GLOBALSAT TR-206 - Manual (Page 40)

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4.3 GPRS connection
Normally TR-206 will setup GPRS connection before sending report and
disconnect after sending report. But TR-206 will try to keep GPRS always on-line in
one of the following conditions.
z In on-line mode
z In motion mode / static state and ‘RB’ is set.
z In motion mode / moving state and ‘RC’ is set.
In such condition, the device will check the connection periodically. The period is
defined by ‘E5’. If the connection is lost, the device will try to connect again. If ‘E6’
is set, device will send “OK” message when connection is recovered.
If the connection is kept for a long time without sending any message, GSM carrier
may terminate the connection intentionally. In some worst conditions, the carrier
may even reject further request for connection. Setting of ‘E4’ is used to overcome
this issue. TR-206 will disconnect and then re-connect after it has been on-line for
the time defined by ‘E4’.
In certain circumstances, the server may want the device to setup GPRS
connection for receiving command or configuration messages. ‘L4’ command is
used to achieve the purpose. TR-206 will connect to server immediately when
getting L4 command. After the connection is established, TR-206 will keep on-line
for an interval defined by E7. Server can send commands or configure the device
during the interval. If there’s no message received during the interval, the
connection will be terminated. If there is a message received in the interval, the
connection will be extended for another E7 time. Server can send L5 command to
terminate the connection immediately.
The related configuration parameters are listed in the table below.
Code
word
Parameters Value Description
D8
Report Media for L4
command
02=TCP
04=UDP
Connection protocol for
always on-line and “L4”
command.