User guide

WirelessPointtoPoint-DIGITAL&ANALOGUE-QuickStartGuide–v1.1–June2013 6
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 www.qtech.co.nz Tel:033663713
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InternalFuse
TheWP2Pmodulecircuitisprotectedbya20mmx5mm500mAfastblowfuse.Thisis
locatedontheinternalcircuitboard.Toaccessthefuse,removethetopcoverbyprizingitoff
itsretainingdimples.Onlyreplacethefusewithanidenticaltype,donotusealternatives.
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RadioAddress(RA)
AllWP2Psystemshaveaunique“radioaddress”whichisprogrammedintoWP2Pmodules
duringmanufacture.
Theradiocodeisrepresentedandspecifiedinthefollowingformat“192.168.0.0”,itisa
securitymeasuretopreventunauthorisedusers.
Note–AllWP2Pmodulesinagivensystemmusthavethesamefirstthree
numbersintheir“radioaddress”andthe4
th
numbermustbeasequentialpairstarting
fromtheevennumbere.g0.1.1.40&0.1.1.41.ThecodeisontherearofWP2P
modules.TheradiocodemustbestatedforpurchasingforWP2Pmodulereplacement.
UsingMultipleWP2PSystemsinthesamearea
Therearetenindividualfrequencybandsreferredtoas“Channelnumbers”allowinguptoten
WP2Psystemstobeusedinthesamelocation.The“Channelnumber”isidentifiedbythe“#”
onthepackaginglabel;thisexampleis“Channel#1”.
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Warning–Donotusethesamechannelforadjacentsystems.Forexample,ifyou
currentlyuse“#1”ensuretheadjacentsystemis“#3”etc.
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Operationalnotes–Howdothemodulescommunicate?
TheWP2Pmodulesusean“eventdriven”approachtocommunications.Whenthestateof
anyinputchangestheWP2Pmodulewillimmediatelycommunicatethatchangetotheother
WP2Pmodule.Thisapproachresultsinveryfastresponsetimes.
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IfthecommunicationslinkbetweenapairofWP2Pmodulesgoesdown(forexampleifoneof
themlosespower),thentherelayoutputstateoftheonmoduleismaintainedatthevalueit
waspriortothelinkgoingdown.
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Inadditiontotheswitchinputstatechangemessageandthekeep-alivemessage,theWP2P
–DIGITAL&ANALOGUEmoduleswillsendamessagewhentheiranalogueinputvaluehas
changedbygreaterthan2.5%FSDsincethelasttimeitsentanymessage.(2.5%FSDis
0.5mAforacurrentloopconfiguredmodule).Thismeansthatforaveryfastchanging
analogueinputvalue,thecorrespondingoutputwillbealwayswithin2.5%oftheinputvalue.
Then,whenthemodulesendsakeep-alivemessageoraswitchchangemessage,the
currentanalogueinputvalueisalsosent,sotheoutputvaluewillbeequaltotheinputvalue.
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WhentheWP2Pmodulesdetectachangeoftheirinputstate,theywillimmediatelytransmita
messagetotheothermodule.ThereisaverysmallchancethatanotherWP2Pmoduleon
thatchannelalsowantedtosendamessageatexactlythesametime.Thiswillresultina
“collision”,buttheWP2Pmodulescandetectthatacollisionhasoccurred,andwillthenusea
collisionavoidanceschemetoretransmittheirmessages.
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Specificationsmaybesubjecttochange