Data Sheet

Smart Machine Smart Decision
shall be ignored since it is used for synchronization with PC tool. Only enter AT Command
through serial port after SIM800 Series is powered on and Unsolicited Result Code "RDY"
is received from serial port. If auto-bauding is enabled, the Unsolicited Result Codes
"RDY" and so on are not indicated when you start up the ME, and the "AT" prefix, or
"at" prefix must be set at the beginning of each command line.
All these AT commands can be split into three categories syntactically: "basic", "S parameter",
and "extended". These are as follows:
1.4.1 Basic syntax
These AT commands have the format of "AT<x><n>", or "AT&<x><n>", where "<x>"is the
Command, and "<n>"is/are the argument(s) for that Command. An example of this is "ATE<n>",
which tells the DCE whether received characters should be echoed back to the DTE according to
the value of "<n>". "<n>" is optional and a default will be used if missing.
1.4.2 S Parameter syntax
These AT commands have the format of "ATS<n>=<m>", where "<n>" is the index of the S
register to set, and "<m>"is the value to assign to it. "<m>" is optional; if it is missing, then a
default value is assigned.
1.4.3 Extended Syntax
These commands can operate in several modes, as in the following table:
Table 1: Types of AT commands and responses
AT+<x>=? Test Command The mobile equipment returns the list of parameters
and value ranges set with the corresponding Write
Command or by internal processes.
AT+<x>? Read Command This command returns the currently set value of the
parameter or parameters.
Write Command AT+<x>=<…> This command sets the user-definable parameter
values.
Execution Command AT+<x> The execution command reads non-variable
parameters affected by internal processes in the GSM
engine.
1.4.4 Combining AT commands on the same Command line
You can enter several AT commands on the same line. In this case, you do not need to type the
"AT" or "at" prefix before every command. Instead, you only need type "AT" or "at" the
SIM800 Series_AT Command Manual_V1.05 22 2014-07-31