Справочник Пользователя для Telit Wireless Solutions Easy GPRS

 
 
 
 

 
 

80000ST10028 Rev. 0 - 02/01/07  

  

Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved 

 

page 18 of 35 

 

2.1.1.4  Request the GPRS context to be activated 

With the command #GPRS you can activate or deactivate a GPRS context INDEPENDENTLY from 
the TCP socket opening: 
 

AT#GPRS=1 activates the context, 
AT#GPRS=0 deactivates the context 

 
Therefore with the AT#GPRS=1 command the module: 
 

•  Telit module activates the context previously defined with AT+CGDCONT 
•  Telit module proceeds to the authentication with the parameters specified  

 
Note that activating a context implies getting an IP address from the network and this will be 
maintained throughout the session. 
The response code to the AT#GPRS=1 command reports the IP address obtained from the network, 
allowing the user to report it to his server or application. 
Deactivating the context implies freeing the network resources previously allocated to the device. 
 

2.1.1.5   Open the connection with the internet host 

With the AT command #SKTD (socket Dial) the TCP/UDP request to connect with the internet host 
starts: 
 

•  DNS query is done to resolve the IP address of the host name internet peer 

•  Telit module establishes a TCP/UDP (depending on the parameter request) connection with the 

given internet host 

•  Once the connection is up the module reports the code: CONNECT  

 
NOTE: all peer specifications of this socket Dial are within the command and not the one stored with 
#SKTSET command. 
From this moment the data incoming in the serial port is packet and sent to the Internet host, while the 
data received from the host is serialised and flushed to the Terminal Equipment. 
 
NOTE: when disconnecting the #SKTD command does not close the GPRS context, leaving it active 
for next connections until an AT#GPRS=0 command is issued or the network requests a context 
closing. 
 

2.1.1.6  Close the Socket without deactivating the context 

The connection can be closed for the following reasons: 
 

•  remote host TCP connection close 

•  socket inactivity timeout 

•  Terminal Equipment by issuing the escape sequence "+++" 

•  Network deactivation