Digitax 4GMCU, Техническое руководство

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Leaving GPS on can be useful to have an immediate position fix at start-up, otherwise some time,
usually less than one minute, can be required for a cold fix.
Leaving the GSM on is used to remotely start the MCU.
This can be achieved by calling the MCU from the central, using the voice or data number. When the
AITP detects the first RING coming from the GSM, it can start-up the MCU.
In this case it is also possible to start the system in Stealth Mode, that means with an hidden user
interface, for example for alarm monitoring.
User applications can read Stealth status from the AITP and behave consequently.
Odometer
The AITP also provides Odometer functionalities to the applications.
Travelled distance can be either read, or read & resetted by DLL functions.
This is done by application polling. Otherwise it is possible to program 2 Overspeed and 1
Underspeed events, setting the speed threshold that need to be monitored and for how many
seconds this threshold have to be overcame before AITP declares the event and sends the
notification message.
Another message is sent to the application when the speed event is finished.
Wheel Code is the number of pulses received for every kilometre travelled.
To detect that it is possible to follow this
calibration procedure:
1. Go with the cars where you can travel 1 Kilometre more accurately as possible.
2. Set value 1 as Wheel Code
3. Select ”Ask 1 then reset” to reset counters
4. Select ”Ask Speed every 1 s”
5. Start the car and travel for 1 Kilometre looking a known reference
6. The final value read in ”Distance from last Reset” is the Wheel Code to be set.