Specifications

Maxiva UAX
October 17, 2013
4‐5
888‐2693‐004 WARNING:Disconnectprimarypower priortoservicing.
Copyright©2013,HarrisBroadcast
4.2.3.4 CustomerIOCard
TheTCUcontainsacustomerIOcard,whichprovidesrelayisolatedoutputsandotherremotesignalbuffering /
conditioningfortheparallelremotecontrolinterfacefoundatthetopofthetransmittercabinet.Interconnection
betweenthecustomerinterfaceboardatthetopofthetransmittercabinetandthecustomerIOcardintheTC
Uis
viaapairoffifty‐conductorribboncables.
4.2.3.5 OtherTCUComponents
TheTCUalsocontainsthefollowingcomponents:
• Base‐Plane‐providesacommonbusforthevariousplug‐incards
• PowerSupplyModule–providesDCpowertoallinternalcircuits
• GraphicalUserInterface(GUI)–apanel‐mountminiaturePCfeaturinga1/4VGAtouch
screen.
4.2.4 ControllerAreaNetwork(CAN)Bus
TheControllerAreaNetworkorCANbusisaserialcommunicationslinkusedbetweentheTCUandLPUsforthe
transmissionofcontrol,status,fault,andmeteringinformation.TheCANbusisdesignedforhostileindustrial
environmentsandoperatesindifferentialmodeforhighcommonmodenoiseimmunity.Themasterandsl
aveLPUs
cansend andreceiveinformationovertheCANbus;however,itistheMCMcardintheTCUthatdetermineswhich
informationissentandwhenitissentinthisapplication.
TheMCMca
rdcontainsLEDsthatwillflickeronandoffatarandomrateindicatingthatthereisactivityontheCAN
bus.IftheLEDsareofforalwayson,thentheCANbusismostlikelynotcommunicating.TheLEDpairDS7andDS8
isforthecabinetCANbu
s(Rx&Txrespectively).TheLEDpairDS11andDS12forasystemCANbusnotusedinVAX
transmitters.
Allfa
ultreporting,status,andmeteringinformationdisplayedontheTCUissentontheCANbusfromthe
respectiveLPUstotheMCMcard.TransmittercontrolsignalsfromtheMCMaresentviatheCANbusbutarealso
sentoverparallelcontrollinesfromaTCUinterfacecardviaDB‐25ri
bboncables.
4.2.5 TransmitterRFPowerControl
ThePAmodulesandPAblockshavenointernalgainadjustment.ThetransmitterRFoutputpoweriscontrolledvia
theoutputpowerdriveleveloftheLPUmodulatorsection.
Whenpr
esentindualdrivesystems,theTCUmonitorspowerleveldatafromtheLPUanddisplaysitontheGUIbut
doesnotcontrolit.Automaticlevelcontrol(ALC)isprovidedbyindividualALCcircuitsintheLPUmodulator
section(s).Accordingly,thecurrentlyselectedLPUsetstheoutputpowerofthet
ransmitter.Thenon‐selectedLPU
sitsinreserveandhasnoeffectonthetransmitterpowerlevel.
Themajo
rcomponentsofthetransmitterRFpowercontrolcircuitareillustratedinFigure4‐4.