AT Commands Reference Manual - wireless netcontrol GmbH

Chapter 2: Introduction to AT Commands
Command Argument Types
consists of either a numeric constant or a string constant.
consist of several parameters separated by commas.
Example of compound_value: ,,…,
Numeric Constants
Numeric constants are expressed in decimal, hexadecimal, or binary form. In the H24, the
definition of each command specifies which form is used for values associated with that
command.
String Constants
String constants consist of a sequence of characters, bounded at the beginning and end by the
double-quote character (").
Command Mode Types
Parameter Set Command Syntax
The terminal may store a value or values in a parameter by using the SET command.
The parameter definition indicates, for each value, whether the specification of that value is
mandatory or optional. For optional values, the definition indicates the assumed (default) value if
none is specified. The assumed value may be either a previous value (that is, the value of an
omitted sub-parameter retains its previous value), or a fixed value (for example, the value of an
omitted sub-parameter is assumed to be zero). Generally, the default value for numeric
parameters is 0, and the default value for string parameters is "" (empty string).
The following syntax are used for:
• Actions that have no sub-parameters: +
• Parameters that accept a single value: +=
• Parameters that accept more than one value: +=
Parameter Read Command Syntax
The terminal can determine the current value or values stored in a parameter by using the
following syntax: +?
Parameter Test Command Syntax
The terminal can test whether a parameter is implemented in the H24, and determine the
supported values, by using the following syntax: +=?
April 15, 2010 H24 - AT Commands Reference Manual 2-7