Synxcom SM9234D, User Manual

Page: 38 / 216

AT Commands
Page 38
Action Test Command Syntax
The DTE may test if an action command is implemented in the modem by using
the syntax:
+<name>=?
If the modem does not recognize the indicated name, it returns an ERROR result
code and terminates processing of the command line. If the modem does recognize
the action name, it returns an OK result code. If the named action accepts one or
more subparameters, the modem sends an information text response to the DTE,
prior to the OK result code, specifying the values supported by the modem for
each such subparameter, and possibly additional information. The format of this
information text is defined for each action command.
Parameter Commands
Parameter Types
Parameters may be defined as "read-only" or "read-write". "Read-only" parameters
are used to provide status or identifying information to the DTE, but cannot be set
by the DTE; attempting to set their value is an error. In some cases (specified in
the description of the individual parameter), the modem may ignore attempts to set
the value of such parameters rather than respond with an ERROR result code, if
the continued correct operation of the interface between the modem and DTE will
not be affected by such action. Read-only parameters may be read and tested.
"Read-write" parameters may be set by the DTE, to store a value or values for
later use. Read-write parameters may be set, read, and tested.
Parameters may take either a single value, or multiple (compound) values. Each
value may be either numeric or string; the definition of the parameter will specify
the type of value for each subparameter. Attempting to store a string value in a
numeric parameter, or a numeric value in a string parameter, is an error.
Parameter Set Command Syntax
The definition of the parameter 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 (i.e., the value of an omitted subparameter retains its previous
value), or a fixed value (e.g., the value of an omitted subparameter is assumed to
be zero). Generally, the default value for numeric parameters is 0, and the default
value for string parameters is "" (empty string).