AT Command Set
MC35_ATC_01_V05.00 Page 15 of 256 15.07.2002
1.3 Conventions Throughout the document, the GSM engines are referred to as ME (Mobile Equ ipment), MS (Mobile
Station), TA (Terminal Adapter), DCE (Data Communication Eq uipment) or facsimile DCE (FAX mo-
dem, FAX board). When the Siemens product names are required to distinguish the two models ,
MC35 is short for the engine type and MC35T for the terminal.
To control your GSM engine you can simply send AT Commands via its serial interfac e. The control-
ling device at the other end of the serial line is referred to as TE (Terminal Equ ipment), DTE (Data
Terminal Equipment) or plainly ´the application´ (probably runn ing on an embedded system).
The "AT" or "at" prefix must be set at the beginning of each comm and 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.
Table 2: Types of AT commands and responses
Test command AT+CXXX=? The mobile equipment returns the list of parameters and
value ranges set with the corresponding Write command
or by internal processes.
Read command AT+CXXX? This command returns the currently set value of the pa-
rameter or parameters
Write command AT+CXXX=<...> This command sets user-definable parameter values.
Execution command AT+CXXX The execution command reads non-variable parameters
affected by internal processes in the GSM engine.
· Default parameters are underlined throughout this document.
· Optional parameters are enclosed in square brackets. If optional parameters are omitted, the cur-
rent settings are used until you change them.
· Optional parameters or subparamters can be omitted unless they are followed by other parame-
ters. If you want to omit a parameter in the middle of a string it must be repl aced by a comma. Ex-
ample:
AT+CPBW=,<number>,<type>,<text> writes a phonebook entr y to the first free memory location.
AT+CPBW=<index>,<number>,<type>,<text> writes a phonebook entry to the memory location
specified by <index>.
· When the parameter is a character string, e.g. <text> or <number>, the string must be enclosed in
quotation marks, e.g. "Charlie Brown" or "+49030xxxx". Symbols within quotation marks will be
recognized as strings.
· All spaces will be ignored when using strings without quotaton marks.
· It is possible to omit the leading zeros of strings which represent numbers.
· In case of using V.25ter commands without giving an optional parameter, its value is assumed to
be 0.