Rainbow Electronics GM862-QUAD-PY - Manual (Page 36)

Easy GPRS User Guide
80000ST10028 Rev. 4 - 16/07/08
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 36 of 63
2.4 Examples
1
2.4.1 Easy GPRS - HTTP client application
Let’s suppose we want to connect our embedded device to an HTTP server and retrieve an HTML
page using the EASY GPRS feature.
Initial data:
Server to be contacted www.telit.com
Application Layer Protocol HTTP1.0 (RFC1945);
HTTP1.1 (RFC2068)
Page to be retrieved homepage of server
GPRS settings
APN
internet.gprs
IP of GPRS device dynamically assigned by
the network
DNS assigned by the network
USERID EASY GPRS
PASSWORD EASY GPRS
Socket parameters
Connection Identifier
1
Packet size (used by
TCP/UDP/IP stack for data
sending)
300
Socket inactivity timeout 90
Connection timeout 600
Data sending time out 50
Checking on the RFC990 the HTTP service we can found that the port 80 is dedicated for HTTP
service, therefore our HTTP server will be waiting for incoming connections on that port and we will fix
the EASY GPRS port to be contacted on the remote server exactly to 80.
Second thing we have to discover is whether the transport protocol has to be TCP or UDP; on the
RFC1945 we can read that the HTTP Application layer protocol is meant to be on top of TCP/IP
protocol, therefore the transport protocol choice will fall on TCP.
Now we have all the information needed to configure our system.
With our microcontroller we issue to the Telit module the following AT commands:
AT+CGDCONT = 1,"IP","internet.gprs","0.0.0.0",0,0<cr>
(GPRS context setting)
1 NOTE: For the detailed information about AT commands reported in examples please consult AT Commands
Reference Guide