If your faxmodem is not working please read your communications software documentation carefully. Then return to this chapter.

This chapter covers four categories:

• general troubleshooting
• echo troubleshooting
• dial troubleshooting
• and online troubleshooting

• Make sure the faxmodem is inserted securely in the PC card slot.

• Your faxmodem may have not been initialized. Exit and restart your communications software application.

• The most common error with faxmodems is that more than one piece of hardware is assigned to the same COM port, or that the software is not configured for the same COM port as the faxmodem. For example, if the faxmodem is configured for COM2, the software should be configured for COM2. Your card management software should make sure that no other device installed in your computer is trying to use the same COM port setting as the faxmodem. You can check that you have used the correct COM port setting in your software.

• Note that if your computer has an external serial port, it can create a conflict, even if you are not using the port. This holds true for serial ports on cards, peripheral devices, and built-in serial ports. Some trackball pointing devices are assigned to a serial port. In general, when a PC has one built-in serial port, the port is assigned to COM1. If you don’t know which COM port to use, try configuring your faxmodem for COM2; then be sure to configure your data communications and fax software to match.

• Your faxmodem may not be receiving the required initialization string from your software. Exit and reenter your software program.

• Your computer may be in sleep mode. In addition to enabling auto-answer in your fax or data communications software, you should disable sleep mode in your computer. See the computer’s documentation for instructions.

• Your faxmodem may not be configured to automatically answer incoming calls. Select auto-answer in your software. If your software does not have an auto-answer option, you can set auto-answer in terminal mode. Change to terminal mode, type AT SO=n and press the Enter key, where n is the number of rings that you want to occur before the faxmodem auto-answers calls.

• The faxmodem is configured for auto-answer. Turn off (cancel) the auto-answer option in your software. If you are using terminal mode, type AT SO=O and press the Enter key to turn off auto-answering.

• Check that your communications software has been set up properly. Recheck the initialization string and dial string specified in your software manual. Remember that commands in the initialization string are sent to the faxmodem each time you start your software and override the settings stored in the faxmodem’s non-volatile memory.

• On IBM PC-compatible computers, memory-resident (TSR) programs can cause a variety of problems for some fax software programs. Try starting up your computer without them.

• If your software requires that DCD always be forced ON (which is the faxmodem’s default setting, but not common in software), and you are using the &C1 command in the faxmodem initialization string or have stored it in non-volatile memory, your faxmodem will not work properly. If this is the case, store the &CO command in nonvolatile memory: Type AT &CO BWO IYO and press the Enter key.

• Be sure you type AT at the beginning of the command line.

• Be sure your faxmodem is not in data mode when you type the command. Use the escape character sequence (default is + + +) to switch to command mode.

• Make sure the communications software is configured for the same COM port as your faxmodem. If the faxmodem is configured for COM2, the software should be configured for COM2.

If you typed a command but did not receive an OK response from your faxmodem:

• The EO and Q1 commands may be in effect, disabling echo and responses. To verify this in terminal mode, type AT &V and press the Enter Key. To enable echo and responses in terminal mode, type AT El QO and press the Enter key.

• Your faxmodem may have been in data mode (online) when you typed the command. The faxmodem does not respond to AT commands while in data mode. To change to terminal mode while still in data mode, type + + + and pause for a second. To return to data mode, type AT O and press the Enter key.

• Check whether you typed an unacceptable command.

• Be sure your command line contains fewer than 40 characters.

The speaker volume is too low or too high.

• The PCMCIA faxmodem does not have a built-in speaker. However, you can use the speaker control settings in your software to turn the computer’s speaker on or off, or to increase or reduce the speaker volume. If your software does not handle speaker settings you can add one each of the following AT Mn and AT Ln commands to the faxmodem initialization string in the software.

Speaker Control

MO Turns off the speaker
M1 (factory setting) Turns on the sneaker until the faxmodem detects carrier
M2 Speaker always on
M3 Speaker on after dialing until carrier detected Speaker Volume
LO Lowest volume
L1 (factory setting) Low volume
L2 Medium volume
L3 High volume

Note that the PCMCIA standard digital signaling from the faxmodem to the computer speaker produces inherently low fidelity sound. You may not notice a difference in volume between medium (L2) and high (L3).

• Your communications software has its echo feature turned on and the faxmodem’s echo feature is also turned on.

• If the remote system echoes your typed characters, change to terminal mode and type AT El and press the Enter key. Then turn off your communication software’s local echo. Your faxmodem will echo commands during command mode and the remote system will echo your typing during data mode.

• If the remote system does not echo your typed characters, change to terminal mode and type AT EO and press the Enter key. Then turn on your communication software’s local echo. Your software will echo commands during terminal mode and any typing performed during data mode.

• When you make a connection with a remote system and exchange data, the data will appear on your screen if you are in full-duplex operation. If you do not see the data, be sure the computer you are communicating with is operating full-duplex. Another cause may be that the remote system is waiting to receive your data before echoing it back to your system.

• If neither of these is the cause, other software on your computer may be affecting communications.

• If you can’t see the characters you are typing, change to terminal mode type ATE1 and press the Enter key.

• Make sure that you are dialing a valid phone number, including any required dial prefixes.

• If you are using touchtone dialing on a line that requires pulse dialing, the line may not be able to accept touchtone-dialed calls. Change the software dialing prefix to ATDP to specify pulse dialing.

The faxmodem does not respond to Dial commands from your software.

• Make sure software dialing prefix is ATDT, if tone dialing is provided by the telephone service.

• Make sure your communications software, card management software, and faxmodem are configured for the same COM port.
  
• Make sure your faxmodem has hung up from the previous call. Change to AT command mode, wait one second, type ATH and press the Enter key to hang up the faxmodem.

• Your faxmodem negotiates the highest mutually compatible connection with a remote modem. However, when you are calling a remote modem that does not support data compression or error correction, this negotiation process may take too long or may result in incomprehensible characters reaching your faxmodem or the remote modem, causing one of them to break the connection. You may be able to solve this problem using an AT command string to disable the speed or protocol negotiation process or both. Refer to the table on the next page. Enter the command before you make the call or include the command string in the dial prefix for calling a particular modem.

• If a remote modem does not respond because of the extended negotiation process, you may have to disable part or all of the negotiation process. In the table on the next page, "protocol" means error correction and data compression. Note that the first two lines in the table are likely to be the most valuable.

There are other configurations that can be forced, as well. If you need to select a particular configuration, use the AT command strings shown below. You can always return to the faxmodem’s factory default configuration by changing to terminal mode, typing AT&F and pressing the Enter key. But remember that if you do that, the faxmodem will not have received the commands in your software’s initialization string, as it normally would. Using the ATZ command overcomes this problem if you have saved all of your setup parameters in non-volatile memory. (To save setup parameters in non-volatile memory in terminal mode: Type AT, followed by the parameter settings you choose, followed by &WO or &W1, and press the Enter key. For example, if you type AT &C1 &D2 &WO and press the Enter key, the &C1 and &D2 parameter settings are stored in Profile O. See Appendix B for the table of AT commands.)

• Many bulletin boards and other services will adjust to the speed of the calling modem.

• Telephone lines in some areas may not support reliable operation at 2400 bps or higher.

• Be sure the remote computer is operating full-duplex.

• The remote system is waiting to receive your data before echoing it back to your system. Try pressing the Enter key several times.

• Other software or hardware on your computer is affecting communications.

• If you are using software, make sure the speaker is enabled in the software.

• If you are using software, make sure the speaker is enabled. If your software has no means for selecting the speaker, add M1 U to the faxmodem initialization string.

• The remote system has hung up.

• The telephone service disrupted or disconnected your call. O Your computer or terminal (DTE) has turned off the Data Terminal Ready (DTR) signal to your faxmodem. Try the call again. If the problem persists, replace &D2 in the faxmodem initialization string with &DO. Exit and restart your software so that the faxmodem receives the new initialization string. TIy the call again.

• If your faxmodem places calls but never makes a connection and if you don’t hear the high-pitched tone when the remote side answers, there may be a problem at the remote location. If possible, make a voice call to the other party and discuss the problem with them.

• The telephone service disrupted or disconnected your call.

• The connection may have been established on poor-quality or noisy telephone lines. Disconnect and place the call again to try and obtain a better connection.

• Someone may be picking up an extension connected to the line that your faxmodem is using. If the faxmodem is sharing a telephone line with other telephones, inform the other users when you will be making a data call.

• Your telephone line may have a Call Waiting feature and a call is being received. You may be able to disable Call Waiting by adding the prefix *70, for tone dialing (1170 for pulse dialing) to the telephone number when you dial from the software. For more information refer to the section "Customizing FaxModem Settings" in Chapter 2.

• Use the MNP or V.42 protocol if the remote modem supports one of these protocols.

• Reduce the baud rate.

• If both modems or faxmodems are using the MNP or V.42 protocol, the only way this can occur is if your faxmodem and communications software are not using the appropriate flow control. Configure your communications software for Hardware (RTS/CTS) now control. This allows your computer to pause for the transmission to be stored.

• Your communications software character setup (start bit, data bits, stop bits, and parity bit) does not match that of the remote system. Check your settings against those used by the remote system and make sure they match. Pay particular attention to the parity setting, as this is the most common difference among systems. You should normally use 8 data bits, NO parity, and 1 stop bit (8, NONE, 1). The second most common setting is 7 data bits, EVEN parity, and 1 stop bit (7, EVEN, 1).

• Your software needs to use a streaming protocol, such as Ymodem-G or Zmodem. Xmodem and Ymodem are not adequate.

• Your software must be set up so that your faxmodem is using hardware flow control (RTS/CTS ON).

• You may use a computer-to-faxmodem speed of 57,600 bps; set this for each entry in the dialing directory.

• Be aware that many bulletin boards download files that have already been compressed. In general, your faxmodem will not be able to further compress such files.