Multi-Tech Systems MT9234ZPX-UPCI-NV manual Modem Cannot Connect When Dialing

Chapter 4 - Troubleshooting

The Modem Cannot Connect When Dialing

Reasons why the MultiModem may fail to connect 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

●poor line conditions.

You can narrow the list of possibilities by using extended result codes. Extended result codes are enabled by default. If they have been disabled, include V1X4 in the modem’s initialization string, or in terminal mode enter ATV1X4 and press ENTER. 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, check for a dial tone by connecting a standard telephone set to the line in place of the modem. If you hear a dial tone, your modem might be installed behind a corporate 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 with your PBX personnel or the PBX system 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. Try again later. BUSY can also indicate that you 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 using legacy software 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 HyperTerminal, select Connect from the Call menu, click Dialing Properties, and type 9 in the local and long distance boxes.

●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 there is a modem at the other end. In that case, the modems might be having problems negotiating because of incompatibilities or line noise. Try the call again, connecting at a lower speed by setting register S37 to a lower rate (for example, by typing ATS37=11 in the terminal window and pressing ENTER).

●Poor line conditions can also affect the connection. When using V.34 or V.32 client-to-client connections in poor conditions, setting S38=0 may result in better performance.

Multi-Tech Systems, Inc. MT9234ZPX User Guide 45