User manual

CLKTCDSeriesUserManual–Rev.2.0.1Page16
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TheCLKTCDanalogclockprovidesflexibleconfigurationoptionssupportingmostDSTstandards.
Pre2007Standard–U.S.A.andCanada
TraditionalUS/Canadadaylight/summertimeisconfiguredasone(1)hourpositivebias.For
theU.S.(through2006)andCanada,daylightsavingstimebeginsonthefirstSundayofApril
at2:00AM(LocalTime)andendsonthelastSundayofOctoberat2:00AM(LocalTime).
Post2006Standard–U.S.A.andCa
nada
OnAugust8,2005,theEnergyPolicyActof2005wassigned.ThisActchangedthetime
changedatesforDaylightSavingTimeintheU.S,effectivein2007.DSTno
wbeginsonthe
secondSundayofMarchat2:00AM(LocalTime)andendthefirstSundayofNovemberat
2:00AM(LocalTime).
EUStandard–EuropeanUnion
IntheEuropeanUnion,daylightchangetimesaredefinedrelativetotheUTCtimeofday
insteadoflocaltimeofday(likeintheU.S.).FortheEuropeanUnion,summertimeperiod
beginsat1:00AMUTConthelastSundayofMarchandendsat1:00AMUTConthelast
SundayofOctober.Europeancustomers,pleasecarefullyconsultthesectionentitled“Device
Settings”fordetailsonsettingdaylighttime.
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Toensureproperhands‐freeyear‐aroundoperation,DSTadjustmentsmustbeconfigured
usingthedaylighttimeoptionandnotwiththetimezoneoffsetoption.
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FreewheelingAccuracy
TheCLKTCDhasbuilt‐inprovisionstoallowtheclocktofreewheelandmaintainaccuracyfor
extendedperiodsintheabsenceoftimecode.Thesefeaturesalsoallowtheunittobesetmanually
andoperatewithouttimecode.
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TCXOandRTCcircuit
TheCLKTCDcontainsaprecisionTCXOandRTCcircuitallowingtheclocktomaintainan
accuracyof+/‐1minuteperyeartothelastknowntimecodeinput(+/‐165mSperday)
whentimecodeisnotpresetorcannotbedecoded(i.e.freewheelingmode).
Maintenance‐freeRech
argeableBattery
TheRTCandTCXOaremaintainedcontinuouslyfromarechargeablebatterycircuitduring
periodsofpoweroutage.Minimumholdoverperiodistwoweeksoncethebatteryis
charged.Thebatterywillautomaticallychargewhentheunitisnextpoweredandrequires
nomaintenance.
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Non‐VolatileConfiguration
Theclockconfigurationsaremaintainedinnon‐volatilememoryallowingthecurrentsettingstobe
retainedduringpoweroutages.