Introduction To At Commands; At Commands Overview; General Symbols Used In At Commands Description; General System Abbreviations - Motorola g20 Developer's Manual

3.1

AT COMMANDS OVERVIEW

AT commands are sets of commands used for communication with the g20 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 g20 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
3.1.1

General Symbols Used in AT Commands Description

The following syntax definitions apply in this chapter:
Syntax
<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 TA 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.
3.1.2

General System Abbreviations

The basic system configuration contains a modem and a terminal.
The g20 is the modem and may be referred to as the DCE, the phone, the mobile or the radio.
The terminal may be referred to as the DTE or the TE
98-08901C68-O

Table 4. Syntax Definitions

Definition
3. INTRODUCTION TO
AT COMMANDS
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