any_name.vi extension It could be used as a subroutine or main

program


Virtual Instruments (VIs)Virtual Instruments (VIs)• Front PanelFront Panel– Controls = Inputs

– Indicators = OutputsInputInput OutputOutput

• BlockBlock DiagramDiagram– Accompanying

"program" for front panel

– Components "wired" together


(sub) VI as an Icon(sub) VI as an Icon

LV Basics 12 Mar 94

Creating the IconIcon/Subroutine

• Pop up in the icon pane

• It is recommended to create black and white icon


Let’s Let’s switchswitch to LabVIEW to LabVIEW software software and playand play........

Show some ExamplesShow some Examples......


Lab VIEW SummaryLab VIEW Summary Virtual Instruments (VIs)Virtual Instruments (VIs)

Front Panel Block Diagram Connector/Icon

Two windows to create a VITwo windows to create a VI Panel window (I/O) Diagram window (Program)

Pull-down menusPull-down menusControls menu to place controls/indicators (I/O) in Panel

window

Functions menu to place program nodes in Diagram window

All LabVIEW objects have pop-up menusAll LabVIEW objects have pop-up menus Nonexecutable VIs indicated by...Nonexecutable VIs indicated by...


DAQDAQor

Data AcquisitionData Acquisition


About plug-in data acquisition (DAQ) boards.About plug-in data acquisition (DAQ) boards. About the organization of the DAQ VIs.About the organization of the DAQ VIs. How to acquire and display an analog signal.How to acquire and display an analog signal. How to perform a timed data acquisition.How to perform a timed data acquisition. How to acquire data from multiple analog How to acquire data from multiple analog

channels.channels. How to drive the digital I/O lines, and the How to drive the digital I/O lines, and the

basics of buffered data acquisition.basics of buffered data acquisition.

DAQ ScopeDAQ Scope


DAQ boards:DAQ boards:Analog I/ODigital I/OCounter/timer I/O

DAQ library supports all DAQ boards DAQ library supports all DAQ boards LabVIEW uses the NI-DAQ driver-level softwareLabVIEW uses the NI-DAQ driver-level software

Data Acquisition System ComponentsData Acquisition System Components

PLUG-IN DAQ BOARD: PLUG-IN DAQ BOARD: Measures (acquires), processes, stores, and generates signals, as instructed by software program. Examples: Analog and digital

signals’ input and output, counters, timers, etc.

COMPUTER with SOFTWARE:COMPUTER with SOFTWARE: Control the DAQ board, process, store, and display data, as instructed by software

program. Examples: LabVIEW application programs to acquiredata, simulate instruments, and generate results, etc.

SIGNAL CONDITIONING: SIGNAL CONDITIONING: Modify transducer signals to match DAQ board specs/ranges. Examples: amplification

or attenuation, filtering, excitation, etc.

TRANSDUCERS: TRANSDUCERS: Sense the measured quantitiesand change their properties or generate corresponding electrical signals. Examples: strain gage, thermocouple,

accelerometer, potentiometer, etc.

Data Acquisition - DAQData Acquisition - DAQ


TransducersTransducers

Sense Phenomena

Produce Electrical Signal

Examples: Thermocouples, ThermistorsThermocouples, Thermistors Strain Gauges, RTDsStrain Gauges, RTDs Pressure Transducers, Load CellsPressure Transducers, Load Cells Accellerometers, MicrophonesAccellerometers, Microphones Potentiometers, Etc..Potentiometers, Etc..


Signal ConditioningSignal ConditioningCondition Transducer Signals

Make Signal Suitable for DAQ Board

Examples: Amplification/AttenuationAmplification/Attenuation Linearization/CalibrationLinearization/Calibration FilteringFiltering Multiplexing (up to 3,072 channels)Multiplexing (up to 3,072 channels) Isolation, Excitations, Etc.Isolation, Excitations, Etc.


Typical DAQ BoardTypical DAQ BoardMain Features:

Analog I/O (Input/Output) Digital I/O Timer/Counter I/O, Triggering Accuracy, Flexibility, Reliability, Expandability

Typical Specifications: Computer Platform: (E)ISA, PCMCIA, PCI, NuBus Input Channels: 8-16 SEnd, 4-8 DIff Max. Sampling Rate: 50-500 (1,250) kHz Resolution: 8-16 bits Gains: 1,2,5,10,20,50,100 Times Range:2.5) 5, (0-5)0-10 Volt


DAQ Hardware & SoftwareDAQ Hardware & Software

ConfigurationsConfigurationsHardware:

Setting DIP Switches and Jumpers for Particular Options/Applications

Newer and Plug-and-Play Boards are Software Configured

Cabling, Signal Conditioning, Terminal Blocks, etc.

Software: Set-up and Configuration Programs Drivers: Interface between DAQ Board and Computer DAQ Application Software (LabVIEW, C, Basic, etc.)

Data AcquisitionData Acquisition Data Analysis (Statistics, FFT, DSP, etc.)Data Analysis (Statistics, FFT, DSP, etc.) Data PresentationData Presentation (Graphing, Plotting, Tabulation, etc.)(Graphing, Plotting, Tabulation, etc.)


Analog Input ConsiderationsAnalog Input Considerations• Single-Ended vs. DifferentialSingle-Ended vs. Differential

• • ResolutionResolution

• RangeRange

• Sampling Rate / AliasingSampling Rate / Aliasing

• Averaging / Noise reductionAveraging / Noise reduction

10

1 * 212= 2.4 mV

20

1 * 212= 4.8 mV

Adequately sampled

Aliased due to undersampling

8

3-bit ADC 16-bit ADC

Time

.

10 V range

12 bitresolution

1X Gain

Aliasing

.


DAQ Software Architecture – WindowsDAQ Software Architecture – Windows

WDAQCONF.EXE LabVIEW for Windows

DAQ Library VIs

DAQDRVNI-DAQ for Windows

DLL

WDAQCONF.EXE

DAQ BoardNow, new operating systemsand application software versions

make CONFIGURATION ESEAR!


Analog Input and Output VIsAnalog Input and Output VIs

AI Sample ChannelAI Sample Channel

AO Update ChannelAO Update Channel


Waveform Input and Output VIsWaveform Input and Output VIs

AI Acquire WaveformAI Acquire Waveform

AOAO GenerateGenerate WaveformWaveform


Digital Input and OutputDigital Input and Output

Write to Digital LineWrite to Digital Line ReadRead fromfrom DigitalDigital LineLine

WriteWrite toto DigitalDigital PortPort ReadRead fromfrom DigitalDigital PortPort


DAQ SummaryDAQ Summary

Identify I/O Signal Types: Identify I/O Signal Types: Transducers/ControllersTransducers/Controllers

Choose a Signal Conditioning MethodChoose a Signal Conditioning Method Select a Data Acquisition (DAQ) DeviceSelect a Data Acquisition (DAQ) Device Choose Terminals/Cables for the HardwareChoose Terminals/Cables for the Hardware Select DAQ SoftwareSelect DAQ Software

© MCMXCIX* Prof. M. Kosticwww.kostic.niu.edu

The Art of The Art of Signal Sampling and Aliasing:Signal Sampling and Aliasing:

Simulation with a LabVIEWSimulation with a LabVIEW™™ Virtual Instrument Virtual Instrument

""What We See is Not What It Is!What We See is Not What It Is!""

Prof. M. KosticProf. M. Kostic Mechanical EngineeringMechanical Engineering

NORTHERN ILLINOIS UNIVERSITYNORTHERN ILLINOIS UNIVERSITY


W.W.S.W.W.S.N.N.W.I.I.W.I.I. ""What We See What We See is Notis Not What It Is! What It Is!""

It’s all about ...It’s all about ...… … Sampling and AliasingSampling and Aliasing!!

Even ...Even ...W.Y.S.W.Y.G.W.Y.S.W.Y.G. ""What You See is What You Get!What You See is What You Get!””

……is REALLY NOT true (the same)is REALLY NOT true (the same) on different Monitors and Printerson different Monitors and Printers


Signal/Sampling ResolutionSignal/Sampling Resolution

SamplingSampling//Time Resolution Time Resolution ((SpeedSpeed))

Sig

nal

Sig

nal

// Mag

nit

ud

e M

agn

itu

de

Res

olu

tion

Res

olu

tion


There is NOThere is NOsuch thing as...such thing as...……too large hard drive disk, too large hard drive disk, or ...or ...……too large sampling resolutiontoo large sampling resolution!!

Well praised ... Well praised ... high-definition digital graphicshigh-definition digital graphicsand CD-quality musicand CD-quality music

……are NOT good (true) enoughare NOT good (true) enough!!


• Under-sampling looses Under-sampling looses (important) wave details(important) wave details !!

• But it also may change the wave But it also may change the wave form/shape due to Aliasing form/shape due to Aliasing !!

((UnderUnder))Sampling & Aliasing ...Sampling & Aliasing ...


Real measurements Real measurements of a simple sine-harmonicof a simple sine-harmonic

How come this if the measured signalis a simple sine-harmonic wave?


Sampled signal

Real signal


Sampled signal

Real signal


Sampled signal

Real signal


Stroboscope light Rotating disk(RPM)

Sampling RPM with StroboscopeSampling RPM with Stroboscope

If RPM and Strobe speeds(frequencies) are the same

the reference mark willappear stationary (ZERO aliasing)

If the Strobe speed is fasterIf the Strobe speed is slower

If the Strobe speeds ishalf of RPM, the disk willturn twice and the mark

will appear stationary again!


NO

Ali

as. Aliasing

ZEROAliasing


Interactive Experiments ...Interactive Experiments ...

LabVIEW Virtual InstrumentsLabVIEW Virtual Instruments

Internet Interactive ExperimentInternet Interactive Experiment

Animated MovieAnimated Movie


Who does the future belongs to ?Who does the future belongs to ?


No Limits …No Limits …

The Future The Future Belongs Belongs

To…To…

… … Whoever Whoever Gets There Gets There

FirstFirst

NOSPEED

LIMIT

Prof. Prof. M. KosticM. Kostic Mechanical EngineeringMechanical Engineering

NORTHERN ILLINOIS UNIVERSITYNORTHERN ILLINOIS UNIVERSITY

Instrumentation with Instrumentation with Computerized Data Computerized Data AcquisitionAcquisition for an for an Innovative Thermal Innovative Thermal Conductivity ApparatusConductivity Apparatus

IntroductionIntroductionWhich teaching/learning method is better…Which teaching/learning method is better…

theoretical vs. experimental,theoretical vs. experimental,...traditional vs. new-tech aided, ...traditional vs. new-tech aided, ...inductive vs. deductive…?...inductive vs. deductive…?

It’s like…which cold-medicine is the best…It’s like…which cold-medicine is the best…… “chicken or egg, which one came … “chicken or egg, which one came first”…?first”…?

There is NO the best…There is NO the best………”right-mixture” of all…is the best”right-mixture” of all…is the best!!

Introduction Introduction (Cont’d)(Cont’d)

This research application... This research application... ......looks complexlooks complex for undergraduates for undergraduates

But, simple and “in-principle” examplesBut, simple and “in-principle” examples...are ...are not enoughnot enough for good for good professional trainingprofessional training

Goal...Goal......To ...To work in-depthwork in-depth a “nice” complex a “nice” complex applicationapplication

Introduction Introduction (Cont’d)(Cont’d)

Computerized Computerized data acquisition data acquisition hardwarehardware and and LabVIEWLabVIEW development and application development and application software software ......in engineering curriculumin engineering curriculum at NIU at NIU ...starting with Experimental Methods I ...starting with Experimental Methods I and II ME coursesand II ME courses

ObjectivesObjectives

In addition to basics instrumentation, In addition to basics instrumentation, measurements...measurements...

...show students a purposeful, ...show students a purposeful, complex applicationcomplex application

……which was a real professional which was a real professional funded project, andfunded project, and

……which employs Computerized (“On-which employs Computerized (“On-Line”) Data AcquisitionLine”) Data Acquisition

Objectives Objectives (Cont’d)(Cont’d)

To demonstrate, analyze and discuss:To demonstrate, analyze and discuss:

•Engineering challenge -What is to be Engineering challenge -What is to be accomplished?accomplished?

•Mechanical and Electrical DesignMechanical and Electrical Design

•Instrumentation and MeasurementsInstrumentation and Measurements

•Computerization and Data AcquisitionComputerization and Data Acquisition

Engineering challengeEngineering challenge:: What is to be What is to be accomplished accomplished ??

•An innovative method and a novel An innovative method and a novel research apparatusresearch apparatus

• to measure the to measure the thermal conductivitythermal conductivity of a non-Newtonian fluid of a non-Newtonian fluid while it is while it is subjected to shearing flowsubjected to shearing flow, and, and

• to determine its dependence, if any, on to determine its dependence, if any, on shearing itself. shearing itself.

Engineering challenge Engineering challenge (Cont’d)(Cont’d)

This is This is contrary to the current state-of-contrary to the current state-of-the-artthe-art of measuring thermal conductivity of measuring thermal conductivity under the condition of motionless fluid,under the condition of motionless fluid,...to avoid convective heat transfer ...to avoid convective heat transfer influence on the results. influence on the results.

Mechanical and Electrical DesignMechanical and Electrical DesignTC ApparatusTC Apparatus

The main test-The main test-section section dimensions:dimensions:

• D/d=D/d=2.598/ 2.488 2.598/ 2.488 inin outer/inner outer/inner cylindercylinder diameters diameters respectively respectively

• with the with the 0.055 0.055 inin thick gapthick gap, filled , filled with the test-fluid with the test-fluid in-betweenin-between

Mechanical and Electrical Mechanical and Electrical Design Design (Cont’d)(Cont’d)

Main and Guard HeatersMain and Guard Heaters

Outer CylinderOuter CylinderInner CylinderInner Cylinder

Bearing withBearing with

Dynamic SealDynamic Seal

Instrumentation Instrumentation and and MeasurementsMeasurements 16 Thermocouples16 Thermocouples

DC voltage dropDC voltage drop (across the main heater (across the main heater and a precise current and a precise current resistor resistor for power for power meas.meas.))

Set & control guard Set & control guard heatingheating (Solid-state (Solid-state Relays)Relays)

Set & control cylinder Set & control cylinder rotational speedrotational speed(motor drive and (motor drive and

tachometer-sensor)tachometer-sensor)

11

22

44

33

22

11

33

33

44

Instrumentation Instrumentation and and MeasurementsMeasurements (Cont’d)(Cont’d) AT-MIO-16DE-10 data AT-MIO-16DE-10 data

acquisition boardacquisition board

SCXI-1000 4-slot signal SCXI-1000 4-slot signal conditioning chassisconditioning chassis

SCXI-1122 16-channel SCXI-1122 16-channel multiplexer-signal multiplexer-signal conditioning module for conditioning module for thermocouples thermocouples

SCXI-1322 shielded SCXI-1322 shielded terminal block (w/ CJC) terminal block (w/ CJC)

SCXI-1353 shielded SCXI-1353 shielded cable assemblycable assembly

Two CB-50 terminal Two CB-50 terminal blocks with NB-1 blocks with NB-1 extensionsextensions

11

22

3344

5566

11

11

22

33

44

55

66

AT-MIO-16DE-10AT-MIO-16DE-10Data Acquisition BoardData Acquisition BoardE Series architectureE Series architecture

•Up to 100 kSamples/sec Up to 100 kSamples/sec

•16 single-ended/8 differential 16 single-ended/8 differential channels, 12-bit channels, 12-bit analog inputsanalog inputs

• two 12-bit two 12-bit analog outputsanalog outputs

•32 32 digital I/Odigital I/O channels channels

• two 24-bit, 20 MHz two 24-bit, 20 MHz counter/timerscounter/timers

Computerization and Computerization and Data AcquisitionData Acquisition

• feed-back control for feed-back control for DC motor-DC motor-drivedrive using a calibrated using a calibrated tachometer-sensortachometer-sensor

• solid-state relays for efficient and solid-state relays for efficient and accurate feed-back control of accurate feed-back control of guard-heaters’ powerguard-heaters’ power

• comprehensive comprehensive over-heating over-heating protectionprotection

• interactive and comprehensive interactive and comprehensive monitoring for the monitoring for the kinematics kinematics and thermal steadinessand thermal steadiness of all of all processes and processes and

• convenience of increasing the convenience of increasing the number of thermocouple sensors number of thermocouple sensors for for more advanced more advanced measurementsmeasurements

Computerization and Data Acquisition Computerization and Data Acquisition (Cont’d)(Cont’d)

ConclusionConclusion•One of the objectivesOne of the objectives

...to utilize the latest powerful, yet ...to utilize the latest powerful, yet inexpensive, technological developments: inexpensive, technological developments: sensors and transducers, sensors and transducers,

•data acquisition and control integrated data acquisition and control integrated boards, boards,

•computers and application software, computers and application software,

......for research and teaching by examplefor research and teaching by example. .

Conclusion Conclusion (Cont’d)(Cont’d)

The designed, computerized measurement The designed, computerized measurement and data acquisition system, and data acquisition system, accomplishes the following objectives: accomplishes the following objectives:

acquire measured data with acquire measured data with high speed and accuracyhigh speed and accuracy

interactively process and analyzeinteractively process and analyze measured data for measured data for immediate use or future post-processing immediate use or future post-processing

provide provide interactive and accurate feed-backinteractive and accurate feed-back process process control - motor speed and guard-heating power, andcontrol - motor speed and guard-heating power, and

interactively displaysinteractively displays the raw/measured and the raw/measured and processed/analyzed data in graphical and/or numerical processed/analyzed data in graphical and/or numerical formsforms


In addition this system allows for...In addition this system allows for...

easy modification and enhancementeasy modification and enhancementof so called of so called ““virtualvirtual (software) (software) instrumentsinstruments””...by modification of software ...by modification of software programs.programs.


Will NewTech replace/endanger Will NewTech replace/endanger traditional values, humans? - Definitely traditional values, humans? - Definitely NOT! NOT! Should we use NewTech to our benefits - Should we use NewTech to our benefits - Definitely YES!Definitely YES!

Remember, the TV has never Remember, the TV has never endangered Printed Press; the both endangered Printed Press; the both have been enhancing each other!have been enhancing each other!

We do not have to change, but we have We do not have to change, but we have to adopt to changes (NewTech to adopt to changes (NewTech including)!including)!


•New-TechNew-Technologynology developments developments...maturity, critical mass, wide use...maturity, critical mass, wide useprovide for new waysprovide for new ways to improve to improve engineering curriculum and engineering curriculum and enhance learningenhance learning environment environment

•Either Either lack of use, or abuselack of use, or abuse of modern of modern technological and computational toolstechnological and computational tools

•NewTech should be our Slave, NOT our NewTech should be our Slave, NOT our Master.Master.


"Location, Location, and Location!" "Location, Location, and Location!" …as Realtors said.…as Realtors said.

"Access, Access, and Access!", "Access, Access, and Access!", …as Internet nerds said.…as Internet nerds said.

"Time, Time, and Time!", "Time, Time, and Time!", …as Businessmen said.…as Businessmen said.

"Quality, Quality, and Quality!”"Quality, Quality, and Quality!” …as it really matters.…as it really matters.

AcknowledgmentAcknowledgment• National Science Foundation support National Science Foundation support

(Grant No. CTS-9523519). (Grant No. CTS-9523519).

• Graduate School of Northern Illinois Graduate School of Northern Illinois University (NIU)University (NIU)

• Department of Mechanical EngineeringDepartment of Mechanical Engineering

• Mr. Haibo Tong, graduate student and Mr. Haibo Tong, graduate student and Mr. Al Metzger, for mechanical design and Mr. Al Metzger, for mechanical design and fabrication fabrication

• Mr. Bill Vickers, for electronics design and Mr. Bill Vickers, for electronics design and fabricationfabrication

You may contact Prof. Kostic You may contact Prof. Kostic at:at:

mailto: mailto: [email protected]@niu.edu

or on the Web:or on the Web:

http://http://www.kostic.niu.eduwww.kostic.niu.edu

Documents

LabVIEW/DAQ by Dr. M. Kostic LabVIEW - DAQ Data Acquisition Dr. M. Kostic NIU - Mechanical Engineering