Rainbow Electronics GM862-QUAD-PY - Manual (Page 20)

Easy GPRS User Guide
80000ST10028 Rev. 4 - 16/07/08
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 20 of 63
Another new feature is the possibility to associate any socket connection to a specific context, this
means that we can use different IP addresses for the connections (max 2). Socket identifier is called
Connection Id (selects which socket we want to use from 1 up to 6) and every Connection Id is
associated to a context.
2.1 Commands Overview
In the following paragraphs you can find new AT commands sequence that activates GPRS context,
sets and opens the socket connection. You can also find the explanation regarding new listen
command and how to use FTP and IP Easy at the same time.
NOTE: For more detailed AT commands and parameters definitions remember to consult the AT
Commands Reference Guide
2.1.1 Easy GPRS Outgoing Connection
The 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 required to 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
All these steps are achieved through AT commands. As for common modem interface, two logical
statuses are involved: command mode and data traffic mode.
• In Command Mode (CM), some AT commands are provided to configure the Data Module
Internet stack and to start up the data traffic.
• In data traffic mode (Socket Mode, SKTM), the client can send/receive a raw data stream which
will be encapsulated in the previously configured TCP / IP packets which will be sent to the other
side of the network and vice versa. Control plane of ongoing socket connection is deployed
internally to the module.