Multi-Tech Systems MT2834BA Series, MT2834BL Series manual Modem Dials But Cannot Make a Connection

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Appendix B - Troubleshooting

The Modem Dials But Cannot Make a Connection

There can be several reasons the modem 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. To enable them, enter ATV1X4 and press ENTER while in terminal mode, or include V1X4 in the modem’s initialization string. When you dial again, the modem will report 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 may 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 may 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 may not recognize the dial tone and may 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 will cause the modem to ignore dial tones.

·If the modem reports BUSY, the other number may be busy, in which case you should try again later, or it may 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 in the terminal.

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, 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.

·If the modem reports NO CARRIER, the phone was answered at the other end, but no connection was made. You might have dialed a wrong number, and a person answered instead of a computer, or you might have dialed the correct number but the other computer or software was turned off or faulty. Check the number and try again, or try calling another system to make sure your modem is working. Also, try calling the number on your telephone. If you hear harsh sounds, then another modem is answering the call, and the modems may be having problems negotiating because of modem incompatibilities or line noise. Try connecting at a lower speed.

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

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Contents User Guide User Guide Record of Revisions Date DescriptionPatents TrademarksContents Registers Index 117Introduction and Description How To Use This Manual IntroductionModem Features 1 MT2834BA/BL Series Features Fax FeaturesTechnical Specifications Power Modem LED Indicators MT2834BA LED DisplayControls on PC Board Installation and Connection What Is in Your Modem Package? InstallationSafety Warnings Installation ProcedureMultiModemBA Connections Installing PhoneTools, the Data Communications Software Is Your Modem Ready for Use?Software Configuration and Modem Basics Configuring Your Software Configuring Software for Your ModemSoftware Configuration PC Initialization StringsChanging Default Parameters Configuring Software for Your ComputerOther Parameters AT &F S0=0 &F9 &W0 CRAnswer/Originate Voice/Data Toggle Switch Modem BasicsSimple Operations Manual Dial and Automatic Answer Dialing/On-Line/Answering Manual Dial and Automatic AnswerManual Dial Backup Call Termination Dial Backup and Leased Line RestoralAutomatic Leased Line Restoral Operation Dial-Up Operation Manual Call OriginationAutomatic Answering Manual AnsweringAbort Timer Handshaking DetailsCall Termination Command Mode AT Command Editing Command ModeFunctional Modes Summary of AT Commands Functional ModesStore Modem Configure Data Result Codes Multi-Tech Result CodesStandard AT Result Codes Dialing Commands Dialing Action CommandsDial Modifier Commands Voice/Data Dialing $VDPulse or Tone Dial P T Set Pulse Dial Ratios &PReturn to Command Mode After Dial Command Execution Reverse the Mode of Operation RAutomatic Pauses in Dialing Long Space Disconnect YCalling Card Detect Tones $ Quiet Answer @Phone Number Memory Commands Storing Phone Numbers D...NNumber Linking NN Listing Numbers Stored in Memory LConfiguration and Default Storage Commands Loading Factory Defaults &FModem Reset Z Async/Sync Mode Switching &M Unix Uucp Spoofing $SPSynchronous Transmit Clock Select &X Command Response Result Code Commands Echo Command Mode Characters EResult Codes Enable/Disable and No Response Answer Q Result Codes Multi-Tech or Standard AT &QResult Codes Basic and Extended and Call Progress Selection Phone Line Conditioning Commands Enable/Disable Trelis Coded Modulation #TGuard Tones Not Used in BAI/BLI Models &G Bell/V.21 ToneFallback Modes When On-Line #F Enable/Disable Lowspeed Fast Connect $FCCleardown at Disconnect &CD Auto Speed Detect #A7 RS-232C Interface Control Commands Carrier Detect Control &CData Terminal Ready Control &D CTS Control &RData Set Ready Control &S CTS/RTS Interaction Control &RFDSR/CD Interaction Control &SF Error Correction Commands Normal Mode &E0Auto-Reliable Mode &E1 Reliable Mode &E2Mode Select #L Auto-Reliable Buffering $AEnable/Disable Auto Reliable Fallback Character $F Error Correction/300bps $ERetransmit Count $R Flow Control Commands Hardware Flow Control &E4Xon/Xoff Flow Control &E5 Xon/Xoff Pass-Through &E7 Send Xon/Xoff Characters #XHewlett-Packard ENQ/ACK Pacing &E9 Normal Mode Modem Flow Control On &E11 Terminal/Computer Initiated Pacing &E13Maximum Block Size &BS Parity Selection #PNormal/Auto-Reliable/Reliable Mode Commands Xon/Xoff Pass-Through CommandsEnq/Ack Pacing Commands Speed Conversion Commands Speed Conversion $BAModem Baud Rate $MB Serial Port Baud Rate $SB Immediate Action Commands Listing On-Line Diagnostics L8 Off Hook HLine Probe Commands Force Answer Mode aExiting Command Mode, Going Back On-Line O Registers Number of Rings Until Modem Answers Rings Which Have OccurredEscape Code Character Return CharacterTime for Carrier Abort Timer Line Feed CharacterBackspace Character Wait Time for Dial ToneS10 Carrier Loss Disconnect Delay Time S13 Remote Configuration Escape CharacterCarrier Detect Response Time S11 Tone Dialing Tone Spacing and DurationS15 Callback Time Delay S19 MT2834BL Only Dial-Back TimerS16 Callback Attempts S17 Changing Break TimeS26 Failed Password Attempts S29 Local Inactivity TimerS24 PBX/CBX Disconnect Drop Time for DSR/CTS/CD S25 DTR Dropout TimeS30 Inactivity Timer S32 Time Elapse for Escape SequenceS36 Time Between DTR Inactive and Modem Off-Hook S37 Time Between DTR Active and Modem On-HookS48 Program V.34bis Connect Speeds Reading and Assigning S-Register Values Examples of Assigning ValuesExamples of Reading Values AT Command and S-Register Summary Callback Security and Remote Configuration Callback Feature Description Callback Security and Remote ConfigurationRemote Configuration Description To change your Remote Configuration feature statusTo set parity of the password/message prompt AT#CBN0xxxxxxxxxxCRCallback Operational Sequence Procedures Remote Configuration Procedures Remote Configuration Operation ProceduresRemote Configuration and Callback Security AT Commands Remote Configuration/Callback Security S-Registers DIP-Switch Settings Dip-Switch Settings MT2834BA PC BoardDIP-Switch Option Settings Switch #4 AS/400 Mode Synchronous Mode/Leased Line/Dial-UP = Down Down Dip-Switch Settings Speaker Volume Control Recording Option Configurations Switch Function Position EffectDIP Switches #13-14 DIP Switches #15-16 MT2834BADIP Switches #15-16 MT2834BL Warranty, Service and Tech Support Multi-Tech Systems, Inc. Warranty & Repairs Policies Warranty, Service, and Technical SupportOnline Warranty Registration Repair Procedures for International DistributorsReplacement Parts Technical SupportInternet Sites Country TelephoneAppendixes Upgrade Overview Appendix a Upgrading Your Modem’s FirmwareAppendix a Upgrading Your Modem’s Firmware Download the Upgrade File Upgrade the Modem’s Firmware Appendix B Troubleshooting None of the LEDs Light When the Modem Is OnModem Does Not Respond to Commands Appendix B TroubleshootingAppendix B Troubleshooting Modem Dials But Cannot Make a Connection Modem Cannot Connect When Answering Modem Disconnects While On-lineFile 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 DsNd Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 100$FCn MT2834BL Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 101$MBn Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 102$SBn Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 103Dial Tone Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 104Callback Security/Remote Configuration Command Summary Password Command Summary 25bis CommandsDelayed and Forbidden Numbers Appendix D V.25bis Operation25bis Operation Appendix D V.25bis Operation25bis Mode AT Commands 25bis DIP-Switches25bis Set-Up and Initialization Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 10825bis AT Commands Enable/Disable V.25bis Mode $V CommandChange Serial Baud Rate CSP Command 25bis Responses Result CodesDial Phone Number Provided CRN Command Listing Delayed Phone Numbers RLD CommandListing Forbidden Phone Number RLF Command Disregard or Connect to Incoming Calls DIC or CIC CommandITU V.25bis Country Specific Information Appendix D V.25bis Operation Belgium SingaporeMulti-Tech Systems, Inc. MT2834BA/BL Series User Guide 112 Appendix E MultiModemBA Cables Appendix E MultiModemBA/BL CablesAppendix F Regulatory Information FCC Part 68 TelecomFCC Part Canadian Limitations Notice Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 115South African Notice Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 116Appendix G Weee Statement Index Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 11791-116 Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 118PBX/CBX Disconnect Drop Time for DSR/CTS/CD63 Multi-Tech Systems, Inc. MT2834BA/BL Series User Guide 119