Specifications

 Chapter5–Troubleshooting
MT9234ZBA‐USBUserGuide 22
TheModemDoesn’tWorkwithCallerID
● CallerIDinformationistransmittedbetweenthefirstandsecondrings,soifautoansweristurnedoff(S0=0)
orifthemodemissettoanswerafteronlyonering(S0=1),themodemdoesnotreceiveCallerIDinformation.
Checkyourinitializationstring,andifnecessarychangeitto
setthemodemtoanswerafterthesecondring
(S0=2).
● MakesurethatyouhaveCallerIDservicefromyourtelephonecompany.
FaxandDataSoftwareCan’tRunattheSameTime
Onlyoneapplicationatatimecanaccesscommunicationsdevices.InWindows2003andlater,youcanhavedataandfax
communicationapplicationsopenatthesametime,buttheycannotusethesamemodematthesametime.
TheModemDialsButCannotConnect
TherecanbeseveralreasonstheZBAfailstomakeaconnection.Possibilitiesinclude:
● lackofaphysicalconnectiontothetelephoneline.
● awrongdialtone.
● abusysignal.
● awrongnumber.
● nomodemattheotherend.
● afaultymodem,computer, orsoftwareattheotherend.
● incompatibilitybetweenmodems.
Youcannarrowthelistofpossibilitiesbyusingextendedresultcodes.Extendedresultcodesareenabledby
default.Iftheyhavebeendisabled, enterATV1X4andpressEnterwhileinterminalmode,orincludeV1X4inthe
modem’sinitializationstring.Whenyoudialagain,themodemreports
thecall’sprogress.
● IfthemodemreportsNODIALTONE,checkthatthemodem’stelephonelinecableisconnectedtoboththe
modem’sLINEjack(notthePHONEjack)andthetelephonewalljack.Ifthecablelookssecure,tryreplacingit.
Ifthatdoesn’twork,theproblemmightbeinyourbuilding’stelephone
installation.Totestthebuilding
installation,plugatelephoneintoyourmodem’stelephonewalljackandlistenforadialtone.Ifyouheara
dialtone,yourmodemmightbeinstalledbehindacompanyphonesystem(PBX)withaninternaldialtone
thatsoundsdifferentfromthenormaldialtone.
Inthatcase,themodemmightnotrecognizethedialtone
andmighttreatitasanerror.CheckyourPBXmanualtoseeifyoucanchangetheinternaldialtone;if you 
can’t,changeyourmodem’sinitializationstringtoreplaceX4withX3,whichcausesthemodemto
ignoredial
tones(note,however,thatX3isnotallowedinsomecountries,suchasFranceandSpain).
● IfthemodemreportsBUSY,theothernumbermightbebusy,inwhichcaseyoushouldtryagainlater,orit
mightindicatethatyouhavefailedtoadda9,prefixtothephonenumberifyoumustdial9foranoutside
line.
● Ifyoumustdial9togetanoutsideline,theeasiestwaytodialitautomaticallyistoincludeitinthemodem’s
dialprefix,e.g.,ATDT9,.Notethecomma,whichinsertsapausebeforethenumberisdialed.Byinserting9,
intothedialprefix,youdonot
havetoincludeitineachdirectoryentry.
● TochangethedialprefixinWindows98HyperTerminal,selectCallfromtheCallmenu,clickDialing
Properties,andtype9inthelocalandlongdistanceboxesinHowIdialfromthislocation.
● IfthemodemreportsNOANSWER,theothersystemhasfailedtogooff‐hook,oryoumighthavedialeda
wrongnumber.Checkthenumber.
 