PicoQuant MultiHarp 150 - Appendix; Warnings

PicoQuantGmbH MultiHarpSoftwareV.3.1.0.0
8. Appendix
8.1. Warnings
WhentheMultiHarpsoftwareisrunningwithfunctionalhardwareitcontinuouslycollectsinformation
abouttheinputsignalsandthecurrentacquisitionsettings.Ifthesesettings alongwiththeinput
ratesindicatepossibleerrors,thesoftwarewillindicatethisbyshowingawarningicon.
Whilethesoftwareisrunningininteractivehistogrammingmodethewarningiconisdisplayedatthebottomof
themainwindowinthestatusbar.InthecaseofTTTRmode,itwillappeardirectlyintheTTTRmodedialog.
Theiconcanbeclickedtodisplayalistofcurrentwarningstogetherwithabriefexplanationofeachwarning.
SimilarlytheWarnings(ifany)willbestoredinthedatafilesandcanbeinspectedviatheCurveDetailsdialog,
alsoafterre-loadingsuchafilelater.
Thewarningsaretosomeextentdependentonthecurrentmeasurementmode.Notallwarningswilloccurin
allmeasurementmodes.Also,countratelimitstriggeringaspecificwarningmaybedifferentinthevarious
modes.Thefollowingtableliststhepossiblewarningsinthethreemeasurementmodesandgivessomeexpla-
nationastotheirpossiblecauseandconsequences.
Warning Histo Mode T2 Mode T3 Mode
WARNING_SYNC_RATE_ZERO
Nopulsesaredetectedatthesyncinput.Inhistogrammingand
T3modethisiscrucialandthemeasurementwillnotworkwithout
thissignal.
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WARNING_SYNC_RATE_VERY_LOW
Thedetectedpulserateatthesyncinputisbelow100Hzand
cannotbedeterminedaccurately.Otherwarningsmaynotbereli-
ableunderthiscondition.
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WARNING_SYNC_RATE_TOO_HIGH
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.
T2modeisnormallyintendedtobeusedwithoutafastsyncsig-
nalandwithoutadivider.IfyouseethiswarninginT2modeyou
mayaccidentallyhaveconnectedafastlasersync.
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WARNING_INPT_RATE_ZERO
Nocountsaredetectedatanyoftheinputchannels.Inhistogram-
mingandT3modethesearethephotoneventchannelsandthe
measurementwillyieldnothing.Youmightsporadicallyseethis
warningifyourdetectorhasaverylowdarkcountrateandis
blockede.g.byashutter.Inthatcaseyoumaywanttodisablethis
warning.
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WARNING_INPT_RATE_TOO_HIGH
Theoverallpulserateattheinputchannelsishigherthan80MHz
(USB3.0connection)orhigherthan9MHz(USB2.0connection).
ThisisclosetothethroughputlimitofthepresentUSBconnec-
tion.ThemeasurementwilllikelyleadtoaFIFOoverrun.There
aresomeraremeasurementscenarioswherethisconditionisex-
pectedandthewarningcanbedisabled.Examplesaremeasure-
mentswheretheFIFOcanabsorballdataofinterestbeforeit
overflows.
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