Specifications

SIM900 AT Command Manual
SIM900_AT Command Manual_V1.03 50 12/24/2010
+CCWA: <n>
OK
AT+CCWA?
Parameter
See Write Command
Response
TA controls the Call Waiting supplementary service. Activation,
deactivation and status query are supported.
If <mode>≠2 and Command successful
OK
If <mode>=2 and Command successful
+CCWA:<status>,<class1>[<CR><LF>+CCWA:<status>,<class2>[...]]
OK
ERROR
If error is related to ME functionality:
+CME ERROR: <err>
Note: <status>=0 should be returned only if service is not active for any
<class> i.e. +CCWA: 0, 7 will be returned in this case.
When mode=2, all active call waiting classes will be reported. In this mode
the Command is abortable by pressing any key.
Parameters
<n> 0 Disable presentation of an unsolicited result code
1 Enable presentation of an unsolicited result code
<mode> When <mode> parameter not given, network is not
interrogated
0 Disable
1 Enable
2 Query status
<class> is a sum of integers each representing a class of information
1 voice (telephony)
2 data (refers to all bearer services; with <mode>=2 this
may refer only to some bearer service if TA does not
support values 16, 32, 64 and 128)
4 fax (facsimile services)
7 default(1+2+4)
<status> 0 not active
1 enable
Write Command
AT+CCWA=<n>[,
<mode>[,<class>]]

Unsolicited result code
RING
+CCWA: <number>,<type>,<class>[,<alpha>]