PicoQuant MultiHarp 150 - Page 82

PicoQuantGmbH MultiHarpSoftwareV.3.1.0.0
Warning Histo Mode T2 Mode T3 Mode
WARNING_INPT_RATE_RATIO
ThiswarningisissuedinhistogrammingandT3modewhenthe
rateatanyinputchannelishigherthan5%ofthesyncrate.This
istheclassicpile-upcriterion.Therearesomemeasurementsce-
narioswherethisconditionisexpectedandthewarningcanbe
disabled.  Examples  are antibunching  measurements  or  Rapid-
FLIMwherepile-upiseithertoleratedorcorrectedforduringdata
analysis.Onecanusuallyalsoignorethiswarningwhenthecur-
renttimebinwidthislargerthanthedeadtime.
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WARNING_DIVIDER_GREATER_ONE
InT2mode:
Thesyncdividerissetlargerthan1.Thisisprobablynotintended.
Thesyncdividerisdesignedprimarilyforhighsyncratesfrom
lasersandrequiresafixedpulserateatthesyncinput.Inthat
caseyoushoulduseT3mode.Ifthesignalatthesyncinputis
fromaphotondetector(coincidencecorrelationetc.)adivider>1
willleadtounexpectedresults.Thereareraremeasurementsce-
narioswherethisconditionisintentionalandthewarningcanbe
disabled.
InhistogrammingandT3mode:
Ifthepulserateatthesyncinputisbelow75MHzthenadivider
>1isnotneeded.Themeasurementmayyieldunnecessaryjitter
ifthesyncsourceisnotverystable.
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WARNING_DIVIDER_TOO_SMALL
Thepulserateatthesyncinput(afterthedivider)ishigherthan
75MHz.ThisisclosetotheTDClimit.Synceventswillbelost
above78MHz.Toavoidthis,increasethesyncdivider.
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WARNING_TIME_SPAN_TOO_SMALL
ThiswarningisissuedinhistogrammingandT3modewhenthe
syncperiod(1/SyncRate)islongerthanthestarttostoptimespan
thatcanbecoveredbythehistogramorbytheT3moderecords.
Youcancalculatethistimespanasfollows:
Span=Resolution*Length
Lengthis32768inT3mode.Inhistogrammingmodeitdepends
onthechosenhistogramlength(defaultis65536).
Eventsoutsidethisspanwillnotberecorded.Therearesome
measurementscenarioswherethisconditionisintentionalandthe
warningcanbedisabled.
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WARNING_OFFSET_UNNECESSARY
ThiswarningisissuedinhistogrammingandT3modewhenan
offset>0isseteventhoughthesyncperiod(1/SyncRate)canbe
coveredbythemeasurementtimespan(seecalculationabove)
withoutusing anoffset.The offset maylead toeventsgetting
discarded.There aresomemeasurementscenarioswherethis
conditionisintentionalandthewarningcanbedisabled.
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WARNING_COUNTS_DROPPED
Thiswarningisissuedwhenthefrontendofthedataprocessing
pipelinewasnotabletoprocessalleventsthatcamein.Thiswill
occurtypicallyonlyatveryhighcountratesduringintensebursts
ofevents.
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