Table of Contents
Advertisement
Changeover
between GPRS and
GSM operation
Remote
configuration via
GSM data
connection
7.4.1 Access protection
ZDUE-GPRS-PLUS-VI
Manual changeover between GPRS operation and GSM operation is not
necessary. GSM data calls (CSD) are accepted if
GPRS mode is deactivated, but the device is checked into the GSM
network
the device is logged into the GPRS network
the IP server is set up, but there is no active IP connection
CSD calls are rejected if
a CSD connection already exists
an active IP connection has been established (independent of the
data flow)
In order to accept the GSM data call the GPRS connection is terminated.
When the GSM data call is complete, the GSM data call is restarted, the
GPRS connection is re-established and the IP server is set up again
Remote configuration of the ZDUE-GPRS-PLUS-VI in GPRS mode is
possible via GPRS as well as via GSM connection.
Attention
For time-critical applications there can be limitations for GPRS
transmissions.
Although the transmission in the GPRS network generally only lasts a few
100s of milliseconds, due to the packet-switched infrastructure of the GPRS
network individual data packets may take quite a bit longer to arrive, i.e. up
to several seconds.
This can also lead to problems when time-critical control centre software is
used if it expects replies within a certain time after commands are sent out.
The ZDUE-GPRS-PLUS-VI in GPRS mode accepts exactly one active IP
connection at a time. If there is already an active IP connection to the ZDUE-
GPRS-PLUS-VI, further connection requests are rejected by the device.
Furthermore, the ZDUE-GPRS-PLUS-VI offers the possibility of regulating
the group of authorised clients. Two different mechanisms can be activated
independently of each other for this purpose:
GPRS Modes
Page 49 of 63
Advertisement
Table of Contents
