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AT Commands
with the exception of #: Backspace Character 22 , #: Cancel Character 23 ,
and #: End-of-line Character 24 .
• All characters preceding the #AT: Command Prefix 25 are ignored.
• Interpretation / execution of the command line starts with the reception of the first (and
also command-line terminating) #: End-of-line Character 26 .
• Characters after the initial #AT: Command Prefix 27 and before the #: End-of-line
Character 28 are interpreted as commands. With some exceptions, there can be many
commands in one command line.
• Each of the basic commands consists of a single ASCII letter, or a single ASCII letter
with a &prefix, followed by a numeric value. Missing numeric values are interpreted as 0
(zero).
• The following commands can't be followed by more commands on the command line.
They must always be the last commands in a command line. If they are followed by other
commands, these other commands are ignored. However, some of these commands take
command modifiers and it is possible that a following command is accidentally interpreted
as a command modifier. Therefore, care should be taken to not follow these commands
with any more commands on the same command line. Instead, they should be placed in
an own command line.
• #A: Answer Command 29
• #D: Dial Command 30
• #Z: Soft Reset Command 31
• A command line can be edited if the terminating #: End-of-line Character 32 has
not ben entered, using the #: Backspace Character 33 to delete one command line
character at a time. The initial #AT: Command Prefix 34 can't be edited/deleted (it
has already been processed, because upon reception of the #AT: Command Prefix 35 the
modem immediately starts command line parsing and editing, but not execution).
• The modem echoes command lines and edits when #E: Command State Character Echo
Selection 36 is on (surprise, surprise :-)).
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