Siemens MC35 - Manual (Page 11)

AT Command Set
MC35_ATC_01_V03.02 Page 11 of 228 13.03.2002
1.3 Conventions
Throughout the document, the GSM engines are referred to as ME (Mobile Equipment), MS (Mobile
Station), TA (Terminal Adapter), DCE (Data Communication Equipment) 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 interface. The control-
ling device at the other end of the serial line is referred to as TE (Terminal Equipment), DTE (Data
Terminal Equipment) or plainly ´the application´ (probably running on an embedded system).
1.4 Supported character sets
The ME uses 2 character sets: GSM 03.38 (7 bit, see character tables in Chapter 9.5, pg. 224) and
UCS2 (16 Bit, refer ISO/IEC 10646). Also refer to Chapter 4.40 for information about selecting the
character set.
When using an ASCII terminal to write characters differently coded in ASCII and GSM (e.g. Д, Ц, Ь),
you need to enter escape sequences. Such a character is translated into the corresponding GSM
character value and when output later, the GSM character value is presented. Any ASCII terminal then
will show wrong responses.
Table 2: Character definitions depending on alphabet (examples)
GSM 03.38
character GSM character
hex. value Corresponding
ASCII character ASCII
Esc sequence Hex
Esc sequence
Ö 5C \ \5C 5C 35 43
" 22 “ \22 5C 32 32
ò 08 BSP \08 5C 30 38
@ 00 1) NULL \00 5C 30 30
1) Use of the GSM Null character may cause problems on application level when using a ´C´-function
as “strlen()“ and should thus be represented by an escape sequence.
1.5 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.
Table 3: 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.