Specifications

ISU AT Command Reference Phase III AT Commands
Iridium Proprietary Version 2.45
20 June 2011 52
7.5 Xn - Extended Result Codes (Revised)
Select the response set to be used by the ISU when informing the DTE of the results of a command or data
or voice call.
0 OK, CONNECT, RING, NO CARRIER, NO ANSWER and ERROR.
CONNECT response is used to inform of a data call connection; OK response is used to
inform of a voice call connection.
1 As X0 plus CONNECT x, where x is the DTE speed.
CONNECT x response is used for data calls only.
2 As X1 plus NO DIALTONE.
3 As X2 plus BUSY.
4 As X3 plus CARRIER x, PROTOCOL: and COMPRESSION:, where x is the line speed
(default).
CARRIER x, PROTOCOL:, and COMPRESSION: responses are used for data calls
only.
Note that the Wn command limits which connection related responses will be reported.
7.6 &Dn - DTR Option (Revised)
Set the ISU reaction to DTR signal.
0 DTR is ignored in all modes. A DTR signal input is not needed when set to &D0.
For all other &Dn settings, the following applies.
DTR must be ON during on-hook command mode. If DTR transitions from ON to OFF during on-hook
command mode, operation will be locked after approximately 10 seconds. On-hook command mode
operation will resume when DTR is restored ON.
DTR must be ON at call connection
DTR must be ON during both in-call command mode and in-call data mode. Reaction to DTR ON to OFF
transitions during in-call command mode and in-call data mode is determined by the &Dn setting as shown
below. Note that the +CVHU command can be set to override these specified reactions.
1 If DTR transitions from ON to OFF during in-call command mode, and DTR is restored ON
within approximately 10 seconds, the call will remain up. If DTR is not restored ON within
approximately 10 seconds, the call will drop to on-hook command mode.
If DTR transitions from ON to OFF during in-call data mode, the mode will change to in-call
command mode. If DTR is restored ON within approximately 10 seconds, the call will
remain up. If DTR is not restored ON within approximately 10 seconds, the call will drop to
on-hook command mode.
2 If DTR transitions from ON to OFF during either in-call command mode or in-call data mode,
the call will drop to on-hook command mode (default).
3 If DTR transitions from ON to OFF during either in-call command mode or in-call data mode,
the call will drop to on-hook command mode and the ISU will reset to AT command profile 0.