Multi-Tech Systems MT4X56USB manual Modem Disconnects While Online, Troubleshooting

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Chapter 6 - Troubleshooting

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 will report the call’s progress.

If the modem reports NO DIALTONE, check that the modem’s phone cable is securely 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 find out, plug a telephone into your modem’s wall jack and listen for a dial tone. If you hear a one, your modem might be installed behind a company phone system (PBX) with an internal dial tone that sounds different from the normal one. 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 will cause 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.

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 might be having problems negotiating because of modem incompatibilities or line noise. Try connecting at a lower speed.

The Modem Disconnects While Online

If you have Call Waiting on the same phone line as your modem, it can interrupt your connection when someone tries to call you. If you have Call Waiting, disable it before each call. In most telephone areas in North America, 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 98 HyperTerminal, select Call from the Call menu, click Dialing Properties, check This location has Call Waiting, and select the correct code for your phone service.

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Contents User Guide MultiModemUSB Model MT4X56USBTrademarks User GuideRecord of Revisions PatentsContents Glossary of Terms Index Introduction and Description MultiModemUSB User Guide FeaturesIntroduction Introduction and Description Technical SpecificationsInstallation Preview of this GuideRelated Documentation System Front PanelModem Ports Ports 1, 2, 3, HubPower Connector RJ-ll Modem ConnectorUSB Type a Upstream Connector USB Type B Downstream ConnectorInstallation Unpacking Safety Warning TelecomCabling your MT4X56USB InstallationMT4X56USB Software Loading and Configuration MT4X56USB Drivers for Windows System USB SupportLoading your Driver Software Software Loading and Configuration Uninstalling MultiModemUSB in Windows MT4X56USB Drivers for Windows Uninstalling MultiModemUSB in Windows MT4X56USB Drivers for Windows NT MultiModemUSB Drivers Install dialog box displays Click NextAdd/Remove Uninstalling MultiModemUSB in Windows NTSelect Add/Remove Programs MT4X56USB Drivers for Windows Click Finish Software Loading and Configuration Select Add/Remove Hardware Click Start Settings Control Panel Modems Installing Your V.90 ModemsRead Carefully Software Loading and Configuration MT4X56USB Click Start Settings Control Panel Phone and Modems option Installing Your V.90 Modems WindowsMT4X56USB Software Loading and Configuration Windows 95/98 Configuration Utility MT4X56USB Windows NT 4.0/2000 Configuration Utility MT4X56USB MT4X56USB AT Commands, S-Registers and Result Codes Answer AT Command SummaryCommand Enter Key Repeat Last CommandAT Commands, S-Registers and Result Codes Modulation Handshake Return Online to Data ModeResult Codes Enable/Disable Information RequestResult Code Format Modem ResetLoad Factory Settings Tone DialingDisplay Current Settings Communications ModeAsynchronous Communications Mode Test Commands\An Select Maximum MNP Block Size Store Current ConfigurationSelect Stored Configuration for Hard Reset Command &Zy=x Store Dialing Command\Qn Flow Control Selection \Nn Error Correction Mode Selection\Tn Inactivity Timer \Kn Break ControlCommand #S=x Store Setup Password Command %DCn AT Command ControlCommand %En Fallback and Fall Forward Control Enter Setup PasswordCommand %%%ATCRRemote Configuration Escape Sequence Command +++ATCR Escape SequenceRegisters Register Unit Range Default DescriptionUpstream data rates S38Terse Verbose Description Result CodesFor more information on scripting, click the Help button Remote Configuration Changing the Setup Password Remote Configuration ProcedureSetup Changing the Remote Escape Character Remote Configuration CommandsRemote Configuration and Management MT4X56USB Troubleshooting Modem Dials But Cannot Connect None of the Indicators LightModem Does Not Respond to Commands Modem Disconnects While Online TroubleshootingFax and Data Software Can’t Run at the Same Time Modem Cannot Connect When AnsweringLoopback Tests Modem Doesn’t Work with Caller IDLocal Analog Loopback Test V.54 Loop Test procedureRemote digital loopback test Remote Digital Loopback Test V.54 LoopLocal digital loopback test Local Digital Loopback Test V.54 LoopDouble-click the Universal Serial Bus Controller icon Windows 95/98 TroubleshootingDetermining Why USB Support Is Not Present Installing Microsoft USB SupportUpgrade Procedure Multi-Tech Web Site Upgrade OverviewIdentify the MT4X56USB Firmware Identify the Current Firmware VersionClear Your Stored Paramenters Download the Upgrade FileExtract the Upgrade Files Upgrade ProcedureRestore Your Parameters Upgrade the Modem’s FirmwareService, Warranty and Tech Support Software User License Agreement Tech Support Limited WarrantyOn-line Warranty Registration Service, Warranty and Tech SupportContacting Tech Support via E-mail ServiceAppendices Industry Canada Appendix a Regulatory InformationClass B Statement FCC PartAppendices FCC Part 68 TelecomCanadian Limitations Notice FAX Branding StatementInternational Modem Restrictions EMC, Safety and Terminal Directive ComplianceCommission Decision CTR21 New Zealand Telecom Warning NoticeIntroduction TroubleshootingAppendix B V.90 Support Glossary of Terms MT4X56USB Glossary MT4X56USB Glossary MT4X56USB Glossary MT4X56USB Glossary MT4X56USB Glossary MT4X56USB Glossary MT4X56USB Index IndexConfiguration MT4X56USB Software user license agreement Speed