AT Commands Reference Manual - wireless netcontrol GmbH

Chapter 3: AT Commands Reference
Table 3-11: +CHLD Actions According to Call State and Operation (Cont.)
CHLD
Call State
0 - Release
Held Call
1- Release
Active Call,
Accept Held
Call
1x - Release
Active/Held
Call x from
MTPY Call
2 - Switch
Between
Held and
Active Call
2x - Active
MTPY Call to
Hold, Except
for Call x
3 - Add Held
Call to
Active Call
MTPY Active
Call and
Waiting Call
Releases
waiting call.
Releases active
call, accepts
waiting call.
Releases
specific active
call x. If x does
not exist, then
error 22.
Puts active call
on hold,
accepts waiting
call.
Split. If x does
not exist, then
error 22.
Error 3
Single Held
Call
Releases held
call.
Accepts held
call.
Releases held
call.
Accepts held
call.
Error 3 Error 3
MTPY Held Call
Releases held
call.
Accepts held
call.
Releases
specific active
call x.
If x does not
exist, then error
22.
Accepts held
call.
Error 3 Error 3
Single (or
MTPY) Active
Call and Single
(or MTPY) Held
Call
Releases held
call.
Releases active
call and accepts
held call.
Releases
specific active
call x.
If x does not
exist, then error
22.
Switches. Error 3 Makes a
conference
call.
Held (Single or
MTPY) Call and
Waiting Call
Releases
waiting call.
Accepts waiting
call.
Error 3
Accepts
waiting call.
Error 3 Error 3
Single (or
MTPY) Active
Call and Single
(or MTPY) Held
and Waiting
Call
Releases
waiting call.
Releases active
call, and accepts
waiting call.
Releases
specific active
call x.
If x does not
exist, then error
22.
Error 3 (too
many calls on
hold.
Error 3
Makes a
conference
call. Waiting
call is not
touched.
Split: Places the active MTPY call on hold, except for a specific call x.
Switch: Places the active call on hold and accepts the Held call.
Error 3: "Operation not allowed".
Error 22: "Not found".
Example
AT+CHLD=?
+CHLD: (0,1,1x,2,2x,3)
OK
AT+CCWA=1
OK
//Enable call waiting
RING
AT+CHLD=0
// MT voice call
April 15, 2010 H24 - AT Commands Reference Manual 3-27