Siemens MC55 - Manual (Page 17)

MC55 AT Command Set
1.4 AT command syntax
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MC55_ATC_V01.05 Page 17 of 469 2/10/04
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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.
Types of AT commands and responses:
1.4.1 Using parameters
• Optional parameters are enclosed in square brackets. If optional parameters are omitted, the current settings
are used until you change them.
• Optional parameters or subparameters can be omitted unless they are followed by other parameters. If you
want to omit a parameter in the middle of a string it must be replaced by a comma. See also example 1.
• A parameter value enclosed in square brackets represents the value that will be used if an optional parameter
is omitted. See also example 2.
• 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.
• If an optional parameter of a V.25ter command is omitted, its value is assumed to be 0.
AT command type Syntax Function
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 parameter or
parameters.
Write command AT+CXXX=<...> This command sets user-definable
parameter values.
Exec(ution) command AT+CXXX The execution command reads
non-variable parameters deter-
mined by internal processes in the
GSM engine.