SpeedmatchinglocoswithaSPROG,DecoderProandAccutrackSpeedometer

PreparationIuseanovaloftrack,madeupof8curvedsectionsand6straightequivalents(allowingforpowerconnectors,andrerailersectionsforconvenience)madebyKato.First,makesurethatthetrackissetupandconnectedright,andisclean.Next,checkthatalllocosthatwillbespeedmatchedarerunningasexpected.Runeachlocofor5minutes,slowandfast,forwardandreverse,tomakesureeverythingisasexpected.Ifanylocoiswildlyoutofspeedwiththeothers,itisacandidateforsomeservicing.Randomhesitancyisusuallyasignofwheelsortrackneedingcleaning.Anylocothatisreluctanttostartatlowspeedstepsshouldhaveitskick–startvoltage(ifsupportedbythedecoder)adjusteduntilitjuststartstomoveatspeedstep1.Ideally,alllocoswillcrawlveryslowlyatstep1,runatthedesiredmaximumspeedatfullthrottle,andhavealinearspeedcurveinbetween.Theproceduredescribedherewillenableyoutoadjustanylocosthatdonotmeetthat,inordertobeascloseasispracticaltotheotherlocoswithwhichtheywillberequiredtowork.

TypicalUsagesAgeneral-purposemainlinefreightlocoonmostrailwayswillneedtorunatupto60-75mph,andhavegoodspeedlinearityfrom0-75.Expresspassengerlocoscanhavehighertargetspeeds,whileaswitcherwillnotberequiredtoexceed25mphinmostcases,butwillwantveryfinespeedcontrolatthelowerendofitsspeedrange.Selecttherightusageforaloco,andsetitupforthemostusefulspeedrangetomeetthatneed.TheAccutrackspeedometerisacompactunitthatsitsoverthetrack,andwillgivetheabilitytosetthetopspeedofthelocostotheplannedscalespeed,andthenmatchintermediatepointstogetconsistentbehaviorofallthelocosacrossthewholespeedrange.Ofcourse,itispossibletomatchtwolocostoeachotherwithoutaSpeedometer,andtomeasurescalespeedsbytimingthelocooveraknowndistance,butthisSpeedometerunitmakesthewholetaskmucheasier,andmoreenjoyabletoo!

SPROGandDecoderProSetupTheSPROGandDecoderProareinstalledasdescribedinthestandardinstructions.IaminitiallydescribingusingtheProgrammingMode(alsocalledServiceModeinDecoderPro)tosetupeachlocomotiveindividually.InDecoderPro,makesurethatyouhavealllocosintheroster.Thisisverysimpletodoifyouhavenotalreadydonethis;justputthelocoonthetrack,andclickNewLoco.Runthroughtheselectionsteps,andsavethedetailswithaunique“ID”.OncesavedintheRoster,itiseasytorecallthesettingsforthatlocoandreusethem.Thentouseanyloco,putitaloneontrackandclickIdentify.

Oncethelocoisrecognized,clicktheProgrambuttontoopentheProgramviews,andselecttheSpeedTablepane.NowalsoopenaThrottle;gobacktotheRosterwindowandclicktheThrottlebutton,orpickNewThrottlefromtheActionsmenu.DuringthisprocedurewewillswitchbetweentheThrottle(torunthelocos)andtheProgramSpeedTable(toadjustsettings)numeroustimes,andsoyouwantthemonscreentogether.

ExampleFormyfirstexample,IamsettingupanNScaleF7pairofAandBunitstorunaspassengerlocosforthehistoricSantaFetrains.TheseF7unitswereoriginallyratedfor100mphmaximumoperatingspeed,andsoIwilladjustthesetomeetthatrange.Inthiscase,theAunithasaDigitraxdrop-indecoderDN163K0B,andtheBunithasthesamedrop-in.Onfirstrunning,bothAandBunitsranatwellover100scalemphevenatmidthrottlesetting,andsoafirststepistoadjustthetopspeedtomeetthe100mphtarget.IstartedtheadjustmentprocedurewiththeF7Aaloneonthetrack.Withbothviewsonscreen,Iturnedonthetrackpower(showinggreenatthetopoftheThrottleview)andsetthespeedwiththeslider.Theinitialspeedcurveshowedlineardefaultsettings,andsoafirststepwastopulldowntherighthandslidertoanapproximateestimateofthedesiredpointtodeliver100mphatfullspeed.Todothis,itisnotnecessarytostoptheloco,orturnofftrackpower.JustclickintheSpeedTablewindow,andadjusttheslidertosuit.

NotehereIhaveonlypulleddowntherighthandslider,andasitreduces,soDecoderProsuccessivelyreduceseachlowerslidertoo.Thisensuresthathigherstepsequatetohigherspeedsettings,andyoudon’tendupwithstrangecurves!ThenclicktheWriteChangesonSheetbutton,andthelocowillstop,theprogrammingwilloccur,andyouwillseethesliderschangecoloraseachprogrammingsteptakeseffect.Whenallslidershaveclearedthecolor,showingthewritewassuccessful,clickintheThrottlewindowagain,andthenturnontrackpowerbyclickingthe(nowred)powerbutton.Iselected90outof255asafirsttry,andthenrantheloco

again.Stilltoofast,andsoaprogressionofreducingthesettingofthetopSpeedTableentry,andretrythecircuitaroundthelooparrivedat72astherightsettingfortopspeed.Nowtosetamiddlepointspeed,weneedtoalignthoseslidersintoamorenormalslope.Therecanbereasonstohavedifferentshapedcurves,butthisexampleofaflatspeedprofileforallstepsaboveabout30%wouldnotbeaverylikelychoice.Seelaterinthisarticleformoreaboutthevalueofsomeother

curves.Toalignthespeedsteps,justclicktheMatchEndsbutton,andDecoderProwillsetallthesliderstoastraightlinebetweenthebottomendsettingandournewlyselectedtopspeed,inconceptgivingusalinearspeedcurveandsoweshouldexpect50scalemphat50%throttle.WriteChangesonSheetagain.Testingthislocoat50%showedasignificantlyhigherspeedat50%throttle,andsonowwewanttoadjustthecurvesevenlytogivetherightmid-pointspeed,withoutaffectingtheendpoints,orintroducinganyflatareasagainwithnodifferencesbetweensteps.

TheSpeedTableincludesaveryeffectivemechanismtodothisintheformofthesmallcheckboxesatthebottomofeachslider.Checkthefirstandlastboxestoholdthosepositions,andthenwewanttomovethemidpoint.Checkthatboxaswell,andthenwhenmovingthesliderforstep14,DecoderProwillmaintainastraightlinebetweenthereandeachendpoint(whichwearenotmoving).WriteChangesonSheetoncemore,andrunthelocoagaintocheckthatadjustmenthasmetourgoals.Inthiscase,thespeedsrequiredarenowprogrammedintotheloco,andsowecanclosetheProgramactivity,andsavethesettingstotheRoster.WhenclosingtheSpeedTableview,youwillseeaboxshowing“thesesettingshavenotbeensavedtotheConfigurationFile”andaskingifyouwishtosave.SelecttheSaveandClosebutton,andtheRosterentrywillbeupdated.

ThenextlocoFortheBunit,asthishasanidenticaldecoderinit,Iwasabletouseasimplificationtotheprocess.IjustsetbothAandBunitstothesamedecoderaddress,andusedthesameinitialRosterentryforboth.MyfirststepwastoaccesstheBunitlocoasabove,andthenselecttheSpeedTablepaneandwritetheFullSheet.Thisshouldsetbothlocostosimilarperformance.Althoughthesearenominallyidenticalmechanismsandexactlythesamedecodertype,theBunitranmoreslowly,andincreasingthestep28valueto74wasrequiredtoget100mphthroughtheSpeedometer.Thenadjustingthevalueofstep14downto36deliveredthedesiredspeedat50%.

SavingthosevaluesOfcourse,nowIhavetwodifferentsetsofSpeedTablevalues,andI’llwanttokeeptrackofthat.So,temporarilyIcandiscardthechangesImadefortheBunitintheRosterentryIamusing,whichwascreatedfortheAunit.Closetheprogramviews,anddonot“savetotheConfigurationFile”thechangesmadeinprogrammingtheBunit.IntheRosterview,selecttheitemfortheAunitloco,right-clickonitandselectDuplicate.GiveitanewIDname,andyounowhaveaRosterentryforthesecondunit.Selectthatentry,opentheProgramview,selecttheSpeedTable,andReadFullSheettoimportthevaluesfromtheloco.Closeandthistimedo“savetotheConfigurationFile”.Nowyouhavesavedtheactualvaluesforeachlocoandcanadjustasneededinfuture.Nowthefinalcheck;runbothlocosatselectedspeedstepsacrosstherangeandlookforclosingoropeningspacingbetweenthem.Forlocosneedingdifferentaddresses,nowisthetimetoresetthose.

Threepointspeedsettings,orSpeedTableSomedecoderssupportSpeedTables,somesupportMin,Maxandmidpoint‘voltage’settings,sohaveonlyMinandMax,andsoitisimportanttocheckwhatyourselecteddecodercansupportbeforestartingonSpeedmatching.Intheexampleabove,althoughtheseDigitraxdecoderssupportbothSpeedTableandall3points,IchosetousetheTable,butuseditasifIwerejustsettingtheMin,MaxandMidvalues.ThesametechniquesdescribedcanalsobeusedwiththeSpeedTabletocontrol–forexample–the25%and75%pointsorfinergranularity,andsoitisthemostflexibleoption.Asexplained,theeffortandtimetousethismethodisaboutthesameasthethreepointswouldbe.Afutureeditionofthisarticlewillcovermorefeaturesandseveralotherexamples.SPROGDCC,fromtheBBMGroup.http://sprog.us.com June2016