Chapter 6 – Troubleshooting
Data Is Being Lost
•If you are using data compression and a high speed serial port, set the serial port baud rate to two to six times the data rate.
•Make sure the flow control method you selected in software matches the method selected in the modem.
•Try entering the I11 command in online mode or the &V command in command mode to display information about the last connection, making a screen print of the connection statistics, and checking for parameters that might be unacceptable.
There Are Garbage Characters on the Monitor
•Your computer and the remote computer might be set to different word lengths, stop bits, or parities. If you have connected at
•You might be experiencing line noise. Enable error correction, if it is disabled, or hang up and call again; you might get a better connection the second time.
•At speeds above 2400 bps, the remote modem might not use the same transmission or error correction standards as your modem. Try connecting at a slower speed or disabling error correction. (With no error correction, however, line noise can cause garbage characters.)
•Try entering the I11 command in online mode or the &V command in command mode to display information about the last connection, making a screen print of the connection statistics, and checking for parameters that might be unacceptable.
The Modem Doesn’t Work with Caller ID
•Caller ID information is transmitted between the first and second rings, so if autoanswer is turned off (S0=0) or if the modem is set to answer after only one ring (S0=1), the modem will not receive Caller ID information. Check your initialization string, and if necessary change it to set the modem to answer after the second ring (S0=2).
•Make sure that you have Caller ID service from your telephone company.
Fax and Data Software Can’t Run at the Same Time
•Communication devices can be accessed by only one application at a time. In Windows 2000 and higher, you can have data and fax communication applications open at the same time, but they cannot use the same modem at the same time.
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