April 15, 2008 G24-L AT Commands Reference Manual 2-1
Chapter 2: Introduction to AT Commands
AT Commands Overview
AT commands are sets of commands used for communication with the G24-L cellular modem.
AT commands are comprised of assemblies of ASCII characters which start with the "AT" prefix
(except the commands A/ and +++). The AT prefix is derived from the word Attention, which
asks the modem to pay attention to the current request (command).
AT commands are used to request services from the G24-L cellular modem, such as:
• Call services: dial, answer and hang up
• Cellular utilities: send/receive SMS
• Modem profiles: Auto Answer
• Cellular Network queries: GSM signal quality
General Symbols Used in AT Commands Description
The following syntax definitions apply in this chapter:
Syntax Definition
<CR>
Carriage return character, specified by the value of the S3-register.
<LF>
Line-feed character, specified by the value of the S4-register.
<...>
Name enclosed in angle brackets is a syntax element. The brackets themselves do not
appear in the command line.
[...]
Optional sub-parameter of a command or an optional part of terminal information
response, enclosed in square brackets. The brackets themselves do not appear in the
command line. When the sub-parameter is not provided in the parameter type
commands, the new value equals its previous value. In action type commands, the
action should be performed on the basis of the recommended default setting of the
sub-parameter.
//
Denotes a comment, and should not be included in the command.
