SIM300C AT Command Set
Confidential
SIMCOM
SIM300C_AT_V1.00 Page 5 of 180
1.3 Conventions and abbreviations
In this document, the GSM engines are referred to as following term:
1) ME (Mobile Equipment);
2) MS (Mobile Station);
3) TA (Terminal Adapter);
4) DCE (Data Communication Equipment) or facsimile DCE(FAX modem, FAX board);
In application, controlling device controls the GSM engine by sending AT Command via its serial
interface. The controlling device at the other end of the serial line is referred to as following term:
1) TE (Terminal Equipment);
2) DTE (Data Terminal Equipment) or plainly “the application” which is running on an
embedded system;
1.4 AT Command syntax
The "AT" or "at" prefix must be set at the beginning of each command line. To terminate a
command line enter <CR>.
Commands are usually followed by a response that includes.”<CR><LF><response><CR><LF>”
Throughout this document, only the responses are presented, <CR><LF> are omitted
intentionally.
The AT command set implemented by SIM300C is a combination of GSM07.05, GSM07.07 and
ITU-T recommendation V.25ter and the AT commands developed by SIMCOM.
Note: Only enter AT command through serial port after SIM300C is power on and
Unsolicited Result Code “RDY” is received from serial port. And if unsolicited result
code”SCKS: 0” returned it indicates SIM card isn’t present.
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
