Specifications

SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 222 12/24/2010
Request the IMSI AT+CIMI 460008184101641
OK
13.4 Call Control Commands
Demonstration Syntax Expect Result
Make a voice call ATD6241xxxx; OK
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>