0049-1800-xxx 326X V.34, V.34-SDC and V.32bis Series Modem – USER’S GUIDE 02/23/2010
Rev. A
Page 71
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WHAT IS THE ATTENTION (AT) COMMAND SET?
The AT command set is a collection of commands that let you configure a modem directly from an
asynchronous terminal or PC keyboard. The characters
AT
are a prefix to the commands you issue to your
modem. When you type AT, you are asking for the modem’s
at
tention. For instance, to disconnect a telephone
call, you type
AT
for attention and
HO
for on-hook (hang up).
You can also use AT commands to configure a remote modem (refer to Chapter 2, Front Panel Operation, of the
326X Series Modem Reference Guide
for details).
What Role Does Communications Software Play?
Some communications software packages “interpret” AT commands with pull-down menus or graphics,
making familiarity with the AT command syntax unnecessary.
Communications software packages that directly support the 326X Series Modem usually support all of
the modem’s AT commands (the industry standard commands AT, AT&,
and
the Raymar-Telenetics-
enhanced commands AT
*
).
Communications software packages that support a Hayes-compatible selection do not support the
Raymar-Telenetics-enhanced commands (AT
*
). You can enter these commands yourself to modify
option settings if required by your application.
Check the documentation included with your communications software package to determine whether
you need to use AT commands directly.
USING AT COMMANDS
AT commands are accepted by the modem in
command mode
or
escape mode
.
•
The modem is in command mode when it is disconnected from the telephone line.
•
You can enter
escape mode
and issue AT commands during a connection (the escape se++ is
described later in this chapter).
Entering AT Command Lines
To enter a single AT command line:
1.
Enter the prefix AT
: The characters
AT
(upper-case or lower-case, but not mixed) must begin the
command line.
2.
Enter an AT command
.
For example:
D
instructs the modem to dial a call.
H
instructs the modem to hang up. A numeric
character (for example, 2) following an AT command instructs the modem to use a
specific command option. If a numeric character is not indicated, the modem assumes
the
0
(zero) option.
