Multi-Tech Systems MT2834BA Modem Disconnects While On-line, Modem Cannot Connect When Answering

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Appendix B - Troubleshooting

The Modem Disconnects While On-line

·If you have call waiting on the same phone line as your modem, it may interrupt your connection when someone tries to call you. If you have call waiting, disable it before each call. In most telephone areas, you can disable call waiting by preceding the telephone number with *70 (check with your local telephone company).

You can automatically disable call waiting by including the disabling code in the modem’s dial prefix (e.g., ATDT*70,—note the comma, which inserts a pause before the number is dialed). To change the dial prefix in Windows Terminal, select Settings, Modem Commands. To change it in Windows 95 HyperTerminal, select Call, Connect from the menu bar, click Dialing Properties, check this location has Call Waiting, and select the correct code for your phone service.

·If you have extension phones on the same line as your modem, you or someone else can interrupt the connection by picking up another phone. If this is a frequent problem, disconnect the extension phones before using the modem, or install another phone line especially for the modem.

·Check for loose connections between the modem and the computer, the telephone jack, and AC power.

The Modem Cannot Connect When Answering

·Auto-answer may be disabled. Turn on auto-answer in your datacomm program or send the command ATS0=1 to your modem in terminal mode.

File Transfer Is Slower Than It Should Be

·Is your line noisy? If there is static on your line, the modem has to re-send many blocks of data to insure accuracy. You must have a clean line for maximum speed.

·Are you downloading a compressed file with MNP 5 hardware compression enabled? Since hardware data compression cannot compress a file already compressed by an archiving program, the transfer can be marginally slower with data compression enabled than with it disabled.

·Try entering the L8 (List Online Diagnostics) command in on-line mode, making a screen print of the diagnostics listing, and checking for parameters that may be unacceptable (number of retrains, round trip delay, etc.).

I Am Losing Data

·If you are using data compression and a high speed serial port, set the serial port baud rate to four times the data rate.

·Make sure the flow control method you selected in software matches the method selected in the modem.

·Try entering the L8 (List Online Diagnostics) command in on-line mode, making a screen print of the diagnostics listing, and checking for parameters that may be unacceptable (number of retrains, round trip delay, etc.).

Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide

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Contents User Guide Record of Revisions Date Description User GuidePatents TrademarksContents Index 117 RegistersIntroduction and Description Introduction How To Use This ManualModem Features Fax Features 1 MT2834BA/BL Series FeaturesTechnical Specifications Power MT2834BA LED Display Modem LED IndicatorsControls on PC Board Installation and Connection Installation What Is in Your Modem Package?Safety Warnings Installation ProcedureMultiModemBA Connections Is Your Modem Ready for Use? Installing PhoneTools, the Data Communications SoftwareSoftware Configuration and Modem Basics Configuring Software for Your Modem Configuring Your SoftwareSoftware Configuration PC Initialization StringsConfiguring Software for Your Computer Changing Default ParametersOther Parameters AT &F S0=0 &F9 &W0 CRModem Basics Answer/Originate Voice/Data Toggle SwitchSimple Operations Manual Dial and Automatic Answer Manual Dial and Automatic Answer Dialing/On-Line/AnsweringDial Backup and Leased Line Restoral Manual Dial Backup Call TerminationAutomatic Leased Line Restoral Operation Manual Call Origination Dial-Up OperationManual Answering Automatic AnsweringHandshaking Details Abort TimerCall Termination Command Mode Command Mode AT Command EditingFunctional Modes Functional Modes Summary of AT CommandsStore Modem Configure Data Multi-Tech Result Codes Result CodesStandard AT Result Codes Dialing Action Commands Dialing CommandsVoice/Data Dialing $VD Dial Modifier CommandsPulse or Tone Dial P T Set Pulse Dial Ratios &PReverse the Mode of Operation R Return to Command Mode After Dial Command ExecutionAutomatic Pauses in Dialing Long Space Disconnect YQuiet Answer @ Calling Card Detect Tones $Storing Phone Numbers D...N Phone Number Memory CommandsNumber Linking NN Listing Numbers Stored in Memory LLoading Factory Defaults &F Configuration and Default Storage CommandsModem Reset Z Unix Uucp Spoofing $SP Async/Sync Mode Switching &MSynchronous Transmit Clock Select &X Echo Command Mode Characters E Command Response Result Code CommandsResult Codes Enable/Disable and No Response Answer Q Result Codes Multi-Tech or Standard AT &QResult Codes Basic and Extended and Call Progress Selection Enable/Disable Trelis Coded Modulation #T Phone Line Conditioning CommandsGuard Tones Not Used in BAI/BLI Models &G Bell/V.21 ToneEnable/Disable Lowspeed Fast Connect $FC Fallback Modes When On-Line #FCleardown at Disconnect &CD Auto Speed Detect #ACarrier Detect Control &C 7 RS-232C Interface Control CommandsData Terminal Ready Control &D CTS Control &RCTS/RTS Interaction Control &RF Data Set Ready Control &SDSR/CD Interaction Control &SF Normal Mode &E0 Error Correction CommandsAuto-Reliable Mode &E1 Reliable Mode &E2Auto-Reliable Buffering $A Mode Select #LError Correction/300bps $E Enable/Disable Auto Reliable Fallback Character $FRetransmit Count $R Hardware Flow Control &E4 Flow Control CommandsXon/Xoff Flow Control &E5 Send Xon/Xoff Characters #X Xon/Xoff Pass-Through &E7Hewlett-Packard ENQ/ACK Pacing &E9 Terminal/Computer Initiated Pacing &E13 Normal Mode Modem Flow Control On &E11Maximum Block Size &BS Parity Selection #PXon/Xoff Pass-Through Commands Normal/Auto-Reliable/Reliable Mode CommandsEnq/Ack Pacing Commands Speed Conversion $BA Speed Conversion CommandsModem Baud Rate $MB Serial Port Baud Rate $SB Immediate Action Commands Off Hook H Listing On-Line Diagnostics L8Force Answer Mode a Line Probe CommandsExiting Command Mode, Going Back On-Line O Registers Rings Which Have Occurred Number of Rings Until Modem AnswersEscape Code Character Return CharacterLine Feed Character Time for Carrier Abort TimerBackspace Character Wait Time for Dial ToneS13 Remote Configuration Escape Character S10 Carrier Loss Disconnect Delay TimeCarrier Detect Response Time S11 Tone Dialing Tone Spacing and DurationS19 MT2834BL Only Dial-Back Timer S15 Callback Time DelayS16 Callback Attempts S17 Changing Break TimeS29 Local Inactivity Timer S26 Failed Password AttemptsS24 PBX/CBX Disconnect Drop Time for DSR/CTS/CD S25 DTR Dropout TimeS32 Time Elapse for Escape Sequence S30 Inactivity TimerS36 Time Between DTR Inactive and Modem Off-Hook S37 Time Between DTR Active and Modem On-HookS48 Program V.34bis Connect Speeds Examples of Assigning Values Reading and Assigning S-Register ValuesExamples of Reading Values AT Command and S-Register Summary Callback Security and Remote Configuration Callback Security and Remote Configuration Callback Feature DescriptionTo change your Remote Configuration feature status Remote Configuration DescriptionAT#CBN0xxxxxxxxxxCR To set parity of the password/message promptCallback Operational Sequence Procedures Remote Configuration Operation Procedures Remote Configuration ProceduresRemote Configuration and Callback Security AT Commands Remote Configuration/Callback Security S-Registers DIP-Switch Settings MT2834BA PC Board Dip-Switch SettingsDIP-Switch Option Settings Switch #4 AS/400 Mode Synchronous Mode/Leased Line/Dial-UP = Down Down Dip-Switch Settings Speaker Volume Control Switch Function Position Effect Recording Option ConfigurationsDIP Switches #15-16 MT2834BA DIP Switches #13-14DIP Switches #15-16 MT2834BL Warranty, Service and Tech Support Warranty, Service, and Technical Support Multi-Tech Systems, Inc. Warranty & Repairs PoliciesRepair Procedures for International Distributors Online Warranty RegistrationTechnical Support Replacement PartsInternet Sites Country TelephoneAppendixes Appendix a Upgrading Your Modem’s Firmware Upgrade OverviewAppendix a Upgrading Your Modem’s Firmware Download the Upgrade File Upgrade the Modem’s Firmware None of the LEDs Light When the Modem Is On Appendix B TroubleshootingModem Does Not Respond to Commands Appendix B TroubleshootingAppendix B Troubleshooting Modem Dials But Cannot Make a Connection Modem Disconnects While On-line Modem Cannot Connect When AnsweringFile Transfer Is Slower Than It Should Be Am Losing DataAm Getting Garbage Characters on the Monitor Appendix C AT Command Summary Appendix C AT Command SummaryCommand Values Description Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 100 DsNdMulti-Tech Systems, Inc. MT2834BA/BL Series User Guide 101 $FCn MT2834BLMulti-Tech Systems, Inc. MT2834BA/BL Series User Guide 102 $MBnMulti-Tech Systems, Inc. MT2834BA/BL Series User Guide 103 $SBnMulti-Tech Systems, Inc. MT2834BA/BL Series User Guide 104 Dial ToneCallback Security/Remote Configuration Command Summary 25bis Commands Password Command SummaryAppendix D V.25bis Operation Delayed and Forbidden Numbers25bis Operation Appendix D V.25bis Operation25bis DIP-Switches 25bis Mode AT Commands25bis Set-Up and Initialization Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 108Enable/Disable V.25bis Mode $V Command 25bis AT CommandsChange Serial Baud Rate CSP Command 25bis Responses Result CodesListing Delayed Phone Numbers RLD Command Dial Phone Number Provided CRN CommandListing Forbidden Phone Number RLF Command Disregard or Connect to Incoming Calls DIC or CIC CommandITU V.25bis Country Specific Information Singapore Appendix D V.25bis Operation BelgiumMulti-Tech Systems, Inc. MT2834BA/BL Series User Guide 112 Appendix E MultiModemBA/BL Cables Appendix E MultiModemBA CablesFCC Part 68 Telecom Appendix F Regulatory InformationFCC Part Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 115 Canadian Limitations NoticeMulti-Tech Systems, Inc. MT2834BA/BL Series User Guide 116 South African NoticeMulti-Tech Systems, Inc. MT2834BA/BL Series User Guide 117 IndexMulti-Tech Systems, Inc. MT2834BA/BL Series User Guide 118 91-116Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 119 PBX/CBX Disconnect Drop Time for DSR/CTS/CD63