Rainbow Electronics GT863-PY - Manual (Page 27)

GT863-PY Terminal Product Description
80269ST10026a Rev. 0 - 27/09/06
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Right reserved
page 27 of 50
If a host nick name has been given then, while opening the connection in response to the
AT#SKTOP command, the module will autonomously activate a GPRS connection and query its
DNS to obtain the IP address relative to the host nick name provided. This process of context
activation and DNS query may require a bit more time and requires that the GPRS network
coverage is good enough to permit data transfers.
3.1.2.4 Open the connection with the internet host
With the AT#SKTOP all the process required to connect with the internet host starts:
• GT863-PY activates the first context
• GT863-PY proceeds to the authentication
• Eventually does the DNS query to resolve the IP address of the host name internet peer
• GT863-PY 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
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 serialized and flushed to the Terminal Equipment.
3.1.2.5 Close the Socket and deactivate the context
The connection can be closed because of:
• remote host TCP connection close
• socket inactivity timeout
• Terminal Equipment by issuing the escape sequence "+++"
• Network deactivation
NOTE: if in the raw data to be sent there's an escape sequence, then the TE must work it out and
sent it in a different fashion to guarantee that the connection is not closed.
The pause time is defined in the parameter S12.
On the reception of an escape sequence the GT863-PY closes the connection, deactivates the
GPRS context returning to command mode and issuing the NO CARRIER code.
3.1.3 Enhanced EASY GPRS Outgoing connection
The New Enhanced EASY GPRS feature provides a way to place outgoing TCP/UDP connections
and keep the same IP address after a connection, leaving the GPRS context active.
The steps that will be required open a socket and close it without closing the GRPS context are:
• configuring the GPRS Access
• configuring the embedded TCP/IP stack behaviour
• defining the Internet Peer to be contacted
• request the GPRS context to be activated
• request the socket connection to be opened
• exchange data
• close the TCP connection while keeping the GPRS active