User's Manual

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TECHNICAL MANUAL
Telit GM862 PCS
Tri Band GPRS Data Terminal System Rev.1
- GM862-PCS 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 serialised and flushed to the Terminal Equipment.
2.9.2.5 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 GM862-PCS closes the connection, deactivates the
GPRS context returning to command mode and issuing the NO CARRIER code.
2.9.3 Known limitations
The implementation of the EASY GPRS feature has the following known limitations:
- Only one socket can be opened at a time, no multiple socket connections can be made;
- Only the first GPRS context is associated with this feature;
- The closing of a socket implies always the deactivation of the GPRS context associated;
- It is taken for granted that external processor will be able to handle at least a limited v.24
implementation: RTS, CTS and, highly recommended, DCD lines; this because software flow
control is not applicable to the feature;
- Only Mobile initiated connections can be made, it is not possible to receive incoming TCP
connection requests;
- Due to the particularity of this feature, the flow control of both the directions uplink and
downlink is interlocked