Digitax 4GMCU, Техническое руководство

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During the shut down, applications are informed by the digital IPRESHUT signal that Windows is
closing and have 8 seconds to save all data and log-off.
IMPORTANT NOTE:
If an application is saving a big file which requires more time, the AITP will wait until the saving
operation is completed by monitoring the IDE channel activity.
Finally the MCU will be closed only after at least 8 seconds of IPRESHUT and only after at least 3
seconds of NO DISK ACTIVITY.
Main Power Loss and UPS Battery
An UPS battery is externally connected, and an intelligent battery charger ccontinuously operates in
order to change the battery whenever main power supply is connected, even if the MCU is off. In
order to reduce power consumption the battery charge is stopped after 4 hours if MCU is off and car
stopped.
The main use of the UPS battery is to allow a proper shut down in case of main power loss.
At any power failure, the UPS automatically starts to work, allowing the continuity of the operation.
This procedure is completely transparent to the system.
If the power is absent for more than 30 sec. (this time is user programmable) the regular shut down
procedure will start, like pressing the power button.
The UPS battery is oversized in order to be capable of supply power for several of these events even
without recharging.
In case of full discharge, the UPS battery needs more than 12 hours of normal connection to the main
battery to become fully charged, anyway, the system can operate properly while battery is charging.
The AITP continuously monitors main power voltage and ups voltage, and battery charge.
Those levels are available for the user application, by the AITP protocol.
A digital signal is also available, the ILOPOW, that is high when the system is running from the UPS
battery with main supply disconnected.
Power OFF using external input
The AITP can be configured to turn OFF MCU after a specified time that an high to low transition on
the special input 3 has occurred. When this happens, the regular shut down procedure is started and
then the MCU is powered OFF.
On board peripheral power
The user procedures must manage the power ON/OFF of the on board peripherals, in order to have
the GPS, and the GSM working only when needed to save power.
By default all devices are turned On at Windows start, this is done by the Autorun program.
User applications have some digital signals used to manage peripherals power:
The ODCBPOW signal, active high, turns on peripheral power supply;
The OGSMPD and the OGSMIGN are used to turn on/off the GSM Engine;
The OPOWGPS is used to turn on/off the GPS receiver
Note that these signals are also available for the AITP processor, so is possible to keep the GPS / GSM
powered even when the MCU is off. The GSM can be kept on for the Wake Up On Ring function, the
GPS can be switched on at regular times to have a ”quick start”, in order to reduce fix time when the
device is started.
NOTE:
keeping the GPS or the GSM on when the MCU is off, cause an higher power consumption (about
100mA) so be careful to have a car battery capacity bigger enough to satisfy this requirement