PicoQuant MultiHarp 150 - Data File Formats; Interactive Mode File Format; TTTR Mode File Format

PicoQuantGmbH MultiHarpSoftwareV.3.1.0.0
8.2. Data File Formats
WhileformanypurposestheASCIIexportofhistogramstofilesortotheclipboardissufficientandeasy,you
alsomaywanttoaccesstheMultiHarpdatafilesviacustomprograms.Thissectionprovidesonlyabriefover-
viewonthefileformat.Fordetailspleaserefertotheonlinehelpfileavailableviathehelpmenu.
Toovercomecertainlimitationsofvariousdifferentformatsusedinthepast,PicoQuantnowusesaunifiedfile
format.Itisdesignedtobefuturepoofinthesensethatfilescreatedbyacurrentsoftwareversionstayvalidfor
futuresoftwarerevisionsand,moreover,filescreatedbyfuturesoftwareversionswillmostlikelystillberead-
ablebyoldersoftware,althoughtheymightcontaininformation,thatsoftwarecan'teven"know"about.Thisis
achievedbyusingataggedformat.Tagsidentifythedatatofollow,andgivethetype,lengthandevenmetain-
formation.Theexactlocationofanindividualiteminthefileisthenirrelevant.Versionrobustnessisgrantedas
longasversion-breakingchangestothesemanticsofagivenfieldareimplementedbyatagwithanewidenti-
fierratherthanexpandingtherangeorinterpretationoftheoldone.Thelistoftags(identifiers)andtheirinter-
pretationrulescanbekeptinatagdictionary.Withthisasaprecondition,thesoftwareonlyhastoshowtoler-
anceonmissingnon-mandatory(i.e.optional)content.
ThenewformatdefinitionunifiesPicoQuant'sexistingfileformatswhichindividuallyevolvedovermanyyears.
TheresultingnewTTTRfileformatwiththeextension*.ptu willbeusedforallcurrentandfutureTCSPC
productssupportingTTTRmodeandenrichesthemwithpowerfulnewfeatures.Similarly,ataggedfileformat
withtheextension*.phucoversthehistogramdataformatsofourcurrentandfutureTCSPCproducts.
Tosupportunderstandingoftheformatandimplementationofcustomsoftwareaccessingthesefiles,asetof
demosisprovidedinthesubfolder \Filedemoinyourchosensoftware installationfolder.Ifyouneedto
evaluatemoreheaderitemsthanthedemosdo,pleaserefertotheMultiHarponlinehelpfileavailableviathe
helpmenu.AfileformatrelatedHTMLhelpfileisalsoprovidedinthefiledemofolder.Itcontainsalistoftag
typesandatagdictionarythatexplainstheindividualitems.Notethatthedictionarycontainsmoreitemsthan
theMultiHarpsoftwareactuallyuses.Itisrecommendedtogobyaspecificfile,haveoneofthedemosreadit
andthenlookatthelistofheaderitemsyouget.YoucanalsousethePicoQuantFileInfoshellextensionthat
willbeinstalledbytheMultiHarpsoftwaresetuptoinspectindividualheaderitemsofa*.ptuor*.phufile.
Justright-clickonthefileinWindowsexplorerandselectProperties.
Despitetheintendedversiontoleranceofthetaggedformat,forconsistencyandsafeversioncheckingtheMul-
tiHarpdatafilesstillcarryaformatversionnumber,whichisnowcalledcontent versionandcurrentlyhasthe
stringvalue“1.0”.InordertoidentifyaMultiHarpdatafileasafilecreatedbyandtobeusedbythenativeMulti-
Harpsoftwarethereisatagassured content whichbeginswiththestring“MultiHarp“.Thereisalsoapairof
tagscreatornameandcreatorversionthatidentifythecreatingsoftware.Programmersofcustomsoftwarewrit-
ingsuchfilesMUSTUSETHEIROWNCREATORNAME.
Notethatdespiteourbesteffortstowardscompatibilityandversiontolerance,fileformatsinfuturesoftwarere-
leasesaresubjecttochangewithoutnotice.
8.2.1. Interactive Mode File Format
Thestandard MultiHarp histogramdatafilescreatedbythe MultiHarp softwareininteractive histogramming
mode(*.phu)aretaggedbinaryfileswhichcontainboththesetupparametersandtheactualhistogramdata.
Thelattercanbepresentmultipletimes,i.e.multiplemeasurementscanbestoredinonefile.Relevantsettings
arestoredforeachmeasurementseparately.InordertoidentifyaMultiHarpdatafileasafilecreatedbyandto
beusedbythenativeMultiHarpsoftware,aprogramreadinginthesefilescanreadthetagassured content
whichbeginswiththestring“MultiHarp“.However,apieceofsoftwareaimingsolelyatretrievingthehistogram
datacontentcan(andshould)betolerantaboutthistagandgoforthepurehistogramdata.Thistolerancewill
ensurecompatibilityforthefuture.Indeed,thedemosinthesubfolder\Filedemoinyourchoseninstallation
directoryarefollowingthistolerantapproach.Formoreinformationonindividualfiletagsandtheircontent,
pleaseconsulttheonlinehelpfileavailableviathehelpmenu.
8.2.2. TTTR Mode File Format
MultiHarpdatafilesfromT2andT3Mode(*.ptu)createdbytheMultiHarpsoftwarearetaggedbinaryfiles
whichcontainboththesetupparametersandtheactualeventdata.Therecanbeonlyonemeasurementper
file.Thesetupdatainthefileheaderissimilartothatinstandardinteractivemodefiles.Inordertoidentifya
MultiHarpdatafileasafilecreatedbyandtobeusedbythenativeMultiHarpsoftware,aprogramreadingin
thesefilescanreadthetagassured content whichbeginswiththestring“MultiHarp“.However,apieceofsoft-
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