Data Sheet

SIM900 AT Commands Set
SIM900_ATC_V1.00 196 15.01.2010
Reconnect a context using the terminal
equipment
Resume the data transfer
AT+CGDCONT=1,”I
P”
ATD*99#
+++
ATO
OK
CONNECT
<data>
OK
CONNECT
<data>
*Quality of Service (QOS) is a special parameter of a CID which consists of several parameters itself.
The QOS consists of
The precedence class
The delay class
The reliability class
The peak throughput class
The mean throughput class
And is decided in “requested QOS” and “minimum acceptable QOS”.
All parameters of the QOS are initiated by default to the “network subscribed value (=0)” but the
QOS itself is set to be undefined. To define a QOS use the AT+CGQREQ or AT+CGQMIN
Command.
Overwrite the precedence class of
QOS of CID 1 and sets the QOS of
CID 1 to be present
AT+CGQREQ=1,2 OK
Response: all QOS values of CID 1
are set to network subscribed except
precedence class which is set
to 2
AT+CGQREQ? +CGQREQ:1,0,0,0,0,0
+CGQREQ: 3,0,0,3,0,0
OK
Set the QOS of CID 1 to not present.
Once defined, the CID it can be
activated.
AT+CGQREQ=1 OK
Activate CID 2, if the CID is already
active, the mobile returns OK at once.
If no CID is defined the mobile
responses +CME ERROR: invalid index.
Note: If the mobile is NOT attached
by AT+CGATT=1 before activating, the
attach is automatically done by the
AT+CGACT Command.
AT+CGACT=1,2
AT+CGACT=1,3
OK
OK
Use the defined and activated CID
to get online. The mobile can be
connected using the parameters of
appointed CID or using default
parameter
AT+CGDATA=”PPP”,
1
CONNECT
The mobile supports Layer 2 Protocol (L2P) PPP only.