1

Test and Troubleshooting Guide for Optical Fiber Cabling and DataCommunications.

N E T W O R K S U P E R V I S I O N

Test and Troubleshooting Guide for Optical Fiber Cabling and DataCommunications.

N E T W O R K S U P E R V I S I O N

32

Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2. Fiber Verification Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3. How to Certify Optical Fiber Cabling with OLTS and LSPM . . . . . . . . . . . . . . . . . . . . 6

4. How to Certify Optical Fiber Cabling with an OTDR . . . . . . . . . . . . . . . . . . . . . . . . . 12 • OTDRbuiltspecificallyfortheenterprise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 • OTDRcertificationset-up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 • Summaryofextendedcertification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 • Cablecertificationteststrategy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5. Finding and Analyzing Fiber Cabling Faults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 • Commonfaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 • Simplefaultfinding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 • Advancedtroubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 • Troubleshootingbasics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

6. End-face Inspection and Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 • Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 • Cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

7. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

8. Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

9. Appendix • FlukeNetworksFiberTestandTroubleshootingInstruments . . . . . . . . . . 27

54

1. IntroductionAs fiber links support higher-speed network bandwidths with increasingly stringent requirements, it’s becoming more important to ensure your backbone links meet tightening loss standards. The need for higher data transmission capacity continues to increase as net-work applications grow and expand. These higher transmission speeds demand cabling that delivers increased bandwidth support. This test and troubleshooting guide outlines cabling performance requirements, field testing, certification and troubleshooting techniques and instruments to ensure the installed optical fiber cabling supports high data rate applications such as 1 and 10 Gigabit per second (Gbps) Ethernet, Fibre Channel and 40 and 100 Gbps Ethernet applications.

A local area network (LAN) or an enterprise (“premises”) network typically connects users up to a distance of 5 km. It encompasses intra-building connectivity, as well as inter-building or campus cabling. Optical fiber cabling is primarily used for longer distance, higher band-width connectivity, while twisted-pair copper cabling typically provides the connection to the end-user or edge devices. This copper cabling can support network connectivity to a distance of 100 meters (328 feet). Optical fiber cabling is the preferred medium for distances beyond 100 meters – such as riser cables in a building.

This guide reviews best practices for test and troubleshooting methods, as well as rec-ommended test tools to ensure installed optical fiber cabling provides the transmission capability to reliably support LAN or enterprise network applications. “Certification,” or the process of testing the transmission performance of an installed cabling system to a specified standard, ensures a quality installation. It also provides official documentation and proof that the requirements set by various standards committees are fully satisfied.

Optical fiber is a reliable and cost-effective transmission medium. But, because precise align-ment of very small fibers is crucial, problems ranging from end-face contamination to excess modal dispersion can cause failures. Regardless, narrowing down the source(s) of failure is often a time-consuming and resource-intensive task.

That’s why Fluke Networks created this enterprise-focused fiber troubleshooting guide – to help you better assess the quality of a cable installation. And, to help you troubleshoot more effectively so you can fix a problem faster, rather than spending time trying to identify it. Note: this guide doesn’t address issues especially germane to the long-haul telecommunica-tions application of the fiber optic technology.

2. Fiber Verification TestingFiberverificationtesting(includingend-faceinspectionandcleaning)shouldbeapartoftechnician’sstandardoperatingprocedures.Throughoutthecableinstallationprocessandbeforecertification,youshouldmeasurethelossofcablingsegmentstoensurethequalityoftheinstallationworkmanship.ThistestisnormallydonewithaLightSourceandPowerMeter(LSPM)testset.Fiberverificationtesttoolsaretypicallylessexpensivetools;they’realsoeffectiveintroubleshootinglinks.Aquickinspectionoftheend-to-endlinklossmayindicatewhetherornottheopticalfibercableissuspectorwhetherothernetworkfunctionsarethecauseofthemalfunction.

AnLSPMdeterminesthetotallightlossalongafiberlinkbyusingaknownlightsourceatoneendandapowermeterattheother.But,beforethetestcanbedone,measureandrecordareferencepowerlevelfromthesourcetosetabaselineforthepowerlosscalcula-tion.Afterthisreferenceisestablished,plugthemeterandsourceintotheoppositesidesofthefiberlinktobetested.Thesourceemitsacontinuouswaveattheselectedwave-length.Onthedistantend,thepowermetermeasuresthelevelofopticalpoweritreceivesandcomparesittothereferencepowerleveltocalculatethetotalamountoflightloss(Figure 1).Ifthistotallossiswithinthespecifiedparametersforthelink-under-test,thetestpasses.

Alossbudgetshouldbewellestablishedandusedasabenchmarkduringcabling installation.Ifthisverificationtestingisperformedduringinstallation,youcanexpectthatyieldwillincreaseandcertificationtestingwillgomoresmoothly.

Historically,LSPMtestsetsrequiremanualcalculationsandsubjectiveinterpretationby experiencedtechnicians.However,newerinstrumentsautomaticallycomparepower measurementstosetreferences,eliminatingthetime-consuminglosscalculations.

UsinganLSPMsettoverifyend-to-endlossisconvenient.But,itdoesn’tindicatewheretroubleareasare.Failurescanbedifficulttolocateandanalyze.Evenwhenthelossiswithinaspecifiedthreshold,theLSPMsetdoesn’tprovideanywarningorindicationofwhereadefectorproblemmaybe.Inotherwords,althoughanentirelinkmaypass,it’spossibleindividualsplicesorconnectionswithinitmayfailindustryspecifications.Thiscreatesapotentialprobleminthefutureduringadds,movesorchangeswheremultipledirtyconnectorsmightbegroupedtogetherandresultinafailure.AnOpticalTime DomainReflectometer(OTDR)canpinpointlocations(connections)displayingahighlossorreflectance.

Fiber under test

*Mandrel used only for850/1300 nm testing

Figure 1–ConductinganLSPMtest

76

3. How to Certify Optical Fiber Cabling with OLTS and LSPM

IndustrystandardsrequireusinganLSPMorOpticalLossTestSet(OLTS)tocertifythelossofeachlinkmeetsperformancestandards.Thisisreferredtoas“basic”orTier1Certifica-tionandconsideredthemostimportanttestinginregardstonewcablinginstallations.

Tier1Certificationisadouble-endedtestwhichproducesanabsolutelossmeasurement.Thatmeasurementisthencomparedwithinstallationcablingstandardsand/orchan-nelapplicationstandards.FlukeNetworks’DTXCableAnalyzer™cansupportmultimodeorsinglemodefibertestmodulesthatautomatemostofthetestandmake“basic”orTier1certificationeasy.

AnOTDRcanalsoprovidelossresultsforthetotallink.But,thismeasurementisbasedonthereflectedlightenergy.ThestandardsdemandthebasiccertificationbeexecutedwithanOLTSorLSPM.Thelinklossresultsprovidedbyusingalightsourceononeendandalightmeterattheoppositeendaremoreaccurate.

Followthesestepstoperformabasiclosslengthcertificationtest:• EstablishPass/Failtestlimits

• Chooseatestmethodandsetareference

• Runthetestandsaveresults

• ExporttoLinkWaretomanageandarchivethetestresults.LinkWareisFlukeNetworks’freecabletestmanagementsoftwaretocreateprintedorelectronicreports

1. Establish Pass/Fail limitsinaccordancewithyourcertificationgoals.Inthisexample,wewillestablishlimitsforthetotalallowablelossbasedonanapplicationstandardusingtheFlukeNetworks’DTXSeriestesterequippedwiththeDTX-MFM2fiberlosstestmodules(formultimode).Ifyouneedtocertifysinglemodefiber,usethe DTX-SFM2modules.

a. Oncethetesteristurnedon,turntherotarydialto“Setup”andselect “InstrumentSettings”toinputtheoperatorname,jobname,etc.

b. SelectFiberLossfromtheSetupscreenasshowninfigure 2.Underthissetupscreen,choosefromamenuofstandardstoselectthecorrectlimits.SelecttheTestLimitoptionasshowninfigure 3.Notethattheselectedfibertypelimitsthetestlimitchoices.Popularfibertypesarealsoincludedintheinstrumentmenu.

Asfigure 3shows,thesamesetupscreenallowsyoutoselectthe“RemoteEndSetup”.WhenusingtheDTXSmartRemoteequippedwiththefibertestmodule,select“SmartRemote”aswehavedoneinthisexample.Inthismode,thetesterautomati-callymeasuresthelengthofthelink-under-test.

Lastly,thisscreenallowsyoutotellthetesterwhetheryouneedtotestthelink-under-testinbothdirections.Ifthisisthecase,remembernevertodisconnectthetestreferencecord(TRC)fromthetestmodules.AlwaysswaptheTRCatthecon-nectionwiththelink-under-test.

2. Choose a reference method and set it – Asdescribedearlier,settingareferenceisa criticaltoobtainingaccuratetestresults.Thepowermeterandlightsourceareconnectedtogetherandthepowerlevelismeasuredbythelightmetertoestablishthe“reference”forlosscalculations.

Stepsforsettingareference:

StepA. Turntherotaryswitchto “SpecialFunctions”andchoose “SetReference”(Figure 4).

StepB. Press“Enter”andconnecttheTRCs betweenmainandremoteasshownon thescreenandpress“Test”tomakethereferencemeasurement.

WiththeDTXSeriesinSmartRemotesetup,youcantestthetwofibersthatmakeupthetransmissionlinkinonetest.Eachfibertestmoduleisequippedwithalightsourceandlightmeter.Inthesetup,you’llusetwoduplexTRCs.Onefiberwillconnecttheoutput(lightsource)atthemainunittotheinput(lightmeter)attheremoteunit.Thesecondconnectstheoutputattheremoteunittotheinputatthemainunit.

Figure 2

Figure 4

Figure 3

98

Specialnote:TheDTXTRCsusethefollowingconventiontoquicklymakeconnectionsandverifythepolarityofthelink-under-test:thelightentersthecordattheredbootandleavestheTRCattheblackboot.So,oneendofaTRChasaredbootandattheotherendofthatsamecordisablackboot.Thelighttravelsfromredtoblack.TheDTXscreendisplayshowsthebootcolor(Figure 5).

Figure 6showsthisreferencesetup.Thisfigureusesadifferentcolorforthetwoduplexcords.Thesecolorsdon’trelatetotheactualcords,butwerechosentomakethefiguremoreclear.Theyellowcordconnectstheoutput(lightsource)ofthemainunit’sfibermoduletotheinput(lightmeter)oftheremoteunit.Oneoftheyellowcordsisn’tconnectedinthereferencesetting.Oneofthedarkercoloredcordsmakestheconnectionintheoppositedirection.Figure 6alsoshowsthelocationofthemandrelneartheendwiththeredbootthatistobeconnectedtothelightsource.Theduplexcordshaveonelongerlegwiththeredboot.Afterthisleghasbeenwrappedaroundthemandrel,thelengthsofbothcordsintheduplexarrangementareequal.

TheDTXfibermodules’outputportsarealwaysSCconnectors.Theremovableadaptersfortheinputportsarechosentomatchtheendconnectorsofthelink-under-test.Theexampleinfigure 6showsthelink-under-testequippedwithLCconnectors.

Figure 6 – Setting the reference with duplex TRCs for a link-under-test ending with LC connectors. The ring near the red boot indicates the location of the mandrel (for multimode fiber).

StepC. Afterthetestermeasuresthereference powerlevel,itdisplaysthesevaluesasshowninfigure 7.Ifyourreference valuesareacceptable,presstheF2 softkeytostorethesevaluesandto proceedwithlinkcertification.

Acceptable Reference Values*

Model62.5 μm

Multimode50 μm

Multimode9 μm

Singlemode

MFM,MFM2 -20dBm -24.5dBm N/A

SFM,SFM2,GFM,GFM2

-8dBm -8dBm -208m

*nominal level

StepD.NowdisconnectyourTRCsat the Input ports onlyandcreatetheconnectionshownonthescreen(Figure 8). Disconnecttheblackbootsfromtheinputportsandconnecttheunusedendswiththeblackbootsintheduplexcordsettotheadapterontheinputportoftheunittowhichtheduplexmatehasbeencon-nected.Youhaveseparatedthemainandremoteunitssoyoucanconnectaunitateachendoftheopticalfiberlinktobetested.

Guidelines for setting a reference• Usehigh-qualityTRCs• CleanTRCendsbeforeyousetthereference• Letthetesterwarmuptoasteady-stateinternaltemperature

(about10minuteswithambienttempandstoragetempdifferenceof<20°F)• Usepreferredone-jumperreferencemethod• PlugtheSCadapterwithredbootplugsintothetransmitter(OUTconnection)• Donotunplugredboot(onsource)aftersettingthereference• Afterthereferenceisset,doNOTdisconnectTRCfromlightsource• Foramultimodeopticallink,usethepropermandrel• Referencemustberesetaftertheunitsarepowereddown• Maintainpreciselaunchconditionsofthereference

Figure 5

Figure 8

Figure 7

Main to Remote

Main Unit

Out In Out In

Remote UnitLC Adapters

Remote to Main

LC

LC

LC

LC

LC

SC SC

1110

3. Run an autotest Select“Autotest”.TheteststandardyouselectforanAutotestdeterminesthetest

parametersandthePass/Failcriteriaforeachtest. Polarity –AsuccessfulAutotestusingtheDTXFiberModules,ensurespolarity.

•ConnecttheblackbootoftheTRCtothefiberinthelink-under-testtransmittingthelight.Thisendofthelinkneedstobeconnectedtothetransmitterofthenetworkdevice.(LightleavestheTRCattheblackboot.Theredbootendofthatcordiscon-nectedtotheoutputonthetester).

•ConnecttheredbootoftheTRCtothefiberinthelink-under-testreceivingthelightfromtheotherendofthelink.

•Whentheconnectionstothelink-under-testareestablished,theinstrumentwillchirpa“happytone”toindicateconnectivityhasbeenestablishedandthepolarityofthelinkisgood.

Length–Thetestermeasuresthelength,aswellasthelinkloss.Whenyouselectan applicationstandardduringthesetup,itincludesthemaximumlengthforthe applicationdependingonthebandwidthratingoffiberusedinthelink-under-test.

Makesuretheconnectoronyourfibertestadaptermatchesthefiberpatchcordorthepatchpanel.ConnectTRCstothelinkorchanneltobetested:repeattheprocessdisplayedinfigure 8.

Specialmodecontrollersareavailabletouseinplaceoftraditionaltestreferencecordsfortestspecificationsthatrequireencircledfluxlaunchconditions. (seeFigure 9)

Bidirectional testing–Ifyouwanttotesteachfiberinbothdirections,don’tforgettoselectthatoptioninthesetupscreen(seeFigure 3).Whenthetesterpromptsyoutomaketheconnectiontotestintheseconddirection,remembertoswitchthe TRCatthelinkend.DONOTremovetheTRCsfromthetesterconnections.

Test Results–Besuretosaveresultsbeforetestingintheotherdirectionormovingontothenextfiber.Figure 10showsthedetailedmeasurementsofafiber.Notethateachfiberistestedatbothwavelengthsdemandedbytheinstallationstandard.

Applicationsstandards,ontheotherhand,onlyspecifyperformanceforthewavelengthofthe applications.Forexample,the10GBASE-Sstandardspecifiesthelinkrequirementsat850nm.Thename“input”fiberor“ouput”fiberinthetestresultscreenreferstotheportinthemainunittowhichthefiberisconnected.Theresultshownin figure 10pertainstothefiberthatisconnectedtotheinputportatthemaintesterunit.Thescreentitle“Loss(RgM)”,whichmeansLossfromthe RemoteunittotheMainunit,alsoindicatesthefiberforresultdisplayed.

Onceyou’vetestedallthelinksandsavedeachrecord,youcandownloadresultstoaPC,inspectandmanagethemwithLinkWareResultsManagementsoftware.YoucanalsoprintaSummaryTestReportforthejob,aswellasaprofessionalreportforeachlinktested.LinkWareletsyoucreatereportsasPDFfiles.

Testing MPO cabling componentsTotestopticallinksandchannelsconstructedwithmultifiberMPOcablingcomponents,itisrecommendedtouseaspecialtesterforincreasedefficiency.WithFlukeNetworks’MultiFiberProPowerMeterandLightSource,youcanfollowsimilarproceduresandtestall12fibersatonce. TheMultiFiberProbringssimplicitytomulti-fibercabletestinginanyenvironment. ItisatrueMPOconnectorfibertester,abletosimultaneouslytestall12fibersinanMPOtrunkcable.

To test a multi-fiber cable, start with setting the reference –• Asusual,cleantheend-faceconnectorswithanMPOfibercleaner,thensimplyconnect

oneofthetestcordstothepowermeterandlightsource.Makesurethelightsourceisin“ScanAll”modewith“AutoWavelength”on.

• Pressthe“Menu”buttononthepowermetertoenterthe“SetRef”mode.Oncethemeasurementisready,pressF1tosavethereference.

• Afteryou’vesetthereferencewiththesuppliedMPOtestcords,selectalosslimit.Press“Menu”for3seconds,andthenusethearrowkeystomovetoLossLimit. Press“Menu”againandusetheF1orF2keytosetyourdesignatedlosslimitvalue.

• NowpressMenuoncetosave.ThenpressandholdtheMenukeytogobacktothe mainscreen

Figure 10 – “Loss” test results for the fiber connected to the input port on the main tester unit. The result includes the loss for both multimode wavelengths (installation test standard).

Figure 9 – Encircled Flux Mode Controller

1312

• NowsimplyconnectyourtestcordstotheMPOtrunkcableand,inlessthan6seconds,you’llhavethelossandpolaritymeasurementsforall12fibers.Thesimpleuserinter-faceallowsyoutoeasilydetermineifthecablepassesthelosscriteriayou’veset.Anyfiberthathasexcessivelosswillbeeasytospotinthesimplebargraph.

Documenting the ResultsTosimplifytestresultsmanagement,MultiFiberProtestresultscanbeeasily uploadedtothepopularLinkWare7cabletestmanagementsoftware.

ConnectthemetertoyourlaptopwithLinkWare7running.InLinkWare,usethe“Import”functiontoextractallthetestsresultsfromtheMultiFiberPropowermeterandprofessionaltestreportscanbecreated.

ForthemostrecentversionofLinkWaresoftware,pleasevisit: www.flukenetworks.com\linkware

4. How to Certify Optical Fiber Cabling with an OTDR

TherearedifferenttypesofOTDRsavailable.TIA568C.0andISO14763-3recommendOTDRtestingasacomplementarytesttoensurethequalityoffiberinstallationsmeetscompo-nentspecifications.Thestandardsdon’tdesignatePass/Faillimitsforthistest.Youshouldconsidergenericcablingrequirementsforcomponentsanddesigncriteriaforthespecificjob.YoucanuseanOTDRasasingleendedtester,bidirectionally(ifdesired)andoption-allywithareceivefiberforcertificationtesting.

What you need to know about OTDRs.OTDRsusedtobehard-to-operatelaboratoryequipment–impracticalforfielduse.Theywerebig,heavyandcomplicatedforinexpe-riencedtechnicianstosetupandoperate.Testresultsweredifficulttounderstand.Thiscreatedfearandconfusion.Today,however,manynewOTDRsaresmall,lightandeasytouse.Anordinarytechniciancantroubleshootlikeanexpert–butabasicunderstandingofhowanOTDRworksisstillhelpful.

• Basic operation–AnOTDRinfersloss,reflectanceandlocationofevents.Itsendspulsesoflightintoafiberandusesasensitivephotodetectortoseethereflectionsandplotthemgraphicallyovertime.Inordertoaccuratelytest,theopticalcharacteris-ticsofthefibermustbedeterminedandsetpriortotesting.

• OTDR trace–TheOTDRplotsthereflectanceandlossovertimeinagraphical“trace”ofthefiber.Experiencedtechnicianscan“readatrace”andexplainit.Forexample,infigure 11,anexperiencedeyecanspotthatonesideofacrossconnectshows excessiveloss.

• Event analysis software–ThelatestOTDRsrunsophisticatedsoftwarethatautomatestraceanalysisandsetupoftestparameters.FlukeNetworks’OTDRscanautomaticallychoosesetupparameters,notonlytellingyouwhereevents(instancesofreflectanceandloss)areonthetrace,butalsoindicatingwhattheeventsareandqualifyingeachofthem.

• Dead zone–Thelengthafteraconnector,splice,breakormacro-bendalongthefibercablingwheretheOTDRcanmakeanattenuationmeasurementordifferentiatebetweencloselyspacedeventssuchasconnectors.EventdeadzoneistheminimumdistancebetweentwoconsecutivereflectiveeventsthattheOTDRcanmakeameasurement.At-tenuationdeadzoneistheminimumdistanceafterareflectiveeventthattheOTDRcanmakealossmeasurement.

• Dynamic range–Determinesthelengthoffiberthatcanbetested.Thehigherthedynamicrange,thelongerthefiber-under-testcanbe.However,asthedynamicrangeincreases,thewidertheOTDRpulsebecomesandasaresult,thedeadzoneincreases.

• Ghosts–Notasscaryastheymightseem,ghostingiscausedbyanechoduetohighlyreflectiveeventsinthelinkundertest.FlukeNetworks’OTDRsidentifyghostsonthetraceandtellyouwherethesourceoftheghostissoyoucaneliminateit.

• Gainers –AnothermisunderstoodphenomenononanOTDRtraceisagainer. Simplyput,againerisanapparentnegativelossataneventwherethereisachange intheopticalperformance.Thisisusuallyduetoamismatchbetweentheindexof refractionoftwosplicedfibersorconnectionofa50µmmultimodefiberintoa 62.5µmfiber.Thistypeofeventwilloftenexhibitexcessivelossintheotherdirection.

OTDR built specifically for the enterprise. TheOptiFiberProOTDRisanOpticalTimeDomainReflectometerthatlocates,identifiesandmeasuresreflectiveandlosseventsinmultimodeandsinglemodefibers.Typicalmaximumtestrangesarelessthan35kmat850nmand/or1300nmwavelengthsformultimodefiberandwellbelowtheinstrument’srangeof130kmforsinglemodefiberwhichshouldbetypi-callytestedat1310and/or1550nmforsinglemodefiber.

130 m 7 m 80 m

Figure 11 – Sample OTDR trace with high loss connector at 137m

1514

Trace View–Whentestingafiberlinkorchannel,changethewavelengtheasilytoviewthetrace.Zoomintoseedetaillossinfoandeventcharacteristics.• Jumptonext/previousevent

• Pinchtozoomout

• Reversepinchtozoomin

• Dragtomovethetrace

• Slidetoadjustxoryzoom

• Doubletaptozoomto100%

Asmentionedatthebeginningofthissection,therearedifferenttypesofOTDRsavail-able.TheOptiFiberProOTDR,withitsadvancedfeaturesetandcapabilities,wouldbeanexcellentchoiceforcertifyingenterprisefibercabling.But,sincemanycontractorsandnetworkownersusetheDTXCompactOTDRfor“closettocloset”certification,wewilldemonstratehowtoperformthistypeoftestingwiththeDTXCableAnalyzerview.

ThetestercanshowtheOTDRresultsinthree formats(Figure 12):• Tableshowsatableoftheeventsonthefiber.

Usethisscreentoquicklyseemeasurementsforalleventsandseethetypesofeventsonthefiber.Thetableincludesthedistancetotheevent,thelossoftheevent,thesizeofthereflectionfromtheeventandthetypeoftheevent.Toseedetailsforanevent,taptheeventinthetable.

• EventMap™ showsadiagramoftheeventsonthefiber,thefiberlengthandtheoveralllossofthefiber.Usethisscreentoquicklylocatecon-nectorsandfaultsonthefiber.Toseedetailsforanevent,taptheeventinthemap,thentaptheinformationwindowfortheevent.

• TraceshowstheOTDRtrace.Usethisscreento seethedeadzonesofreflectiveeventsandexaminethecharacteristicsofunexpectedeventssuchasghostsandgainers.

– ThecharacteristicsofthelinkwillshowintheEventMap

– Note:Testresult(Pass/Fail)andeventsshowndependonthecharacteristicsofthetestlink

– Tap“SummaryBubble”tolookatthedetails

EventMap™ View–Infigure 13isanexampleofaPASSINGtestusinglaunchandtailfiber• Differenticonsdistinguisheventssuchas:

– Passingreflectiveevent

– Failingreflectiveevent

– Hiddenreflectiveevent

– Passinglossevent

– Failinglossevent

– Hiddenevent’slossisaddedtopreviousevent’sloss

• Detailsareprovidedfortheevent’sloss,reflectanceandsegmentattenuation.

Figure 15 – Connecting OTDRs to installed fiber using launch fiber compensation

Figure 13 - OptiFiber Pro EventMap™ example, by tapping on bubble to drill in for more information

Figure 14 - OptiFiber Pro TRACE example

Figure 12 - OptiFiber Pro TABLE example

1716

OTDR certification set-upSetting up for OTDR Certification TestingSetup:Turntherotaryswitchto“Setup”andchoose“Settings”frommenusinfivesetupscreens.1.First,selectwhichportyouwanttotestfrom

(multimodeorsinglemode),whichtestlimityouwanttouse,thefibertypeanddesiredwavelength.• ItispossibletocreatemultiplesetsofOTDR

testlimitsandselectoneforaparticularjob.EachOTDRtestpasses(Figure 16)orfails(Figure 17)basedonacomparisonagainsttheselectedsetoftestlimits.

2.Onthesecondsetupscreen,youcansetlaunchfibercompensation,designatewhichendyouaretestingfromandnotewhatyouwanttocalleachendofthefiber.

Using launch fiber compensation (LFC) Launchfibercompensationisusedtosimplifytestingandremovethelaunchandreceivefibers’lossesandlengthsfrommeasurements(Seefigure 15).• Itshowswhereyourlaunch(and/orreceive)

fiberisonthetrace,andeliminatesitfromthecertificationtestresults.Ifyouareacontractor,yourcustomerswanttoknowwhereaneventis intheirfiberplant,notwhereitisonyourtestsetup.Whenyouenable“LFC”,aconnector50mfromthepatchpanelwillshowupat50m,not150monthetrace.Justturntherotaryswitch to“Setup”,gotothesecondtabandenable “LaunchFiberCompensation”.Thenturnitagain to“SpecialFunctions”,andchoose“SetLaunchFiberCompensation”.Choose“Launch”onlyifyouarejustusingalaunchfiber,or“OtherOptions” ifyouarealsousingareceivefiber.

3.Third,designatethefibercharacteristics,allowde-faulttotheselectedfiberinthefirststeporchoose“UserDefined”andselect“Numeri-calAperture”and“Back-scattercoefficient”forthefiber-under-test.

4.Nowchoosefromthemenutoset“DistanceRange”,“AveragingTime”.

5.Finally,choosefromthemenutoset“PulseWidths”and“LossThreshold”. WiththeDTXCompactOTDR,manysettingssuchas“DistanceRange”,“AveragingTime”,

“PulseWidths”and“LossThreshold”canbeautomaticallyset.Justturntherotaryswitchto“Autotest”andwhenyoupushthe“Test”button,theOTDRwillchoosethemostappropriatesettingforthefiberyouaretesting.

Running an autotest.Nowthatyou’reallsetupfortesting,turnthedialto“Autotest”,pluginyourlaunchfiberandpress“Test”.Ifitpasses,press“Save”,namethetestandtestthenextfiber.Ifyouwanttoseeatrace,justpressthef1softkey.Theeventtableandlimitsarealsoaccessibleviasoftkeysonthemainscreen.

Summary of extended certification

• OTDRtracescharacterizetheindividualcomponentsofafiberlink:connectors,splicesandotherlossevents.Extendedcertificationcomparesthedatatospecificationsfortheseeventstodetermineiftheyareacceptable

• Criticalbecauseitidentifiesfaultsthatmaybeinvisibletobasiccertification

• Evidencethateverycomponentinafiberopticcablingsystemwasproperlyinstalled.SeePassresultat1550nminfigure 18andat850nminfigure 19

Figure 19 – “Pass” trace screenshot on the DTX Compact OTDR

12 13

N E T W O R K S U P E R V I S I O N

Setting up for OTDR Certification Testing

Setup: Turn the rotary switch to ‘Setup’ and choose ‘Settings’ from menus in five setup

screens.

1. First, select which port you want to test from (multimode or singlemode), what test

limit you want to use, the fiber type, and desired wavelength.

• ItispossibletocreatemultiplesetsofOTDRtestlimitsandselectonefora

particular job. Each OTDR test passes (Figure 6) or fails (Figure 7) based on a

comparison against the selected set of test limits.

2. On the second setup screen, you may then set launch fiber compensation, designate

which end you are testing from, and notate what you want to call each end of the fiber.

Using launch fiber compensation (LFC)

Launch fiber compensation is used to simplify testing

and remove the launch and receive fibers’ losses and

lengths from measurements.

• Itshowsyouwhereyourlaunch(and/orreceive)

fiber is on the trace, and eliminates it from the

certificationtestresults.Ifyouareacontractor,

your customers want to know where an event

is in their fiber plant, not where it is on your

test setup. When you enable ‘LFC’, a connector

that is 50m from the patch panel will show up

at 50m, not 150m on the trace. Just turn the

rotary switch to ‘Setup’, go to the 2nd tab, and

enable ‘Launch Fiber Compensation’. Then turn

it again to ‘Special Functions’, and choose ‘Set

Launch Fiber Compensation’. Choose ‘Launch’

only if you are just using a launch fiber, or

‘Other Options’ if you are also using a receive

fiber.

3. Third, designate the fiber characteristics or allow

default to the selected fiber in the first step or

choose ‘User Defined’ and select ‘Numerical

Aperture’ and ‘Back-scatter coefficient’ for the

fiber-under-test.

4. Now choose from the menu to set ‘Distance

Range’, ‘Averaging Time’.

5. Finally, choose from the menu to set ‘Pulse Widths’

and ‘Loss Threshold’.

With the DTX Compact OTDR, many settings such

as ‘Distance Range’, ‘Averaging Time’, ‘Pulse

Widths’, and ‘Loss Threshold’ can be automatically

set. Just turn the rotary switch to ‘Autotest’, and

when you push the test button, the OTDR will

choose the most appropriate setting for the fiber

that you are testing.

Running an autotest. Now that you are all set up

for testing, turn the dial to ‘Autotest’, plug in your

launchfiberandpress‘Test’.Ifitpasses,press’Save’,

namethetest,andtestthenextfiber.Ifyouwantto

see a trace just press the f1 softkey. The event table

and limits are also accessible via softkeys on the

main screen.

Summary of extended certificationOTDR traces characterize the individual compo-•nents of a fiber link: connectors, splices and other loss events. Extended certification compares the data to specifications for these events to deter-mine if they are acceptable

Critical because it identifies faults that may be •invisible to basic certification

Evidence that every component in a fiber optic •cabling system was properly installed

Figure 6 – “Pass” Screen on the DTX Compact OTDR

Figure 7 – “Fail” Screen on the DTX Compact OTDR

Figure 8 – Trace Screenshot on the DTX Compact OTDR

Figure 9 – “Pass” Trace Screenshot on the DTX Compact OTDR

Figure 18 – Trace screenshot on the DTX Compact OTDR

Figure 17 – “Fail” screen on the DTX Compact OTDR

Figure 16 – “Pass” screen on the DTX Compact OTDR

1918

Aswiththefirsttieroftesting,youcandownloadtestresultstoaPCandmanagethemwithLinkWareResultsManagementSoftware.ItiseasytomergeOTDRtestresultswiththeotherrecordsifthesamenamingsequenceisused.Thesecanbeeasilycreated,printedoremailedasPDFfiles.

Cable certification test strategyThereareseveralwaystoperformacompletecertificationtestoffiberopticcabling.Thestandardsareclearaboutdefiningrequiredandoptionaltests,testlimitsandacceptabletestequipment.But,theydon’tsuggesthowthetestingshouldbeperformedforoptimumefficiencyinthefield.Basedondecadesofworkwithcon-tractors,installersandtechnicians,FlukeNetworksdevelopedproven,best-practiceprocedurestoperformacompletefibercertificationinthemostefficientway.

• Makesuredesigncriteriaandtestlimitsareestablishedbeforeinstallation

• Confirmproperfiberstrandpolarity,end-faceconditionsandverifylosswithsimpleverificationtoolsduringinstallation

• Performextendedtestsusingthetier2certificationtests(OTDRanalysis)asthefirstcertificationstep.Doingso:

– Ensuresconnectorperformancmeetsgenericcablingstandardsorsystemdesigner’srequirements.

– Qualifiesworkmanshipforcablinginstallation.

– IdentifiesproblemsforimmediatetroubleshootingwithOTDR.

• Secondly,performbasictier1testforthechannelagainsttheapplicationstandard.Thiscertifieschannellengthandlossandcalculatesmarginbasedonthestandard

• Ifbidirectionaltestingisn’trequired,measurechannellossatthewavelengthoftheapplication

5. Finding and Analyzing Fiber Cabling Faults

Common FaultsInsufficientpowerorsignaldisturbancesfromcommonfaultscausefailuresinopticaltrans-mission.

Fiberopticconnectionsinvolvethetransmis-sionoflightfromonefibercoreintoanother.Fibercoresaresmallerthanthediameterofahumanhair.Tominimizelossofsignalpower,thisrequiresgoodmatingoftwofiberend-faces. • Contaminated fiber connections–Theleadingcauseoffiberfailuresispoorconnec-

torhygiene.Dust,fingerprintsandotheroilycontaminationcauseexcessivelossandpermanentdamagetoconnectorend-faces

• Too many connections in a channel–Simple,butitisimportanttoconsiderthetotalallowableloss(perintendedapplicationstandard)andtypicallossforconnectortypeduringthedesignprocess.Eveniftheconnectorsareproperlyterminated,iftherearetoomanyinachannel,thelossmayexceedspecifications

• Misalignment–Thebestwaytoachievegoodfiberalignmentistofusethetwofiberstogetherwithaprecisionsplicingmachine.Butforseveralpracticalreasons,connectionoffibersisoftendonemechanically.Therearemanycommerciallyavailableconnectortypesandallhavetheiradvantagesanddisadvantages.Typicallossspecificationsareagoodproxyforhowwelltheycantoalignfibers.Specificationsusedfordatacommuni-cationsshouldbecompliantwithFiberOpticConnectorIntermatibilityStandard(FOCIS)standards

– Poor quality connectors or faulty termination–Goodqualityconnectorshaveverytighttolerancesinordertomaintainprecisealignment

– End-face geometry–Performanceoffiberopticconnectorsislargelyafunctionofthegeometryoftheend-face.Thisgeometrycanbemeasuredinalaboratorywithprecisioninterferometryequipment.Inthefield,thefollowingparametersareinferredinlossandreflectancemeasurements

• Roughness–Scratches,pitsandchipsproduceexcesslossandreflectance

• Radius of curvature–Theconvexsurfaceoftheconnectorshouldnicelymateupwithanotherconnector

• Apex offset–Thecoreofthefibershouldbecenterednearthehighestpointoftheconnector

• Fiber height–Aprotruding(underpolished)fiberdoesn’tmatewellandanundercut(overpolished)connectorwillperformpoorlyduetoanairgap

– Unseated connectors – Aconnectormaybepluggedintoanadapterbulkhead, butmaynotbeseatedandconnectedwithitsmate.Wornordamagedlatchingmechanismsonconnectorsoradaptersaresometimestheculprit

– Poor cable management–Strainonaconnectormaycausemisalignmentduetobecomingpartiallyretracted,brokenorunplugged

Figure 21 – Example of a common cause of a fiber failure

Figure 20 – Sample LinkWare Results Management Software report

2120

• Polarity–Perhapsthesimplestfibercablingfaultisareversaloftransmitandreceivefibers.Thisisusuallyeasytodetectandrepair.But,sometimes,connectorsaredu-plexedtogetherandmustbebrokenaparttobereversed.Standardsdesignatepolaritywithalabelingconventionthatisseldomused,resultinginconfusion

– PolarityshouldbedesignatedwithAandBlabelsorcoloredboots

– AisfortransmitandBisforreceive.OR,redisfortransmitandblackisforreceive

Poorcablemanagement,systemdesignordamagedcablealsocausesfaultsinfibercablingsystems.Fiberhasahightensilestrength,butissusceptibletocrushingandbreakingifabused.• Bends–Macroandmicrobendingcausedbytightcabletiesorbendradiusviolations

resultinexcessiveandunexpectedloss

• Breaks–Lightwillnolongerpropagatepastalocationwheretheglassiscrushedorcrackedinanopticalfiber

• Intersymbol interference (ISI)–DisturbedSignalisusuallytheresultofpoorsystemdesign.Asystemthatisn’tcertifiedwiththeapplicationstandardinmindissuscep-tibletoISI

– Modaldispersionfromviolationofdistancelimitationsonmultimodefibers

– Reflectionsfromtoomanyhighlyreflectiveconnectorscauseincreasedbiterrorsduetoexcessivereturnloss

Simple fault findingContinuityandpolarityproblemsfrombreaksorunlatchedconnectorsarecommonandsometimesdifficulttolocateandidentifywithlosstesters.Visualfaultlocatorsandopticalfaultfinders,likeFlukeNetworks’FiberQuickMapandFiberOneShotPROarerecom-mendedtofindbreaksorunpluggedconnectorsinafiberlink. Afibertroubleshooterquicklyandefficientlylocatesconnectionsandbreaksineithermul-timodeorsinglemodefiber.Assingleendedtesters,launchcablesarerecommended.SimplyplugtheFiberQuickMap(shownatright)intooneendofafiberchannelandpressTestbut-tontoreveallocationsofincidentsofinterest,confirmchannelconnectivityanddistancetofailures.Lasers,suchastheVisiFault,providethesimplesttroubleshooting.Justshineitdownafiberlinkandcheckthefarendorvisualsignsofhighloss.

Advanced troubleshootingOptiFiber Pro offers advanced troubleshooting features:Whenatestiscompleted,thewindowshowstheeventwiththeworstmeasurement.Iftheborderisgreen,themeasurementsfortheeventdon’texceedlimits.Iftheborderisred,ameasurementexceedsthelimits.Iftheborderisblue,thetesterdoesn’tassignapassorfailresultbecauseitcan’tdoafullanalysis.ThisoccursforOTDRPort,HiddenandEndevents.Whenyouuseatestlimitwithareflectancelimit,Hiddeneventsshowafailstatusiftheirreflectanceexceedsthelimit.Toseedetailsfortheevent,tapthewindow.Toseeinformationforanotherevent,tapanothericononthemap.Note:Eventsbeforethelaunchcordconnectorandafterthetailcordconnectordon’thaveapassorfailstatus.

TheoptionalvideoprobeconnectstotheUSBAportontheOptiFiberProtestertoletyouinspecttheendfacesinfiberopticconnectors.Theprobeletsyouseedirt,scratchesandotherdefectsthatcancauseunsatisfactoryperformanceorfailuresinfiberopticnetworks.

a.TurnONtheOptiFiberPro.Youwillseethe Homescreen,selectTools(seefigure 23)

b.ConnecttheInspectorProbetotheUSBport toOptiFiberPro

c.Tap“Tools”

Figure 23 – Main Menu - Tools Option

Figure 22 – EventMap diagnostics

2322

TheFaultMaptest(shownin Figure 24)helpsyourecordtheconnectionsinafiberlinkandidentifybadconnections.Itcanshowshortpatchcordsandfindconnectionsthathavehighreflectance.TheFaultMaptestgivesyoutheseresults:

• ShowsamapoftheconnectorsinthelinkmightnotshowontheOTDREventMap.Themapincludesconnectorsthatarehiddeninthedeadzonesmadebypreviousevents.TheFaultMaptestshowspatchcordsasshortas0.5mforlengths<2km.

• Highlightsconnectionsthatarepoorduetohighreflectance(>-35dB).Reflectiveeventsthatareapparentlynotconnectorsdon’tshowontheFaultMapdiagram.Losseventsarealsonotshown.TheFaultMaptestfindseventsthathaveareflectancelargerthanapproximately-50dBonmultimodefiberand-60dBonsinglemodefiber.(Morenegativevaluesmeanlessreflectanceandabetterconnection.Forexample,aconnectorwithareflectanceof-40dBisbetterthanonewith-35dB.)

Troubleshooting basicsTherearesimplewaystoavoidcomplextrouble-shootingexercises.Ifyoufollowthesebestprac-tices,youwon’tspendasmuchtimefaultfindingandperformingOTDRanalysis.

• Keep it clean–Dirtyconnectionsarethebiggestcauseoffailingconnectionsandtestingchal-lenges.Cleanfiberseachtimetheyareconnected.Youcanverifyfibersarecleanbyusinganinstru-mentsuchasaFiberInspector microscopetoexaminefiberendfaces.

– Dustblockslighttransmission

– Fingeroilreduceslighttransmission

– Dirtonfiberconnectorsspreadstoothercon-nections

– Contaminatedend-facesmaketestingdifficult

– Remembertoinspectequipmentportslikerouters,switchesandNICs.Theygetdirtytoo

• Use the right test setup–Teststandardperspecificationswillensureyougetthemostac-curate,consistent,understandableandrepeatableresults

• Use recommended fiber mandrels –toimprovelossmeasurementaccuracyandrepeatability

• Always use high-quality TRCs and launch fibers–Avoidrandom,questionablequality testcords

– AllTRCsforlosstestingshouldbedeliveredwithgoodtestresultdata

– Testcordsshouldmakepolarityeasyforyou.FlukeNetworks’cordsfeatureredbootsontheendwherelightentersandblackbootsontheendwherelightexits

– Keepcordscleanandreplacethemwhentheyshowsignsofwear

• Choosetestlimitsappropriatetobothgenericcablingstandardsand applicationstandards

6. End-Face Inspection and CleaningInspectionProperinspectionhelpsdetecttwoofthemostcommon(yeteasiesttoprevent)causesoffailure:damagedanddirtyfiberend-faces.

Damageoccursintheformofchips,scratches,cracksandpitstothecoreorcladdingandcanresultfrommatingcontaminatedend-faces.Tinyforeigndebrisleftonthecorecanalsodamageend-facesastheyareconnectedtogetherduringthematingprocess.

Asalludedtoearlier,sourcesofcontaminationareeverywhere,whetherfromthetouchofafingerorthebrushofclothing,muchlesstheomnipresentdustorstatic-chargedparti-clesintheair.Portsarealsosubjecttothesamecontamination,butareoftenoverlooked.Matingacleanconnector,toadirtyportnotonlycontaminatesthepreviouslycleancon-nectorbutcanalsocausefiberdamageorfailure.Eventheprotectivecoveringsor“dustcaps”onstraight-from-the-packageconnectorsandassembliescancausecontaminationduetothenatureoftheproductionprocessandmaterials.

Manypeopleassumeaquickvisualcheckoftheend-facesissufficienttoverifycleanli-ness.Asmentionedpreviously,thecoresofthesefibersareextremelysmall–rangingfromroughly9to62.5µm.Putintoperspective,withadiameterof90µm,theaveragehumanhairisanywherefrom1.5to9timeslarger!Withsuchatinycoresize,it’simpossibleforend-facedefectstobespottedwithouttheaidofamicroscope.(Seefigure 25 and 26 forsetupandendfaceexamples)

Figure 26 - FiberInspector results view

Figure 25 - FiberInspector set up from Tools menu

Figure 24 - FaultMap results view

2524

There are two types of fiber inspection microscopes:• Optical (Figure 27)–tube-shapedandcompact,they

enableyoutoinspecttheend-facesdirectly.Popularbecausetheyareinexpensive.However,theyaren’tabletoviewend-facesinsideequipmentorthroughbulkheads.

• Video (Figure 28)–smallopticalprobeisconnectedtoahandhelddisplay.Theprobesizemakesthemexcellentforexaminingportsinhard-to-reachplaces;largedisplaysenableeasyidentificationofend-facedefects.Theyarealsosaferastheyshowanimage andnottheactualend-facebeingobserved,reducingtheriskofexposingone’seyetoharmfullasers.

Whenitcomestoshowingtheuserwhatthenakedeyecan’tsee,thebestmicroscopeistheonethatcandetectthesmallestobject.

CleaningProperlycleanedend-facescanactually“add”upto1.39dBontoyourlossallowance(Figure 29). Inotherwords,ifyouhaveafiberplantwithanoveralllossof5.0dBagainstaspecifiedbudgetof4.5dB,cleaningdirtyend-facesmaydropthelinklossdowntojustabove3.6dB,providinga“Pass”andplentyofhead-room.Consequently,it’simportanttochooseyourcleaningtoolsandmethodswiselywhileavoidingcommonbadhabits.Perhapsthemosttypicalmistakeisusingcannedairtoblastfibercon-nectorsorports.Whilehelpfulfordisplacinglargedustparticles,itisineffectiveonoils,residuesortinystatic-chargedparticlesequallydetrimentalincausingfailures.

Thesameproblemoccurswhenusingshirtsleevesor“clean”clothstowipeconnectors.Infact,thetraceamountsoflintanddust-attractingstaticfromthesematerialswilllikelyaddcontamination,ratherthanreduceit.Evenisopropylalcohol(IPA),whichhashistori-callybeenanacceptablesolvent,isprovingtobeinferiortospeciallyformulatedsolu-tions.IPA’sinabilitytodissolvenon-ioniccompoundssuchaspullinglubeandbuffergel,

andtheresidueitleavesafterevaporationmakeengineeredsolventsthesuperiorchoice.Whenusingthesesolvents,thepropercleaningorderis“wettodry”usingclean,lint-freewipes(Figure 30).

Cleaningresourcesvaryincomplexityandprice,rangingfromsimplewipestodevicesthatincorporateultrasoundwithwater.Whichtoolyouusedependsonneedandbud-get.Butforthemajorityofthecablingjobsandprojects,lint-freewipesandswabswithengineeredsolventsnowfoundinfiberinspection,certification,andcleaningkitswillbesufficient.

7. Conclusion Cablinginstallationisamulti-stepprocess.Itisprudenttocertifythecablingsystemafterinstallationtoensureallinstalledlinksmeettheexpectedlevelofperformance.Cer-tificationwilllikelyidentifysomefailingormarginallypassingresults.Inordertodeliverahigh-qualitycablingsystem,defectsthatcausefailuresandmarginalpassesmustbeuncoveredandcorrected.

FlukeNetworks’fullsuiteoffibercertificationinstruments(Appendix2)hasanunparal-leledhistoryofprovidinguniqueandpowerfuldiagnosticsassistancetoinstallationtechnicians.Byknowingthenatureoftypicalfaultsandhowthetester’sdiagnosticsreportthem,youcansignificantlyreducethetimetocorrectananomaly,aninstallationerrororadefectivecomponent.Personnelresponsiblefornetworkoperationalsobenefitfromthediagnosticcapabilitiesofacertificationtesttoolbyreducingnetworkdowntime.

Werecommendyoufamiliarizeyourselfwiththecapabilitiesofyourtesttool.Ittrulyismodestinvestmentthatpaysforitselfmanytimesover.Inadditiontoyourprecisioninstrument,FlukeNetworksalsoprovidesawidevarietyofexpertandtimelysupportop-tions.Whetheryouareaninstaller,networkownerorcontractor,thefollowingresourcesareavailable:

• White papers and Knowledge Base articles–insightfulstudiesandhelpfuladviceonrelevantstructuredcablingtopics

• Unsurpassed technical assistancefromthehighlytrainedFlukeNetworksTechnicalAssistanceCenter(TAC)

• Certified Test Technician Training (CCTT) classesavailablearoundtheworld

• Gold Support program –comprehensivemaintenanceandsupportincludingpriorityrepairwithloaner,annualcalibrationandpriorityTACsupportwithafterhoursandweekendcoverage

Figure 30 – “Wet to dry” cleaning methodology. Ap-ply a small spot of solvent to the starting edge of a wipe. Holding the end-face connector perpendicularly, swipe the end-face from the wet spot to the dry zone.

Clean fiber end-face

Contaminated fiber end-face

Figure 29 – Comparison between a clean and dirty fiber end-face

Figure 27 – Optical microscope

Figure 28 – Video microscope

2726

8. GlossaryCertification testing–theprocessoftestingthetransmissionperformanceofaninstalledcablingsystemtoaspecifiedstandard;requiresanOLTSfor“Tier1”certificationandanOTDRfor“Tier2”certification

Channel –end-to-endtransmissionmediumbetweenatransmitterandreceiver

dB–functionofaratiooftwopowerlevels,typicallyusedtoexpresstherelationoftheoutputpowertotheinputpowersuchasthegaininanamplifierorthelossina transmissionline

dBm–powerlevelexpressedasthelogarithmoftheratiorelativetoonemilliwatt

FiberInspector–FlukeNetworks’popularlineofhandheldfiberend-faceandbulkheadportinspectioninstruments,rangingfromtubetovideomicroscopes

Gbps–gigabitspersecond

Launch cord fiber–lengthoffiberplacedbetweenthelink-under-testandtheOTDRtoimprovetheOTDR’sabilitytogradethenear-endconnectorandanyabnormalitiesinthefirstconnection

LED–LightEmittingDiode,arelativelylow-intensitylightsource

Link–thephysicalcablingforatransmission

Mbps–megabitspersecond

OLTS–OpticalLossTestSet,abaseline“Tier1”certificationinstrumentthatmeasuresthelossofalinkoveritslength

LSPM –LightSourcePowerMeter,basicfiberverificationinstrumentcomposedofapowermeterandasourcetomeasurelossoveralink

TRC–TestReferenceCord,ahigh-qualityfibercord,1to3meterslong,with high-performanceconnectors,ideallywithend-faceswithspecialscratchresistanthard-enedsurfacesthatenablenumerousinsertionswithoutdegradationinlossperformance

VCSEL–VerticalCavitySurfaceEmittingLaser,commonlyusedinmultimodelightsources

Verification testing–theprocessoftestingthetransmissionperformanceofaninstalledcablingsystemtoensureitmeetsaminimumthreshold

VFL–VisualFaultLocator,opticalsourcethattransmitsalow-poweredlasertoidentifybreaksinfiberlinks

Ap

pe

nd

ix –

Flu

ke

Ne

two

rks

Fib

er

Test

an

d T

rou

ble

sho

oti

ng

In

stru

me

nts

Insp

ecti

on a

nd C

lean

ing

Loss

Len

gth

Test

ing

(Tie

r 1

Cert

ifica

tion

)Pl

ant

Char

acte

riza

tion

& T

roub

lesh

ooti

ng

(Tie

r 2

Cert

ifica

tion

)

Vis

iFau

lt V

isu

al

Fau

lt L

oca

tor

Fib

erIn

spec

tor

Pro

/Min

i Vid

eo

Mic

rosc

op

es

Fib

er O

pti

c

Cle

anin

g K

its

Mu

ltiF

iber

Pro

Sim

pliF

iber

Pro

Po

wer

Met

er a

nd

Fi

ber

Tes

t K

its

DTX

-CLT

C

erti

Fib

er O

pti

cal

Loss

Tes

t Se

t

DTX

C

able

An

alyz

er

wit

h F

iber

M

od

ule

s

Fib

erQ

uic

kMap

DTX

C

able

-An

alyz

er

wit

h C

om

pac

t O

TDR

Mo

du

le

Op

tiFi

ber

Pro

O

TDR

Chec

k fo

r fib

er e

nd-f

ace

cont

amin

atio

n or

dam

age

33

Clea

n co

ntam

inat

ion

3

Chec

k co

nnec

tivi

ty3

MPO

33

33

33

Chec

k po

lari

ty3

33

33

Veri

fy lo

ss o

ver

enti

re li

nk t

o en

sure

lo

ss b

udge

t no

t ex

ceed

ed3

33

33

3

Dual

-fibe

r lo

ss t

esti

ng3

3

Tier

1 c

erti

ficat

ion

33

3

Loca

te f

ault

s3

33

3

Loca

te m

ulti

ple

conn

ecti

ons

and

loss

eve

nts

33

3

Mea

sure

eve

nt lo

ss3

3

Refl

ecta

nce

mea

sure

men

ts3

33

Tier

2 c

erti

ficat

ion

33

Pass

/fai

l res

ults

33

33

3

Docu

men

t te

st r

esul

ts3

33

33

3

Sour

ce t

ype

Lase

rLE

DLE

D,F

PLa

ser

LED,

FP

La

ser,

and

VCSE

LLE

D,F

P

Las

er,an

dVC

SEL

LED

LED,

FP

Lase

rLE

D,F

PLa

ser

28

Fluke NetworksP.O. Box 777, Everett, WA USA 98206-0777

Fluke Networks operatesinmorethan50coun-triesworldwide.Tofindyourlocalofficecontactdetails,goto www.flukenetworks.com/contact.

©2012FlukeCorporation.Allrightsreserved.PrintedinU.S.A.9/20123481323C

YourauthorizedFlukeNetworksdistributor

Formoreinformation,pleasevisit www.flukenetworks.com