Function of ATA (Anti-theft Alarm system)
When the ATA is switched on, a visual and acoustic alarm is triggered when opening:
a door
the vehicle with the emergency key
the bonnet
the tailgate or rear-end door
After locking the vehicle with the key, the ATA system is automatically primed.
When the ATA system is primed, indicator lamp 
flashes in the overhead control panel.
ATA is automatically deactivated in the following situations:
after unlocking the vehicle with the key
when the key is inserted into the ignition lock
The alarm will not be deactivated, even if you immediately close the open door that has triggered it, for example.