Rainbow Electronics GT863-PY - Manual (Page 29)

GT863-PY Terminal Product Description
80269ST10026a Rev. 0 - 27/09/06
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page 29 of 50
• 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.
3.1.3.5 Open the Connection with the Internet Host
With the new command #SKTD (socket Dial) the TCP/UDP request to connect with the internet
host starts:
• 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
Note that the 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 serialized and flushed to the Terminal Equipment.
NOTE: this command differently from the AT#SKTOP DOES NOT automate all the process of
activating the GPRS, if no GPRS is active the command reports ERROR; therefore before issuing
this command the GPRS shall be activated with AT#GPRS=1 command.
In the same manner, 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.
3.1.3.6 Close the Socket without deactivating 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 if the socket was opened with the AT#SKTD command,
the GT863-PY closes the connection, does not deactivate the GPRS context and returns to
command mode issuing the NO CARRIER code.
3.1.4 Enhanced EASY GPRS Incoming Connection
The New Enhanced EASY GPRS feature provides a way to accept incoming TCP/UDP
connections and keep the same IP address after a connection, leaving the GPRS context active.