wireless data acquisition in labviewhome.hit.no/~hansha/documents/labview/training/wireless...

UniversityCollegeofSoutheastNorway

http://home.hit.no/~hansha

WirelessDataAcquisitioninLabVIEW

Hans-PetterHalvorsen,2016.10.31

ii

PrefaceIt'snotjustphonesandcomputersthatcancommunicatewirelesslywiththeoutsideworld.Wirelesssensorsappearbothinmedicine,inbuildingsandespeciallyinindustrialapplications.

Itisdevelopedmorestandardizedradionetworkforwirelesssensors.Zigbeeisprobablythemostfamous,wheremorethan300largeandsmallcompaniesworkingtodevelopsolutions.Forindustrialuserequiresspecialsafetyrequirements.Radionetworkmusthavesufficientcoveragetoobtainanacceptableerrorrate.Thenetworkshouldhaveredundancysothattherandomoutcomecanberepairedautomatically.Itisachievedinthatmessagescangoseveralwaysfromthesensorstothecenters.Also,thenetworkforerrorhandlinganderrorcorrectionsothatrandomerrorsarecorrected.BecauseoftheserequirementsithasbeenshownthatZigBeeisnotalwayssuitableforuseintheindustrialcontext.Thisparticularlyappliesitinprocesscontrol,whereresistancetoelectromagneticnoiseandencryptionofthesignalsisimportant.

AwirelessstandardspecificallydesignedtosatisfyindustrialrequirementsisWirelessHART.ThisisbasedonthesamephysicalradiotechnologysuchasZigBee,butspecifiesadditionalfrequencyhoppingtomitigateinterference,betterencryptionandthatprovidesforlowerpowerconsumption.

Currently,thewirelesssensorshavebeenusedformonitoring,whereahumanoperatormustdecidewhethertheprocessparametersshouldbechangedornot.Theobjectiveisthatthetechnologywillprovetoberobustenoughtoalsobeusedtoprocesscontrolwherethechangesintheindustrialprocessesshouldhappenautomaticallywithouthumanintervention.Thiswillbethenextmajorchallengeforsystemsbasedonwirelesstechnology.

Wirelesstechnologyhasmanypotentialbenefitsforremotemonitoringapplications;however,ithasbeenslowtoseeadoptioninindustrybecauseofthecomplexitiesofprogramminganddeployingareliable,secure,andhigh-performancewirelesssystem.NIWi-Fidataacquisition(DAQ)devicesmeetthesechallengesbycombiningIEEE802.11wirelessorEthernetcommunication,directsensorconnectivity,andtheflexibilityofNILabVIEWsoftware.

SomeApplicationAreasforWirelesstechnologysuchasWi-Fimonitoring:


Challengeswithwirelessdataacquisitiontechnology:

• Proprietaryprotocolsandnetworkhardware• IncompleteI/Oofferings• High-speedwaveformmeasurements• Lackofinteroperabilitybetweensuppliers• Integrationwithexistingwiredsystems• Non-standardvendor-definedsolutions

NationalInstruments(NI),thevendoroftheLabVIEWprogrammingenvironmentdeliversseveralsolutionsforwirelessmonitoringanddataacquisition.

NIWi-Fidataacquisition(NIWi-FiDAQ)devicescombineIEEE802.11b/gwirelessorEthernetcommunication,directsensorconnectivity,andtheflexibilityofNI-DAQmxsoftwareforremotemonitoringofelectrical,physical,mechanical,andacousticsignals


Thisdocumentintroduceswirelessdataacquisitionfeaturesandteachesyouhowyoucansimplifywirelessremotemeasurementswithoutcompromisingonthesecurityorperformanceofacableddataacquisitionsolution.

v

TableofContentsPreface......................................................................................................................................ii

TableofContents......................................................................................................................v

1 WirelessTechnology.........................................................................................................1

1.1 Bluetooth....................................................................................................................2

1.2 WirelessUSB...............................................................................................................3

1.3 ZigBee(IEEE802.15.4)................................................................................................4

1.4 Wi-Fi(IEEE802.11)......................................................................................................5

2 WirelessSensorNetwork(WSN).......................................................................................1

2.1 WirelessStandards.....................................................................................................1

2.1.1 ZigBee(IEEE802.15.4).........................................................................................2

2.1.2 IEEE802.11..........................................................................................................3

2.1.3 WirelessHART......................................................................................................3

2.2 WirelessMeshNetwork(WMN).................................................................................4

3 IntroductiontoLabVIEW...................................................................................................6

3.1 Dataflowprogramming...............................................................................................6

3.2 Graphicalprogramming..............................................................................................6

3.3 Benefits.......................................................................................................................7

4 IntroductiontoDataAcquisition(DAQ)............................................................................8

4.1 IntroductiontoDAQ-DataAcquisition......................................................................8

4.1.1 Physicalinput/outputsignals..............................................................................9

4.1.2 DAQdevice/hardware.........................................................................................9

4.1.3 Driversoftware..................................................................................................10

4.1.4 Yoursoftwareapplication(Applicationsoftware).............................................11

vi TableofContents

Tutorial: Wireless Data Acquisition in LabVIEW

4.2 MAX–MeasurementandAutomationExplorer......................................................11

4.3 NI-DAQmx.................................................................................................................12

4.3.1 DAQAssistant....................................................................................................13

5 IntroductiontoWirelessDataAcquisition......................................................................14

6 NIWirelessDAQDevices.................................................................................................17

6.1 NIWLS-9234.............................................................................................................18

6.2 NIWAP-3701............................................................................................................19

6.3 NIUES-3880..............................................................................................................20

6.4 PS-5PowerSupply....................................................................................................21

7 NIWSNDevices...............................................................................................................22

7.1 Devices......................................................................................................................24

7.1.1 NIWSN-9791-WSNEthernetGateway............................................................24

7.1.2 NIWSN-3212-ThermocoupleInputNode........................................................24

7.1.3 NIWSN-3202-AnalogInputNode....................................................................25

7.2 LabVIEWDrivers.......................................................................................................25

1

1 WirelessTechnologyWirelesstechnologyandwirelessnetworksarewidelyusedtoday,butit’squitenewinindustrialautomationsystems.

[www.ni.com]

Therearedifferenttechnologiesandwirelessstandardsavailable:

• Bluetooth• WirelessUSB• ZigBee(IEEE802.15.4)• Wi-Fi(IEEE802.11)

2 WirelessTechnology


Differentwirelesstechnologies:

[www.ni.com]

TheFigurebelowcomparethedifferentwirelesstechnologies:

[www.ni.com]

Wi-FiandZigBeearetheprimarywirelesstechnologiesformeasurementandcontrolsystems.

1.1 Bluetooth



[www.ni.com]

1.2 WirelessUSB

[www.ni.com]



1.3 ZigBee(IEEE802.15.4)

[www.ni.com]

[www.ni.com]



1.4 Wi-Fi(IEEE802.11)

[www.ni.com]

1

2 WirelessSensorNetwork(WSN)Source:www.wikipedia.org

Awirelesssensornetwork(WSN)consistsofspatiallydistributedautonomoussensorstocooperativelymonitorphysicalorenvironmentalconditions,suchastemperature,sound,vibration,pressure,motionorpollutants.

Thedevelopmentofwirelesssensornetworkswasmotivatedbymilitaryapplicationssuchasbattlefieldsurveillance.Theyarenowusedinmanyindustrialandcivilianapplicationareas,includingindustrialprocessmonitoringandcontrol,machinehealthmonitoring,environmentandhabitatmonitoring,healthcareapplications,homeautomation,andtrafficcontrol.

Inadditiontooneormoresensors,eachnodeinasensornetworkistypicallyequippedwitharadiotransceiverorotherwirelesscommunicationsdevice,asmallmicrocontroller,andanenergysource,usuallyabattery.

[Wikipedia]

TheapplicationsforWSNsarevaried,typicallyinvolvingsomekindofmonitoring,tracking,orcontrolling.Specificapplicationsincludehabitatmonitoring,objecttracking,nuclearreactorcontrol,firedetection,andtrafficmonitoring.Inatypicalapplication,aWSNisscatteredinaregionwhereitismeanttocollectdatathroughitssensornodes.

2.1 WirelessStandards

Severalstandardsarecurrentlyeitherratifiedorunderdevelopmentforwirelesssensornetworks.ZigBeeisaproprietarymesh-networkingspecificationintendedforusessuchas

2 WirelessSensorNetwork(WSN)


embeddedsensing,medicaldatacollection,consumerdevicesliketelevisionremotecontrols,andhomeautomation.Zigbeeispromotedbyalargeconsortiumofindustryplayers.WirelessHARTisanextensionoftheHARTProtocolandisspecificallydesignedforIndustrialapplicationslikeProcessMonitoringandControl.

[www.ni.com]

2.1.1 ZigBee(IEEE802.15.4)

ZigBeeisalow-cost,low-power,wirelessmeshnetworkingproprietarystandard.Thelowcostallowsthetechnologytobewidelydeployedinwirelesscontrolandmonitoringapplications,thelowpower-usageallowslongerlifewithsmallerbatteries,andthemeshnetworkingprovideshighreliabilityandlargerrange.



[www.ni.com]

ReadmoreaboutZigBee:

ZigBeeAlliance:http://www.zigbee.org/

Wikipedia:http://en.wikipedia.org/wiki/ZigBee

2.1.2 IEEE802.11

WirelessDAQProductsformNationalInstrumentsusetheWi-FiIEEE802.11standard.

NIWSNMeasurementSystemsusetheZigBee(IEEE802.15.4)standard.

ReadmoreaboutwirelesstechnologyandproductsfromNationalInstruments:

NIWirelessDataAcquisition:http://sine.ni.com/np/app/main/p/ap/daq/lang/en/pg/1/sn/n17:daq,n24:Wireless

NIWirelessRemoteMonitoring:http://www.ni.com/wireless/remote_monitoring.htm

NIWirelessDevices:http://www.ni.com/wireless/

NIWirelessSensorNetworks:http://www.ni.com/wsn/

2.1.3 WirelessHART

WirelessHARTisanopen-standardwirelessnetworkingtechnologydevelopedbyHARTCommunicationFoundation.



Developedasamulti-vendor,interoperablewirelessstandard,WirelessHARTwasdefinedspecificallyfortherequirementsofProcessfielddevicenetworks

ReadmoreaboutWirelessHART:

HARTCommunicationFoundation:http://www.hartcomm.org/

Wikipedia:http://en.wikipedia.org/wiki/WirelessHART

2.2 WirelessMeshNetwork(WMN)

Meshnetworkingisatypeofnetworkingwhereeachnodeinthenetworkmayactasanindependentrouter,regardlessofwhetheritisconnectedtoanothernetworkornot.Itallowsforcontinuousconnectionsandreconfigurationaroundbrokenorblockedpathsby“hopping”fromnodetonodeuntilthedestinationisreached.Ameshnetworkwhosenodesareallconnectedtoeachotherisafullyconnectednetwork.Meshnetworksdifferfromothernetworksinthatthecomponentpartscanallconnecttoeachotherviamultiplehops.

Awirelessmeshnetwork(WMN)isacommunicationsnetworkmadeupofradionodesorganizedinameshtopology.Wirelessmeshnetworksoftenconsistofmeshclients,meshroutersandgateways.Themeshclientsareoftenlaptops,cellphonesandotherwirelessdeviceswhilethemeshroutersforwardtraffictoandfromthegatewayswhichmaybutneednotconnecttotheInternet.Thecoverageareaoftheradionodesworkingasasinglenetworkissometimescalledameshcloud.Accesstothismeshcloudisdependentontheradionodesworkinginharmonywitheachothertocreatearadionetwork.Ameshnetworkisreliableandoffersredundancy.Whenonenodecannolongeroperate,therestofthenodescanstillcommunicatewitheachother,directlyorthroughoneormoreintermediatenodes.

Wirelessmesharchitectureisafirststeptowardsprovidinghigh-bandwidthnetworkoveraspecificcoveragearea.Wirelessmesharchitecture’sinfrastructureis,ineffect,arouternetworkminusthecablingbetweennodes.It'sbuiltofpeerradiodevicesthatdon'thavetobecabledtoawiredportliketraditionalWLANaccesspoints(AP)do.Mesharchitecturesustainssignalstrengthbybreakinglongdistancesintoaseriesofshorterhops

BelowweseeanexampleofaWirelessMeshTopology:



WirelessMessNetworks(WMN)iswidelyusedinWirelessSensorNetworks(WSN).

[www.ni.com]

6

3 IntroductiontoLabVIEWSources:www.Wikipedia.org,www.ni.com

LabVIEW(shortforLaboratoryVirtualInstrumentationEngineeringWorkbench)isaplatformanddevelopmentenvironmentforavisualprogramminglanguagefromNationalInstruments.Thegraphicallanguageisnamed"G".OriginallyreleasedfortheAppleMacintoshin1986,LabVIEWiscommonlyusedfordataacquisition,instrumentcontrol,andindustrialautomationonavarietyofplatformsincludingMicrosoftWindows,variousflavorsofUNIX,Linux,andMacOSX.VisitNationalInstrumentsatwww.ni.com.

Thecodefileshavetheextension“.vi”,whichisaabbreviationfor“VirtualInstrument”.LabVIEWofferslotsofadditionalAdd-OnsandToolkits.

3.1 Dataflowprogramming

TheprogramminglanguageusedinLabVIEW,alsoreferredtoasG,isadataflowprogramminglanguage.Executionisdeterminedbythestructureofagraphicalblockdiagram(theLV-sourcecode)onwhichtheprogrammerconnectsdifferentfunction-nodesbydrawingwires.Thesewirespropagatevariablesandanynodecanexecuteassoonasallitsinputdatabecomeavailable.Sincethismightbethecaseformultiplenodessimultaneously,Gisinherentlycapableofparallelexecution.Multi-processingandmulti-threadinghardwareisautomaticallyexploitedbythebuilt-inscheduler,whichmultiplexesmultipleOSthreadsoverthenodesreadyforexecution.

3.2 Graphicalprogramming

LabVIEWtiesthecreationofuserinterfaces(calledfrontpanels)intothedevelopmentcycle.LabVIEWprograms/subroutinesarecalledvirtualinstruments(VIs).EachVIhasthreecomponents:ablockdiagram,afrontpanel,andaconnectorpanel.ThelastisusedtorepresenttheVIintheblockdiagramsofother,callingVIs.Controlsandindicatorsonthefrontpanelallowanoperatortoinputdataintoorextractdatafromarunningvirtualinstrument.However,thefrontpanelcanalsoserveasaprogrammaticinterface.Thusavirtualinstrumentcaneitherberunasaprogram,withthefrontpanelservingasauserinterface,or,whendroppedasanodeontotheblockdiagram,thefrontpaneldefinestheinputsandoutputsforthegivennodethroughtheconnectorpane.ThisimplieseachVIcanbeeasilytestedbeforebeingembeddedasasubroutineintoalargerprogram.

7 IntroductiontoLabVIEW


Thegraphicalapproachalsoallowsnon-programmerstobuildprogramssimplybydragginganddroppingvirtualrepresentationsoflabequipmentwithwhichtheyarealreadyfamiliar.TheLabVIEWprogrammingenvironment,withtheincludedexamplesandthedocumentation,makesitsimpletocreatesmallapplications.Thisisabenefitononeside,butthereisalsoacertaindangerofunderestimatingtheexpertiseneededforgoodquality"G"programming.Forcomplexalgorithmsorlarge-scalecode,itisimportantthattheprogrammerpossessanextensiveknowledgeofthespecialLabVIEWsyntaxandthetopologyofitsmemorymanagement.ThemostadvancedLabVIEWdevelopmentsystemsofferthepossibilityofbuildingstand-aloneapplications.Furthermore,itispossibletocreatedistributedapplications,whichcommunicatebyaclient/serverscheme,andarethereforeeasiertoimplementduetotheinherentlyparallelnatureofG-code.

3.3 BenefitsOnebenefitofLabVIEWoverotherdevelopmentenvironmentsistheextensivesupportforaccessinginstrumentationhardware.Driversandabstractionlayersformanydifferenttypesofinstrumentsandbusesareincludedorareavailableforinclusion.Thesepresentthemselvesasgraphicalnodes.Theabstractionlayersofferstandardsoftwareinterfacestocommunicatewithhardwaredevices.Theprovideddriverinterfacessaveprogramdevelopmenttime.ThesalespitchofNationalInstrumentsis,therefore,thatevenpeoplewithlimitedcodingexperiencecanwriteprogramsanddeploytestsolutionsinareducedtimeframewhencomparedtomoreconventionalorcompetingsystems.Anewhardwaredrivertopology(DAQmxBase),whichconsistsmainlyofG-codedcomponentswithonlyafewregistercallsthroughNIMeasurementHardwareDDK(DriverDevelopmentKit)functions,providesplatformindependenthardwareaccesstonumerousdataacquisitionandinstrumentationdevices.TheDAQmxBasedriverisavailableforLabVIEWonWindows,MacOSXandLinuxplatforms.

8

4 IntroductiontoDataAcquisition(DAQ)

ThischapterexplainsthebasicconceptsofusingDAQinLabVIEW.

Topics:

• IntroductiontoDAQ-DataAcquisition• MAX–MeasurementandAutomationExplorer• NI-DAQmxDriversoftware

LabVIEWisverypowerfulwhenitcomestocreatingDAQapplications.LabVIEWincludesasetofVIsthatletyouconfigure,acquiredatafrom,andsenddatatoDAQdevices.Often,onedevicecanperformavarietyoffunctions,suchasanalog-to-digital(A/D)conversion,digital-to-analog(D/A)conversion,digitalI/O,andcounter/timeroperations.EachdevicesupportsdifferentDAQandsignalgenerationspeeds.Also,eachDAQdeviceisdesignedforspecifichardware,platformsandoperatingsystems.

NationalInstruments,theinventorofLabVIEW,alsomakeDAQdevices,sotheintegrationwiththeDAQdevicesfromNIandtheLabVIEWsoftwareisseamlessandmakesiteasytodoI/OoperationsfromtheLabVIEWenvironment.

4.1 IntroductiontoDAQ-DataAcquisitionThepurposeofdataacquisitionistomeasureanelectricalorphysicalphenomenonsuchasvoltage,current,temperature,pressure,orsound.PC-baseddataacquisitionusesacombinationofmodularhardware,applicationsoftware,andacomputertotakemeasurements.Whileeachdataacquisitionsystemisdefinedbyitsapplicationrequirements,everysystemsharesacommongoalofacquiring,analyzing,andpresentinginformation.Dataacquisitionsystemsincorporatesignals,sensors,actuators,signalconditioning,dataacquisitiondevices,andapplicationsoftware.

Sosummingup,DataAcquisitionistheprocessof:

• Acquiringsignalsfromreal-worldphenomena• Digitizingthesignals• Analyzing,presentingandsavingthedata



TheDAQsystemhasthefollowingpartsinvolved,seeFigure:

[www.ni.com]

Thepartsare:

• Physicalinput/outputsignals• DAQdevice/hardware• Driversoftware• Yoursoftwareapplication(Applicationsoftware)

ForanIntroductiontoDataAcquisition,seethiswebcast:http://zone.ni.com/wv/app/doc/p/id/wv-169

4.1.1 Physicalinput/outputsignals

Aphysicalinput/outputsignalistypicallyavoltageorcurrentsignal.

4.1.2 DAQdevice/hardware

DAQhardwareactsastheinterfacebetweenthecomputerandtheoutsideworld.Itprimarilyfunctionsasadevicethatdigitizesincominganalogsignalssothatthecomputercaninterpretthem

ADAQdevice(DataAcquisitionHardware)usuallyhasthesefunctions:

• Analoginput• Analogoutput• DigitalI/O• Counter/timers

WehavedifferentDAQdevices,suchas:



• “DesktopDAQdevices”whereyouneedtoplugaPCIDAQboardintoyourcomputer.Thesoftwareisrunningonacomputer.

• “PortableDAQdevices”forconnectiontotheUSBport,Wi-Ficonnections,etc.Thesoftwareisrunningonacomputer

• “DistributedDAQdevices”wherethesoftwareisdevelopedonyourcomputerandthenlaterdownloadedtothedistributedDAQdevice.

• Wi-FiDAQDevices

[www.ni.com]

Wireless:

[www.ni.com]

4.1.3 Driversoftware



Driversoftwareisthelayerofsoftwareforeasilycommunicatingwiththehardware.Itformsthemiddlelayerbetweentheapplicationsoftwareandthehardware.Driversoftwarealsopreventsaprogrammerfromhavingtodoregister-levelprogrammingorcomplicatedcommandsinordertoaccessthehardwarefunctions.

DriversoftwarefromNationalInstruments:

• NI-DAQmx• NI-DAQmxBase

TheDAQAssistant,includedwithNI-DAQmx,isagraphical,interactiveguideforconfiguring,testing,andacquiringmeasurementdata.Withasingleclick,youcanevengeneratecodebasedonyourconfiguration,makingiteasierandfastertodevelopcomplexoperations.BecauseDAQAssistantiscompletelymenu-driven,youwillmakefewerprogrammingerrorsanddrasticallydecreasethetimefromsettingupyourDAQsystemtotakingyourfirstmeasurement.

NI-DAQmxBaseoffersasubsetofNI-DAQmxfunctionalityonWindowsandLinux,MacOSX,WindowsMobileandWindowsCE.

4.1.4 Yoursoftwareapplication(Applicationsoftware)

Applicationsoftwareaddsanalysisandpresentationcapabilitiestothedriversoftware.Yoursoftwareapplicationnormallydoessuchtasksas:

• Real-timemonitoring• Dataanalysis• Datalogging• Controlalgorithms• Humanmachineinterface(HMI)

InordertocreateyourDAQapplicationyouneedaprogrammingdevelopmenttool,suchasLabVIEW.

4.2 MAX–MeasurementandAutomationExplorer

Measurement&AutomationExplorer(MAX)providesaccesstoyourNationalInstrumentsdevicesandsystems.

WithMAX,youcan:

• ConfigureyourNationalInstrumentshardwareandsoftware • Createandeditchannels,tasks,interfaces,scales,andvirtualinstruments



• Executesystemdiagnostics • Viewdevicesandinstrumentsconnectedtoyoursystem • UpdateyourNationalInstrumentssoftware

Inadditiontothestandardtools,MAXcanexposeitem-specifictoolsyoucanusetoconfigure,diagnose,ortestyoursystem,dependingonwhichNIproductsyouinstall.AsyounavigatethroughMAX,thecontentsoftheapplicationmenuandtoolbarchangetoreflectthesenewtools.

4.3 NI-DAQmx



TheNI-DAQmxDriversoftwareisthelayerofsoftwareforeasilycommunicatingwiththehardware.Itformsthemiddlelayerbetweentheapplicationsoftwareandthehardware.Driversoftwarealsopreventsaprogrammerfromhavingtodoregister-levelprogrammingorcomplicatedcommandsinordertoaccessthehardwarefunctions.

[www.ni.com]

TheDAQmxpaletteinLabVIEW:

4.3.1 DAQAssistant

TheDAQAssistant,includedwithNI-DAQmx,isagraphical,interactiveguideforconfiguring,testing,andacquiringmeasurementdata.Withasingleclick,youcanevengeneratecodebasedonyourconfiguration,makingiteasierandfastertodevelopcomplexoperations.BecauseDAQAssistantiscompletelymenu-driven,youwillmakefewerprogrammingerrorsanddrasticallydecreasethetimefromsettingupyourDAQsystemtotakingyourfirstmeasurement.

14

5 IntroductiontoWirelessDataAcquisition

Source:www.ni.com

Wi-FiDAQis:

• Simple–Directsensorsconnectivityandgraphicalprogramming• Secure–Highestcommerciallyavailabledataencryptionandauthentication• Wireless–802.11g

Wi-FidataacquisitionisanextensionofPC-baseddataacquisitiontomeasurementapplicationswherecablesareinconvenientoruneconomical.NIWi-Fidataacquisition(DAQ)devicescombineIEEE802.11gwirelessorEthernetcommunication;directsensorconnectivity;andtheflexibilityofNI-DAQmxdriversoftwareforremotemonitoringofelectrical,physical,mechanical,andacousticalsignals.

[www.ni.com]

NIWi-FiDAQdevicescanstreamdataoneachchannelatupto250kS/s.Inaddition,built-inNIST-approved128-bitAESencryptionandadvancednetworkauthenticationmethodsofferthehighestcommerciallyavailablenetworksecurity.

WiththeflexibilityofNILabVIEWgraphicalprogrammingandtheubiquityof802.11networkinfrastructure,NIWi-FiDAQmakesiteasytoincorporatewirelessconnectivityintoneworexistingPC-basedmeasurementorcontrolsystems.



TheDataFlowinWi-FiDAQisasfollows:

[www.ni.com]

Unlikemostwirelesssensorsorwirelesssensornetworks,wirelessdataacquisitiondevicesaremeanttostreamdatacontinuouslybacktoahostPCorlaptop.

Awirelesssensornodeistypicallyalow-power,autonomousbattery-operateddeviceintendedforlong-termdeploymentinapplicationswheremeasurementsareneededonlyeveryfewminutes,hours,orevendays.

Wi-Fidataacquisitiondevices,ontheotherhand,behaveinmuchthesamewayasaUSBdataacquisitiondevice–ahostPCcollectsdatacontinuously(inrealtime)asthedeviceacquiresit.Thedataacquisitiondevicemaybebattery-operated,butthefocusisonthemeasurementversusthebatterylife.Also,Wi-Fidataacquisitiondevicesusethenear-ubiquitouswirelessnetworkingstandard,IEEE802.11becauseofitshigherbandwidthand



broaderapplicability.Finally,becauseNIWi-FidataacquisitionusesthesameNI-DAQmxdriversoftwareasotherNIdataacquisitiondevices,youcandevelopyourapplicationsusingNILabVIEW,LabWindows™/CVI;ANSIC/C++;orMicrosoftC#,VisualBasic,orVisualBasic.NET.

MoreInformationaboutWi-FiDAQ:

WatchtheWi-FiDAQTour:http://sine.ni.com/np/app/culdesac/p/ap/daq/lang/en/pg/1/sn/n17:daq,n21:10423/docid/wv-795

Wi-FiDAQWebcast:

http://zone.ni.com/wv/app/doc/p/id/wv-794

17

6 NIWirelessDAQDevicesCommoncomponentsinWi-FiDAQareasfollows:

• DAQDevices• WirelessAccessPoints(WAP)oraWirelessRouter• NetworkSwitches

HowdoIconnecttoanNIWi-FiDAQdevice?

WhensettingupyourNIWi-FiDAQdevice,youmaychoosetoconnecttoanexistingenterprisenetworkthroughawirelessaccesspointorsetupyourownnetworkwithawirelessrouter.ForexistingITinfrastructure,NIWi-FiDAQdevicessupportWPAEnterpriseandWPA2Enterprise(IEEE802.11i).Ifyousetupyourownnetwork,youmayuseWEP,WPAPersonal(WPA-PSK),orWPA2Personal(WPA2-PSK)security.NIWi-FiDAQdevicesalsosupportadhocorpeer-to-peernetworks,whichdonotrequireanyroutersoraccesspoints.However,adhocsupportisinconsistentacrosswirelessnetworkinterfacecardsandisnotsecure.Communicationthroughawirelessaccesspointorwirelessrouteristhepreferredmodeofoperation.

HowdoIprogramNIWi-FiDAQdevices?

AllNIWi-FiandEthernetDAQdevicesusethesameNI-DAQmxmeasurementservicesanddriversoftwareasotherNationalInstrumentsPCI,PXI,andUSBDAQdevices.NI-DAQmxmeasurementservicessoftwarecontrolseveryaspectofyourdataacquisitionsystemfromconfigurationtoprogramming.WithNI-DAQmxsoftware,youcanquicklyconfigureandacquiremeasurementsusingtheDAQAssistantandautomaticallygeneratecodetogetyourapplicationstartedquickly.NI-DAQmxalsofeaturesvirtualchannelsthatautomaticallyscalerawdataintoengineeringunits.BecauseyoucanusethesamedriverAPItoprogramnewNIWi-FiDAQdevices,incorporatingwirelessconnectivityintoyourexistingapplicationsiseasy.

Wi-FiDAQDevicesfromNationalInstruments:

18 NIWirelessDAQDevices


[www.ni.com]

TUChavethefollowingwirelessDAQdevicesavailable:

• NIWLS-9234-Wireless4-ChannelAccelerometerandMicrophoneInput• NIWAP-3701-Wirelessaccesspoints(WAPs)addwirelessconnectivitytoall

Ethernet-basedNIprogrammableautomation• NIUES-3880-Aneight-portunmanagedentry-levelswitchfornetworkingbetween

NIEthernet-basedcontrollersanddevicesusingstandardEthernetprotocols• PS-5PowerSupply

6.1 NIWLS-9234

TheNIWLS-9234isafour-channelIEEE802.11wirelessorEthernetCSeriesdynamicsignalacquisitionmoduleformakinghigh-accuracyaudiofrequencymeasurementsfromintegratedelectronicpiezoelectric(IEPE)andnon-IEPEsensors.

4-Channel,51.2kS/s/ch,24-Bit,±5VIEPEInput

• IEEE802.11b/g(Wi-Fi)wirelessandEthernetcommunicationsinterfaces• 51.2kS/sper-channelmaximumsamplingrate;±5Vinput



• 24-bitresolution;102dBdynamicrange;antialiasingfilters• Software-selectableAC/DCcoupling;AC-coupled(0.5Hz)• Software-selectableIEPEsignalconditioning(0or2mA)

TheNIWLS-9234isafour-channelIEEE802.11wirelessorEthernetCSeriesdynamicsignalacquisitionmoduleformakinghigh-accuracyaudiofrequencymeasurementsfromintegratedelectronicpiezoelectric(IEPE)andnon-IEPEsensors.TheWLS-9234delivers102dBofdynamicrangeandincorporatessoftware-selectableAC/DCcouplingandIEPEsignalconditioningforaccelerometersandmicrophones.Thefourinputchannelssimultaneouslydigitizesignalsatratesupto51.2kHzperchannelwithbuilt-inantialiasingfiltersthatautomaticallyadjusttoyoursamplingrate.

TheWLS-9234iswell-suitedfornoiseandvibrationanalysisapplications.TheNISoundandVibrationMeasurementSuite,whichspecificallyaddressestheseapplications,hastwocomponents:theNISoundandVibrationAssistantandLabVIEWAnalysisVIs(functions)forpowerspectra,frequencyresponse(FRF),fractionaloctaveanalysis,sound-levelmeasurements,orderspectra,ordermaps,orderextraction,sensorcalibration,humanvibrationfilters,andtorsionalvibration.

WLS-9234has4BNCconnectors.TheBNCconnectorisusedforRFsignalconnections.TheBNCconnectorisoneofseveralradiofrequency(RF)connectorsonthemarkettoday.

6.2 NIWAP-3701



WAP–WirelessAccessPoint

TheNIWAP-3701wirelessaccesspoints(WAPs)addwirelessconnectivitytoallEthernet-basedNIprogrammableautomationcontrollers(PACs).AWAP-37x1canconnectwirelessdevicestoawirednetworkandhasanIPaddresssootherwirelessclientscanaccessthedevice.AWAP-37x1canalsoserveasaDynamicHostConfigurationProtocol(DHCP)serverandconfigureotherWAP-37x1devicesaswirelessclients.AsingleWAP-37x1typicallysupportsupto30clientdevices,withtherangedependingonthewirelessantennaeselection.Italsoservesasawirelessbridgeandallowstwodevicestotalktoeachother.

• EEE802.11g/bwirelessaccesspoint,client,andbridge• Web-basedmanagementsoftwareincluded• 64-and128-bitwiredequivalentprivacy(WEP)security• Redundantdual24VDCpowerinputs • Metalenclosure,IP30rated;ClassI,Division2hazardouslocations • DIN-railmountingsupport

6.3 NIUES-3880UES–UnmanagedEthernetSwitch

TheNIUES-3880isaneight-portunmanagedentry-levelswitchfornetworkingbetweenNIEthernet-basedcontrollersanddevicesusingstandardEthernetprotocols.TonetworkwithNIprogrammableautomationcontrollers(PACs),theUES-3880providesindustrialfeaturesincluding-40to70°Coperatingtemperature;ClassI,Division2andATEXClass1,Zone2certificationsforhazardouslocations;andredundantdual24VDCpowerinputs.



6.4 PS-5PowerSupplyPS–PowerSupply

ThePS-5isaDIN-rail-mountable24VDCpowersupplythatprovides5Aofcurrentandisratedforoperationfrom-25Cto60C.TwoPS-5suppliescanbewiredinparalleltoprovideupto10A.ThePS-5isrecommendedforindustrialinstallations.ThePS-4isaDIN-rail-mountable24VpowersupplyinFieldPointpackaging.ThePS-3andPS-2arepowersupply"bricks"withauniversalIECpowerinput.ThePS-3canalsooperateasafloatchargerfor12VDCbatteries.ThePS-1isawall-mountpowersupply.

22

7 NIWSNDevicesAwirelesssensornetwork(WSN)isawirelessnetworkconsistingofspatiallydistributedautonomousdevicesthatusesensorstomonitorphysicalorenvironmentalconditions.Theseautonomousdevices,ornodes,combinewithroutersandagatewaytocreateatypicalWSNsystem.Thedistributedmeasurementnodescommunicatewirelesslytoacentralgateway,whichprovidesaconnectiontothewiredworldwhereyoucancollect,process,analyze,andpresentyourmeasurementdata.ToextenddistanceandreliabilityinaWSN,youcanuserouterstogainanadditionalcommunicationlinkbetweenendnodesandthegateway.

TheproprietaryNIWSNprotocolisbasedonIEEE802.15.4andZigBeetechnology.TheIEEE802.15.4communicationstandarddefinesthePhysicalandMediumAccessControllayersinthenetworkingmodel,providingcommunicationinthreefrequencybandsincludingthe2.4GHzISMband.ZigBeebuildsonthe802.15.4standardwiththenetworkandapplicationlayers,offeringfeaturessuchasdevicecoordination,reliabilitythroughmeshnetworkingtopologies,andthefunctionalitytocreateuser-definedprofilesthatallowforcustomizationandflexibilitywithintheprotocol.

WhatisthedifferencebetweenNIWi-Fidataacquisition(DAQ)andNIWSNdevices?

NIWi-FiDAQdevicescombineIEEE802.11b/g(Wi-Fi)wirelessorEthernetcommunication,directsensorconnectivity,andtheflexibilityofNI-DAQmxsoftwareforabreadthofremotemeasurementandcontroloptions.Externallypowered,NIWi-FiDAQdevicescanstreamcontinuouswaveformdataoneachchannelatmorethan50kS/sandofferthehighestcommerciallyavailablenetworksecurity(WPA2Enterprise).

NIWSNdevicesdeliverlow-powermeasurementnodesthatoperateforuptothreeyearson4AAbatteriesandcanbedeployedforlong-term,remoteoperation.ThewirelessmeasurementnodescommunicatewithacentralgatewayusingaprotocolbasedonIEEE802.15.4(ZigBee)tooffermeshroutingcapabilitiesthatextendnetworkdistanceandreliability.NIWSNsystemssupportlowerdataratestopreservepower,areeasilyprogrammedusingI/Ovariables,andcurrentlyaccommodatethermocoupleand±10Vmeasurements.

23 NIWSNDevices


[www.ni.com]

ManyoftheWSNsystemstodayarebasedonZigBeeorIEEE802.15.4protocolsduetotheirlow-powerconsumption. ZigBeebuildsonthe802.15.4layerstoprovidesecurity,reliabilitythroughmeshnetworkingtopologies,andinteroperabilitywithotherdevicesandstandards.

[www.ni.com]

24 NIWSNDevices


[www.ni.com]

7.1 Devices

7.1.1 NIWSN-9791-WSNEthernetGateway

TheNIWSN-9791EthernetgatewaycoordinatescommunicationbetweendistributedmeasurementnodesandthehostcontrollerinyourNIwirelesssensornetwork(WSN).Thegatewayhasa2.4GHz,IEEE802.15.4radiobasedonZigBeetechnologytocollectmeasurementdatafromthesensornetworkanda10/100Mbits/sEthernetporttoprovideflexibleconnectivitytoaWindowsorLabVIEWReal-TimeOShostcontroller.

7.1.2 NIWSN-3212-ThermocoupleInputNode

TheNIWSN-3212measurementnodeisawirelessdevicethatprovidesfour24-bitthermocoupleinputchannelsandfourbidirectionaldigitalchannelsthatyoucanconfigureonaper-channelbasisforinput,sinkingoutput,orsourcingoutput.

25 NIWSNDevices


7.1.3 NIWSN-3202-AnalogInputNode

TheNIWSN-3202measurementnodeisawirelessdevicethatprovidesfour±10Vanaloginputchannelsandfourbidirectionaldigitalchannelsthatyoucanconfigureonaper-channelbasisforinput,sinkingoutput,orsourcingoutput.

7.2 LabVIEWDrivers

NationalInstrumentsoffertheNI-WSNsoftware.

26 NIWSNDevices


With NI-WSN software you can easily configure your network in the Measurement &Automation Explorer (MAX) utility. MAX provides an intuitive user interface to add andremovemeasurementnodesandconfigurewirelesssettings.

NI-WSNsoftwareprovidesseamlessLabVIEWintegrationsothatyoucanquicklyandeasilyextractmeasurementdatafromyourWSN.AfteraddingtheNIWSNEthernetgatewaytoaLabVIEWProject,thenodesconfiguredwiththegatewayinMAXautomaticallypopulateintheLabVIEWProject,givingyouinstantaccesstotheirI/Oandproperties.SimplydraganddropI/OvariablesfromtheLabVIEWProjecttoaLabVIEWBlockDiagramfordataextraction,analysis,andpresentation.

NationalInstrumentsalsoofferWSNdriversforWSNequipmentsfromothervendors:

http://zone.ni.com/devzone/cda/tut/p/id/5435

Hans-PetterHalvorsen,M.Sc.

E-mail:[email protected]

Blog:http://home.hit.no/~hansha/

UniversityCollegeofSoutheastNorway

www.usn.no

wireless data acquisition in labviewhome.hit.no/~hansha/documents/labview/training/wireless...

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