ToVoiceProjectDateSeptember30,1983FromL.StewartLocationPARCSubjectLarkRegistrationOrganizationCSLXEROXIntroductionAnEPROMfortheLarkhasbeendevelopedthatallowsthemachinetooperatestand-alonewithoutEthernetsupport.ThisEPROMisintendedforuseduringtelephoneregistrationtestingoftheLark.AsimpleuserinterfaceisprovidedwhichallowstheoperatortoplacetheLarkintoseveralconfigurationssuitablefortesting.ThisdocumentisfiledasLarkRegistrationEPROM.tioga.The"InitialConfiguration"Whenpowerisfirstturnedon,orwheneverthetelephonesetishungup,theLarkisestablishedinaninitialconfiguration.Theoutsidelineishungup.ThetelephonesetissetupsothatDTMFsignallingisdirectedtotheDTMFdecoderandsothatvoicefromtheoutsidelineissenttothetelephonesetreceiver.Sidetoneisenabled.TheoutputoftheCODECD/Aconverterisdirectedtotheoutsideline,tothespeaker,andtoLineOutB.VoicefromtheoutsidelineisdirectedtoLineOutAaswellastothetelephonesetreceiver.CommandsPoweron--setsupinitialconfiguration.Poweroff--"revert"relaysdropoutandpermituseoftelephonesetasastandardtelephone.Hanguptelephone--alwaysreturnsLarktoinitalconfiguration.Lifttelephonehandset--noaction,buttheDTMFkeypadisnotactivatedunlessthephoneisoffhook.DTMF1--pickuptheoutsideline.DTMF2--hanguptheoutsideline.DTMF3--recordthefollowingdigitsequenceasastorednumberofupto18digits.Thenumberisterminatedeitherbya'#orbyhangingupthephone.Anumberstoredinthiswayisremembereduntilanothernumberisrecordedoruntilpoweristurnedoff.p _/q1_/p(_/r3C_/:*9o<'@ :q@ !t$&Rt 7"  r 3L!'*%0u237s9<0?{@ G 2,  /Oq -6 |"T'" -P.458/<B:DF + F1 ##)y+17N8 )5 C!'){.0338;I=?E G 'l ' $U@$&=)x,E-/2n458)>@t !r Tc !$#&Q*-7.5F7c9:;? ]nN#e&(e+ j^j"%f',1g25R;?HAEG] ; v!&8 a Ev!  o T #)+i,0579;1=ADc " W H40YZU$&)./48:=H@A { 3>j V#')7-TVm$Inter-OfficeMemorandum2DTMF4--dialtherecordednumberusingtheCODEC.Thetonesaregeneratedatalevelofabout-3.5dBmpertoneattheoutsideline.DTMF5--turnonechomode.Moreaboutthislater.DTMF6--ConnectthemicrophonetotheCODECinputfortransmissiontothephoneline.DTMF7--ConnectLineInAtotheCODECinputfortransmissiontothephoneline.DTMF8--ConnectLineInBtotheCODECinputfortransmissiontothephoneline.DTMF9--"Revert"thetelephonesetsothatitisdirectlyconnectedtotheoutsidelineasastandardtelephone.SinceinthisconfigurationthetelephonesetisnolongerconnectedtotheDTMFdecoder,theonlywaytoreturntotheinitalconfigurationistohangupthetelephone.DTMF*--SetupthespeakertolistentotheoutsidelineinsteadoftheoutputoftheCODEC.DTMF0--ConnectthetelephonesettotheCODECinputfortransmissiontothephoneline.DTMF#--Ifanumberisbeingrecorded,thiswillservetoendit.Ifanumberisnotbeingrecorded,#hasthesameeffectashangingupandreturnstheLarktotheinitalconfiguration.EchoModeThissectionexpandsupontheexplanationoftheactionoftheDTMF5command.Commands6,7,8,and0connectvariousdevicestotheCODECinput"fortransmissiontothephoneline."Thewaythisworksisthatthesourceisfiltered,digitized,passedthroughthelevellimitingsystem,convertedbacktoanalog,filteredagain,andtransmittedtotheoutsidelineifitisoffhook.Alternatively,EchoModecanbeused.Inechomode,thestepsareexactlythesameexceptthatthedigitalvoiceisnotpasseddirectlyfromA/DtoD/A,butratherbufferedinmemoryforawhile.Theeffectofthisslightdelay,40milliseconds,istogivethevoiceaslight"echo"character.LimitingsystemTherearetwopathstotheoutsideline.Onepath,activewhenthepowerisofforwhenthe"Revert"modehasbeenenteredviacommandDTMF9,connectsthetelphonesetdirectlytotipandringoftheoutsideline.Inallothercases,voicedirectedtotheoutsidelineisproducedbytheD/AconverterofCODEC1.Thisconverterdrivesalowpassfiltertoensurethatnoout-of-bandcomponentsreachthephonesystem.Inaddition,thereisalimitingsystemwhichoperatesonthedigitalvoiceandservestopreventlevelshigherthan-9.5dBmfromreachingthephonesystem.Wheneverthelevel,averagedoverabout1.2seconds,reachesabout-9.5dBm,2.5dBoflossisinserted,reducingtheleveltoabout-12dBm.ThislimitingsystemisactiveatalltimesexceptduringDTMFsignallingoftherecordednumber.TheseDTMFtonesaretransmittedatabout-3.5dBmperfrequency.headNode,repeatasneeded,nestforsubheadsifappropriatebodynode,repeatasneededuf ( vHDfr _/{P$(+6148; AtC+DrG ] Uph"1 [ v!&-s!%$(+g Xv! #%J'-C03+ ; <?CU Vv! 2!$?)-/ 79R;? Sv! !$)-c/ 791;? Q!Z#&2((+),.P3w:-<>CFHe Oy D 'g)0-2Q35:@B_D M|{X!%@ -/0456G8 KWv!!%J&)X.!057D9>?B. Hv!"Q$n&(|.13 ;=?D' Fa3 m")+.2O469i; X9 &(+/03 79@BH BC8 9& @l &(r*/2x35H68=r F 7N #&(-00381;=AEG 5TL}"&+-_256;:=AzC6E 40  c _#%(-y t 0yr -eB#'}*.a26e8=T>ATCIG/ +A 'o,G-35;=BDF *D !G%$(.+/2]79:;ACF3 ("%'),/1c58n:` A &  Fx!C$&@'n,15#:<?C@F %N i #'*0@27<CpE # #'x*;-0H24N78>CFI " CA#%m)|+8-J15:? ETG/ Xz"$l +-C1%3779 q  t     ;"'), q/ r OqTVm$\ HELVETICA TIMESROMANY TIMESROMANLOGO TIMESROMANLAUREL TIMESROMAN &j/XLarkRegistrationEPROM.tioga17-Oct-83 19:52:55