User's Manual

Draft FLEXSIUserManual 7
WirelessCommunication
TheFLEXSIutilizesa779to928MHzISMbandtransceiver.Thefrequencyisconfigurabletoallowfor
ISMbandoperationinNorthAmerica,Europe,andotherlocales.Transmitpower,datamodulation,
dataencoding,anddataratesarealsoconfigurabletoallowforreliablecommunicationinnoisy
environments.Itis
recommendedtoperformasitesurveytoidentifypossiblesourcesofinterference
suchthatNumerexcanmakeadjustmentsaccordingly.
EachFLEXSIhasauniquesensoridentificationnumber(SID).TheSIDrangesfrom0to255.TheSID
shallbeincludedintheover‐the‐airmessagetoidentifythe
FLEXSIfromwhichthedatatransmission
originated.EachFLEXSIisalsouniquelypairedtoasingleFLEXthroughwhichitshallexclusively report.
InopenairtheFLEXSIcanbeupto50feetfromtheFLEXandmaintainreliablesignaling.Although
greaterdistancescanbeachieved,reliability
shouldbeassessedbeforefulldeployment.
Datatransmissionthroughvariousmaterialshasbeentestedandthroughputhasbeen showntobe
reliable.However,whennodirectlineofsiteisavailableitisimportanttotestwirelesssignalreliability
.
Aninstallationassessmentkit,consistingofaFLEXwirelessprogrammerandsoftwaretools,isavailable
fromNumerex.
Whenaneventoccursthatrequiresdatatransmission,theFLEXSIsignalstheFLEXtowakeupand
relaystheappropriateinformation.Thisprocesscantakeupto40seconds.Subsequently,theFLEX,
if
nothandlingthetransmissionofanotherevent,candelaythemessageupto40minutes.In
applicationswherepromptnessisaconcern,itisrecommendedtominimizethenumberofsensorsand
optimizetheregularreportingoftheFLEXtoensuredeliveryofdataasquickaspossible.In
atypical
applicationdatacanbeexpectedtobedeliveredinlessthan1minute90%ofthetime,within20
minutes95%ofthetime,andwithin40minutes98%ofthetime.
Installation
TherecommendedinstallationmethodistouseVHBtapetosecuretheFLEXSItotheassetbeing
monitored.Ultimately,however,eachinstallationmayrequirespecialmoun tingandshouldbeproperly
assessedbythecustomer.Installationshouldbedoneinsuchamannertoprovidedirectline ofsight
fromthe
FLEXSItotheFLEXatadistancegreaterthan3feetandlessthan50feet.TheFLEXSIshould
bemounted“screwsdown”toavoidattenuatingtheinternalantenna.Aspreviouslymentioned,
installationkitsshouldbeusedtoascertainthewirelesssignalreliabilityoftheinstallationbefore
deployment.
FactoryConfiguration
Foreachcustomerimplementation,Numerexwillloadappropriatefirmware,andconductFLEXSI/FLEX
pairingoperations.Inmostcases,thecustomerwillconnecttheFLEXSIandSensorModulecables(10
pinroundconnector)atfinalinstallation.Dependingonusage,batteriesmaybefactoryinstalledby
Numerexorshallberequiredto
beinstalledonsite.WhenafieldedFLEXistobepairedwithaFLEXSI,