Specifications

SIM900 AT Commands Set
SIM900_ATC_V1.01 171 23.06.2010
8 TCP CLOSED/UDP CLOSED
9 PDP DEACT
In Multi-IP state:
0 IP INITIAL
1 IP START
2 IP CONFIG
3 IP GPRSACT
4 IP STATUS
5 IP PROCESSING
9 PDP DEACT
Reference Note
z This command is allowed to establish a TCP/UDP connection only
when the state is IP INITIAL or IP STATUS when it is in single state.
In multi-IP state, the state is in IP STATUS only. So it is necessary to
process “AT+CIPSHUT” before establish a TCP/UDP connection with
this command when the state is not IP INITIAL or IP STATUS.
z When in multi-IP state, before executing this command, it is necessary
to process” AT+CSTT, AT+CIICR, AT+CIFSR”.
8.2.3 AT+CIPSEND Send Data Through TCP or UDP Connection
AT+CIPSEND Send Data Through TCP or UDP Connection
Test Command
AT+CIPSEND=?
Response
1) If single IP connection (+CIPMUX=0)
+CIPSEND: <length>
OK
2) If multi IP connection (+CIPMUX=1)
+CIPSEND: <0-7>,<length>
OK
Read Command
AT+CIPSEND?
Response
1) If single IP connection (+CIPMUX=0)
+CIPSEND:<size>
OK
2) If multi IP connection (+CIPMUX=1)
+CIPSEND:<n><size>
OK
Parameters
<n> a numeric parameter which indicates the connection number
<size> a numeric parameter which indicates the data length sent at a