Specifications

Section-4 Theory
November 11, 2013
4‐4
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4.4.3 TVSyncDistribution
TheTVsyncsignalisroutedfromtheexciterstoJ5andJ6onthedown converterboard,whichislocatedinsidethe
mainandPAcabinetsontheceiling.Inthedownconverterboard,thesyncfromtheonairexciterisroutedtosync
outputconnectorsJ7,J8,and
J9.FromJ7,thesyncisroutedtotheIPAandPAbackplanestoprovidepeakofsync
detectionfortheIPAandPAmodules.ThesyncoutputsfromJ8andJ9areroutedfromthemaincabinettothe
additionalPAcabinetsinamulticabinetsystem.
4.4.4 TCUControl
TheheartoftheMaxivacontrolsystemistheTCU(transmittercontrolunit).EachcabinetcontainsaTCU.Themain
cabinet(cabinet1inmulticabinetsystems)containsanenhancedTCU(withaGUIscreen),whileadditionalPA
cabinetscontainabasicTCU(withoutGUIscreen).ThebasicTCUwillnot
beequippedwithallofthesame
componentsastheenhancedunit.Thecabinet1TCUassumes theroleofmastercontrollerinmulticabinetsystems.
TCUsinaddedPAcabinetsareslaves.
4.4.4.1 MCMCard
EachTCUcontainsanMCM(mastercontrollermodule)card.TheMCMisamicroprocessorbasedcontrollerusedfor
allcriticaltransmittercontrolfunctions.TheMCMcardsineachcabinetTCU(inmulticabinetsystems)aretied
togetherviathesystembus.Thesystembusallowsinterchangeofcontrolandstatus
informationbetweenthe main
cabinetTCUandadditionalPAcabinets.TheMCMisresponsibleformaintaininglifesupportoperationwhenthe
PCMcardandGUIarenotoperational.Thesystembusconnector(J6)connectionsareprovidedin
Table4‐10on
page4‐16.
Thecabinetbusconnector(J5)haslimiteduseinthistransmitter.Pin7istheonlysignalusedinthecabinetbus.It
sendsthePA_voltage_selectsignaltotheIPAandPAbackplanes,fromwhichitissenttotheIPAandPAmodules,
whereitcontrolstheDCoutputvoltage
fromtheeightACtoDCconvertersineachmodule.

Figure 4-3 MCM Card Block Diagram