52
or
Your computer’s serial port is not working properly. Contact your local computer dealer for
assistance.
or
You have selected hardware or software flow control on the modem (using
AT&K3
or
AT&K4
),
but not in your software. Both your hardware and software must be set to use the same type of flow
control. If your software does not allow you turn flow control on and off, it either handles flow
control automatically, or it does not support flow control. In this case, obtain software that supports
flow control, or disable flow control by issuing the
AT
command.
You can connect but then can’t communicate with the remote modem.
or
You can connect but then the modems disconnect for no apparent reason.
Or
you can connect but
then the modem speed drops unexpectedly.
Your modem is designed to communicate at high speeds, but many factors contribute to the actual
speeds you achieve during communication sessions. Line noise, slow downloading, and
multitasking can be contributing factors.
Line Noise
Line noise is frequently a source of problems with high speed modem connections. The following
discussion provides an overview of potential problems with suggestions for troubleshooting.
Line noise is not a common cause of problems during fax calls. If it is, one of the following may
occur:
•
Your modem is able to connect, but fax transmissions are flawed (unreadable faxes, missing
sections).
•
Your modem connects but then disconnects unexpectedly.
If you think you are having fax line noise problems, try getting a clearer connection by redialing. If
that doesn’t help, wait a while and try redialing again. This should solve the problem. If necessary,
and if your fax software allows it, you can also try using your fax software to set your fax
transmission rate lower.
With data calls, line noise can cause numerous problems. In general, the faster you communicate,
the better your phone lines need to be. When you get up to 33,600 bps, it is critical that you have
clear lines from end to end. Line noise can cause the following problems when trying to make 9600
bps or higher data connections:
•
No connection
•
Connection, but only “garbage” characters appear on the screen
Problem:
Solution:
