Chapter 3:  AT Commands Reference
 April 15, 2008 G24-L AT Commands Reference Manual 3-263
Send DTMF
This proactive SIM service command requests the G24-L to send a DTMF string after 
successfully establishing a call. This command can be used at any time during a call. The G24-L 
does not locally generate audible DTMF tones to play to the user.
This command can be activated/deactivated by the user using the command +MTKP=24. The 
setting defined by the user is retained during the currently active call and is restored after a power 
cycle. If a DTMF command is sent to the G24-L while this command is disabled, the G24-L 
sends an "Unable to process" terminal response to the SIM.
The terminal response indicating that the command has been performed successfully is sent after 
the complete DTMF string is sent to the network by the G24-L.If the command is sent in idle 
mode, or if a call is terminated or put on hold before the complete DTMF string is sent to the 
network, the G24-L informs the SIM using terminal response 20, with the additional information 
"Not in speech call". If the user indicates the need to end the proactive SIM application session 
while the G24-L is sending the DTMF string, the G24-L stops sending the string and sends the 
following terminal response, "Proactive SIM application session terminated by the user".
If the SIM includes an alpha identifier in the command, the G24-L displays this string for the user 
in the form of a +MTKP unsolicited response. In all other cases, no information is sent to the user.
Command Type Syntax Response/Action Remarks
Set
+MTKP=24,<enable
/disable>
OK
or:
+CME ERROR: <err>
The Set command 
activates and deactivates 
the send DTMF 
command.
Unsolicited 
Response
+MTKP=24,<alpha identifier 
string>
Read
+MTKP? +MTKP: 24,<status>
The Read command 
displays the current status 
of the send DTMF 
command.