Multi Tech Equipment manual MTA128ST/NT dials but cannot make a connection

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Troubleshooting

you should change their IRQs to unused ones, if possible.

Right-click on My Computer, select Properties from the menu, click on the Device Manager tab, double-click on Ports, then double-click on the Communications Port your MTA1 28ST/NT is connected to. In the port’s Properties sheet, click on the Resources tab to see the port’s Input/Output range and Interrupt Request. If another device is using the same address range or IRQ, it will appear in the Conflicting Device List. Uncheck Use Automatic Settings to change the port’s settings so they do not conflict with the other device, or select the port the conflicting device is on and change it instead. If you need to open your computer to change switches or jumpers on the conflicting device, refer to the device’s documentation.

•The serial port may be defective. If you have another serial port, install the MTA1 28ST/NT on it, change the COM port setting in your software, and try again.

•If using serial rates above 115,200 baud, make sure the serial port can handle higher rates. Most standard serial ports have a maximum serial rate of 115,200. To handle serial rates of 230,400 baud and 460,800 baud, you need a high-speed serial port Even though some terminal emulation programs allow you to select higher rates, the serial ports cannot always handle those rates.

•The MTA1 28ST/NT may be defective. If you have another Multi-Tech MTA1 28ST/NT, try swapping MTA1 28ST/NTs. If the problem goes away, the first MTA1 28ST/NT is possibly defective. Call Tech Support for assistance (see Chapter 7).

The MTA128ST/NT dials but cannot make a connection

There can be several reasons the MTA128ST/NT fails to make a connection. Possibilities include

•Lack of a proper physical connection to the communication line.

•A busy signal.

•Awrong number.

•No terminal adapter at the other end.

•A faulty communications device, computer, or software at the other end.

•Incompatibility between communications devices.

•An improperly configured MTA128ST/NT.

Narrow the list of possibilities by using extended result codes. To enable them, enter ATV1X2 and press ENTER while in terminal mode or include V1X2 in the MTA128ST/NT’s initialization string (V1X2 is enabled by default). When you dial again, the MTA128ST/NT reports the call’s progress.

•If the MTA128ST/NT reports NO DIALTONE, check that the ISDN S/T cable is securely connected to both the TA’s ISDN jack (not the PHONE jack) and the ISDN network terminator or 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. Make sure ISDN cables on all devices are wired straight-through (pin 1 to pin 1, pin 2 to pin 2, etc.) and do not have reversed pairs. The cable must have at least the middle four pins (pins 3, 4, 5, and 6) connected. A reversed pair on the U (phone company) side is not important, but a reversed pair on the S/T (your) side can create problems if you have more than one device, since multiple devices attached to the S/T interface must all have the same polarity.

•If the MTA1 28ST/NT reports BUSY, the other number may be busy, in which case you should try again later.

•If the MTA1 28ST/NT reports NO CARRIER, no connection was made. 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 TA is working. Also, check that you accurately configured the TA with the correct switch type, TEIs, data protocols, and other parameters needed for a successful call (see Chapter 3).

You can place data calls but not voice calls or vice versa

•You might not have ordered both voice and data service from your ISDN provider. Check your contract or latest statement of service from your ISDN provider.

•Your ISDN provider may have programmed the switch incorrectly. Call the provider.

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Contents Page Trademarks Model MTA128ST/NT S000305C Rev. CRevision Date Description Contents Product Description Introduction and DescriptionNT1 Connection FeaturesSpid Service Profile ID Isdn BRI LinePin Pin TE SignalInterlace LED Indicators LED P1 LED P2 LED Connectors Switch CompatibiltiyLED Indicators Command InterfaceConnecting your TA Hardware InstallationSafety Warnings Connect the TA to Your PC RS-232 Connection Before You Start Configuration UtilitiesNetwork Configuration IntroductionVoice TEI Call Control ConfigurationDialing Numbers COM Port SettingsDCD Drop Time Configuring your TA Page Page Page Page Page Page Page Page AT Commands MTA128S T/NT Commands and S-RegistersAT Commands by Function Register Summary Digital Data Call Commands aAnalog Pots Call Commands RegistersAT Commands, S-Registers, and Result Codes Result Codes Using AT Commands to Operate the MTA128ST/NTAnswering a Call Making a CallAnswering Automatically Hanging UpAnswering Manually Introduction Troubleshooting the TASpecific Troubleshooting Situations Troubleshoot ingDebugging/Logging/Troubleshooting Command Summary AT Debugging/Logging/Troubleshooting CommandsDebugging/Logging/Troubleshooting S-Registers None of the LEDs light when the MTA128ST/NTis onMTA128ST/NT does not respond to commands You can place data calls but not voice calls or vice versa MTA128ST/NT dials but cannot make a connectionFile transfer appears slower than it should be MTA128ST/NT cannot connect when answeringYou cannot place two simultaneous data calls MTA128ST/NT disconnects while onlineApple Macintosh Compatibility Dynamic Bandwidth Allocation DBA Bonding Using the &, I and + CharactersMaking PPP/MLPPP Connections Software Applications that can Format PPP DataDBA Data Protocols DBA Features Bandwidth-on-Demand BOD-S60, S61, S62, and S63PPP/MLPPP Repair Procedures for U.S. and Canadian Customers Warranty, Service, and Tech SupportWarranty Repair Procedures for International Distributors Replacement PartsQuick Setup Example AppendixAConfiguration ProfilesQuick Setup Factory Profiles Loop Qualification Bearer ServiceAppendix B Ordering Your Isdn Li ne Using Isdn Ordering Codes IOCs M5 previously Generic Data M-1DN J3 previously Generic Data J-1DNCapability S previously Generic Data M Ordering Isdn Without IOCs Appendices Appendices FCC AppendixC FCCand Canadian RegulationCanadian Limitations Notice Using AT Commands to Configure the MTA128ST/NT AppendixD Configuration MethodsFirmware-based Configuration Utility Configuration via AT CommandsGlossary SymbolGlossary IETFInternet Engineering Task Force PPPMultilink Protocol or MP-is an Internet Glossary TA-Seeterminal adapter Information pages from a central resource. See also Isdn Canadian Regulation 56 Appendix IndexUart
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