Specifications

Smart Machine Smart Decision
SIM900_AT Commands Manual_V1.07 249 2012.12.10
MS makes a voice call
Hang up a call AT H OK
Call dropped
Make a voice call using the
last number facility. The initial
call is established and then
cancelled. The second call is
made using the previous dial
string.
ATD6241xxxx;
ATH
ATD L
OK
OK
OK
Example of a MT voice call
Make MT voice call to MS.
ATA
ATH
RING
RING
OK[accept call]
OK[hang up call]
Call related to supplementary
service: AT+CHLD. This
Command provides support
for call waiting functionality.
AT+CHLD=<N> Return
value:(0,1,1x,2,2x,3,4,6,
6x,7x,8x,9x)
Terminate current call and
accept waiting call.
Establish a voice call from
EVB, receive an incoming call
(incoming call accepts waiting
status), terminate active call
and accept incoming call. Note
call waiting must be active for
this option – use
"AT+CCWA=1,1” before
running this demonstration.
AT+CCWA=1,1
ATD6241xxxx;
<RX incoming call>
AT+CHLD=1
OK
OK
RING
+CCWA: "62418148 ",
129,1,""
OK
<waiting call active>
Set current call to busy state
and accept waiting call.
Establish a voice call from
EVB, receive an incoming call
(incoming call accepts waiting
status), place active call on
hold and switch to incoming
call. Terminate active call and
switch back to original call.
Note call waiting must have
been previously enabled for
this demonstration to work.
ATD6241xxxx;
<RX incoming call>
AT+CHLD=2
AT+CHLD=1
RING
+CCWA: "1391818
6089",129,1,""
OK
<waiting call active other call
on hold>
OK
<incoming call terminated,
dialed number now active>
Switch between active and
held calls.
Establish a voice call from
ATD6241xxxx;
<RX incoming call>
OK
RING
+CCWA: "1391818