Sharp SD-AT1000W Specifikace stáhnout pdf (Strana 152)

Section-3 Operation

October 17, 2013

3‐84

WARNING:Disconnectprimarypower priortoservicing. 888‐2693‐004

Figure 3-78 LPU ATSC Status Screen 3

TAD

Transmittertoante

nnadelay.Thisthethroughputdelay,measuredafterthesignalleavesthe

exciternetworkdelaycircuitandtravelstotheoutputofthetransmitter.Thisdelayisimportantif

thenetworkconsistsoftransmittersfromdifferentmanufactures,wheretheoutputprocesstime

willchangefromonemanufacturertoanother.

TotalDelay

Thisisthere

sultanttotaldelaybeingmanagedbythetimingrequirementstomeettheemission

time,includingTAD.

#ofDlyInc

Numberofde

layincrementsthatthemodulatorhashadtoperformtomaintainemissiontiming.

Highorcontinualincrementingnumbershereindicateinstabilityinthenetwork'sdistributionof

thetransportstreamortiming.Ideallythisiszero.

#ofDlyDec

Numberofdelaydecrementsthatthemodulatorhashadtoperformtomaintainemissiontiming.

Highorcontinualincrementingnumbershereindicateinstabilityinthenetwork'sdistributionof

thetransportstreamortiming.Ideallythisiszero.

Table3‐75XmtrHome>ExciterHome>Status>ATSCModulator(screen1)

Field Explanation

NetworkID

ThisistheNe

tworkIDenteredatthedistributedtransmissionadapter.IntheUSA,iscustomarytouse

theassignedTSIDforthestationasthenetworkID.

LockMetho

ATSC'sA/

110standardspecifiedtwomethodstoachievetimingreferenceforSFNemission,theyare

GPSandstreamlocked.

Inthest

reamlockedmode,theexciterextractsit'stimingfromthe19.39MHzclockembeddedinthe

transportstream.

Theexc

itersectiononlysupportsGPSlockedmode.Thismodeissetbythedistributedtransmission

adapter.Ifanothermanufacturer'sadapterisbeingusedandithasbeensetupforstreamlockedmode,

theLPUwillnotlockandafaultwillbeindicated.

WatermarkSerial

taInhibited

RFWa

termarkisaslowspeedserialdatastreamthatcanbemodulatedontoeachofthe8symbol

levelsemitted.Thisenablesuseofspecializedtestequipmentinthefieldtofigureoutwhich

transmittersarebeingreceivedinanSFNenvironment.

Inad

ditiontotransmitteridentification,theRFWatermarkcanbeusedasaslow‐speedserial

communicationchannel.TheLPUdoesnotcurrentlysupportthischannel,buttheDTxAhastheability,

incompliancewiththestandard,totelladownstreammodulatortoinhibitthemodulationofthisdata

onthewat

ermarkornot.ThisisareadbackofthesettingofthatbitintheDT xP.

Table3‐74XmtrHome>ExciterHome>Status>ATSCModulator(screen2)

Field Explanation

1 2 ... 147 148 149 150 151 152 153 154 155 156 157 ... 291 292

Sharp SD-AT1000W Specifikace Strana 152

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