Specifications

ISU AT Command Reference Command Overview
Iridium Proprietary Version 2.45
20 June 2011 9
3.5 Command Entry
An AT command is a string of characters sent by the DTE to the ISU while the ISU is in command mode.
A command string has a prefix, a body, and a terminator. The prefix consists of the ASCII characters AT
or at. The body is a string of commands restricted to printable ASCII characters. The default terminator
is the <CR> character.
AT command entry syntax is critical, and the following rules apply:
 All commands (apart from A/ and +++) begin with a prefix of AT or at.
 The commands in a command string (apart from A/ and +++) are executed only after the return or
enter key is pressed.
 Use of upper or lower case letters is allowed, but not a combination of both.
 The maximum number of characters in a command string is 128.
 If the numeric parameter n is omitted from the basic command entry, a value of zero is assumed for n.
 If an optional parameter is omitted from an extended command, the current value is implied. Optional
parameters are enclosed by square brackets ([...]) in this document.
 Multiple commands can be concatenated onto a single command line by separating the additional non-
prefixed commands with a space or a semicolon or with no separator whatsoever. In the 9555 and
9555A Handsets, some commands do not support concatenation in this way and these are identified in
this document with the note “This command does not support command concatenation in the 9555 and
9555A Handsets”.
 Spaces entered into a command string for clarity between the
AT prefix and the body of the command
are ignored. Likewise, spaces entered for clarity within the command body between alpha characters
and decimal parameters are ignored.
 The backspace or delete keys can typically be used to edit commands.
 Characters that precede the AT prefix are ignored.
 Ctrl-x can be used to abort a command line input.
Consider the following six commands to be entered in a single command line:
ATX0 (set basic command ATXn to n=0)
AT&V (execute basic command AT&V)
AT+GSN (execute extended command AT+GSN)
AT+CMEE=? (query the valid range of responses of extended command AT+CMEE)
AT+CPBR=1,12 (execute extended command AT+CPBR with parameters 1 and 12)
AT-MSVTR? (query the current setting of extended command AT-MSVTR)
The following are valid single command line entries of above six commands:
at x 0 &v +gsn +cmee=? +cpbr=1,12 -msvtr? (all lower case)
AT X 0 &V +GSN +CMEE=? +CPBR=1,12 -MSVTR? (all upper case)
ATX 0 &V +GSN +CMEE=? +CPBR=1,12 -MSVTR? (space omitted between AT and X)
ATX0 &V +GSN +CMEE=? +CPBR=1,12 -MSVTR? (space omitted between ATX and 0)
ATX &V +GSN +CMEE=? +CPBR=1,12 -MSVTR? (0 omitted from ATX0)