System User Guide / Owners Manual

18
Setup – Peripherals
1.Onthe“Synchronisation”tab:selectdevice“SyncHD”andport“any”(theLTC
inputwillbeautomaticallyselected)
2.Onthe“MachineControl”tab:tick“9pinsserial”(SonyP2).Untick“useserial
timecodeforpositionalreference”.LeavingthisoptiontickedcausestheSync
HDtotrysyncingtovideosyncinsteadofwordsync.Anadditionaldisadvan-
tageofSonyP2isthatitdoesnotsporta“continuousresync”likeLTC,signal-
ingtimecodeonlytogetherwithtransportcommands.
Setup – Session setup
3.SetSyncSourceto“WordClock”(thepreviousstepwillhaveautomatically
selectedvideosyncinstead,hencetheneedforexecutingthestepsinorder).
TheLoopSyncindicatorswilllightup.
Controllingtheexternalmachinecanbedoneintwoways:
a.ThetransportbuttonsonProToolscontrolthemachineviatheSonyP2interface.
ThemachinegeneratesLTC.ProToolsisslavedthroughtheSyncI/O’sLTCinput
oranyotherLTCtoMTCconverterconnectedtoyourcomputer.Lockisachieved
withinonesecond.Thisisthepreferredmethod.
b.ProToolsiscontrolleddirectlybyitstransportbuttons.Theexternalmachine
locatesandgetsintoplaythroughSonyP2locatorcommands.Theuserselectsa
cuepointandhitsplay.Theexternalmachinewillrewindtothistimecodeminusa
pre-rollandstartsrolling.ProToolswaitsuntilitseesthecorrecttimecodecoming
back(ProToolsslavestotheLTCofthemachine).Apotentialproblemoccurswhen
theexternalmachinefailstoachievesyncduringthepre-rollperiod.Whenevery-
thingisslavedtowordsyncthereislittlechanceofsuchathinghappeningandone
secondofpre-rollshouldsuffice.Whileplaying,ProToolswillrunintriggersync
mode.Thatis,onceit’sstartedplayingitwillignorepositionalinformation,verify-
ingonlythattimecodeisstillrunning.Thismethodmayforinstancebeselected
whenusingharddiskvideoplayers.
6. Jitter and PLL’s explained
Jitterisaninstabilityinthetimingofaclocksignal.Ideallytherisingorfalling
edgesofaclocksignalareallseparatedbyexactlythesameamountoftime.In
reality,thetimingismoreuncertain.Thegraphbelowshowsthetime-domainview
oftheproblem.