GalileoSky GLONASS/GPS v5.1 (223) User’s Manual
GalileoSky Ltd
Page
20
7.7 Monitoring data transmission
Terminal allows specifying the list of preferred GSM/3G-networks. The main priority is given to the networks
from the beginning of the list. Every network is specified with country’s code and network operator’s code.
Terminal supports up to 30 networks (OPS0 command, section
Data transmission settings
). If it is impossible
to connect to one of the preferred networks, the Terminal connects to any network but doesn’t establish
connection
to
the server, thus voice communication and SMS will be available according to a tariff of the
installed SIM-card.
The Terminal allows data transmission to the main and backup monitoring servers. If there is only transfer to
the main server set, continuous connection will be maintained. If there is transfer to both servers set, the
Terminal is connected to the main server and then after the set period of time it breaks the communication
and connects to the backup server and etc. The Terminal accounts transmitted data separately for each
server, thus both will receive full archive with the track.
Data can be transmitted according to the GalileoSky or EGTS protocol (Protocol command, section Data
transmission settings).
By using the EGTS protocol the Terminal`s number parameter (ID command, section Data transmission
settings) specifies the object number by the authentification.
By using the GalileoSky protocol transmitted data can be coded; XTEA3 algorithm
(http://tomstdenis.tripod.com/xtea.pdf) is used for coding. Commands, responses and photos are not coded.
The data are archived in the internal flash-memory by default. During long periods without connection the
oldest records of the internal flash-memory may be erased by the new ones. In this case, it is recommended
to insert a microSD card and to adjust archive transmission from it (Archive command, section Service
commands).
7.8 Internal Archive Structure
The data archive can be stored on the internal flash memory or a
micro-SD card. The internal flash memory
card
is
used
by
default.
The Terminal stores the data from all the inputs and interfaces, even when they have no connected sensors,
in the internal flash memory archive. If it is unnecessary to store all the data, the dynamic archive can be
used (FLASHARCHIVE command, section Service commands). In this case, only the data selected in
configuration of the head and main packets will be saved (HEADPACK and MAINPACK commands, section
Server exchange protocol settings). Any change of configuration of the head and main packets when the
dynamic archive is on can cause flash memory formatting and data loss. The use of dynamic archive can
considerably increase the maximum number of stored points up to 58000.
By using the internal flash memory it is possible to choose the order in which points are sent to the server.
By default, the data are saved in the depth of the data store, i.e. current data are saved before older
data. Transfer in chronological order can be set by FLASHARCHIVE command. After changing the direction
of memorizing data the flash memory will be formatted and all previously stored data will be lost.
By using a micro-SD card the data are always sent in chronological order. Note that only current data are
used for the first packet.
7.9 Operation with two SIM-cards
The Terminal has 2 slots for installation of SIM-cards. Only one SIM-card can be active and support the
registration in GSM/3G-network at the same time. Each SIM-card has its own APN. If
a
PIN code is used, it
must be the same for both SIM-cards. The Terminal supports the following algorithm of SIM-card operation:
1.
Only one SIM0 card is always active.
2.
Automatic switching to the other card, if the data cannot be sent to the server within 9 minutes.
Switching occurs in cycles, i.e. first SIM0 is used, then SIM1, and after this SIM0 again.
3.
Switching between the SIM-cards according to the list of preferred GSM/3G-networks. If the Terminal
detects the availability of one of the specified GSM/3G-networks, it switches to the corresponding
SIM-card. If both networks specified for SIM0 and SIM1 are available at the same time, the
preference will be given to SIM0.
