Specifications
ISU AT Command Reference Phase VII AT Commands
Iridium Proprietary Version 2.45
20 June 2011 97
11.8 +CSDT – Sidetone
This is a new command for the 9555 Handset and the 9522LBT.
Exec Command: +CSDT=<sidetone enabled>
This command controls the transceiver board sidetone generation. Enabling sidetone will cause the
transceiver board to start sidetone generation. Disabling sidetone will cause the transceiver board to stop
sidetone generation. The following parameter values are currently supported:
< sidetone enabled >:
1 Enable sidetone
0 Disable sidetone
Query Command: +CSDT?
This command returns the current transceiver board sidetone generation state. 1 = enabled, 0 = disabled.
Test Command: +CSDT=?
Test command returns a list of valid values. Response is in the form:
+CSDT: list of supported modes
11.9 +CHLD – Call Hold and Multiparty
This command is added in 9555/9522B to support the features described in C7818-DREP-002. This
command was added in 9505A/9522A release IS09003.
Command Possible response(s)
+CHLD= None (command ignored without
error)
+CHLD=<n>
When command unsuccessful
+CME ERROR: <err>
When command successful
OK
Test command
+CHLD=?
List of supported <n>s
+CHLD:(0,1,1x,2,2x,3)
Note: While this command is implemented in Iridium ISU, it may not yet be supported in the Iridium
network. Stand by for an Iridium Technical Bulletin announcing network support for this feature.
This command is based on GSM 07.07 subclause 7.12, and is used to invoke the HOLD and MPTY
supplementary services for switching between held calls, etc. The values of <n> are the same as those that
a user can enter via a numeric keypad, as described in GSM 02.30 subclause 4.5.5.
This command is not abortable, and finishes without waiting for a response from the network. The
interaction of this command with other commands based on other GSM supplementary services is
described in the GSM standard.
The following parameter values are currently supported:
<n>:
“0” Releases all held calls or sets User Determined User Busy (UDUB) for a waiting call.
“1” Releases all active calls (if any exist) and accepts the other (held or waiting) call.