The driver blows into the alcohol sensor (WAB) to verify that they are under the legal limit, which will
release the immobiliser allowing the vehicle to start.
Drivers who are over the legal limit will be prevented from starting their vehicles by the unit remaing immobilised
The  WAB can be configured to lock  out or allow multiple resets to relaese the immobiliser thus allowing
a driver to wait untill their blood alcohol level drops and blow into the sensor again.
If the Re-test Feature is selected then at pre-difined intervals the system will require a new breath sample to be
provided. This ensures that the drivers are re-tested at random while on route.
All sample information and failures are stored in a non volatile memory with date and time stamp.
If a failure occurs this can be automatically communicated if the optional GSM module is connected.
The WAB has a built in temperature sensor therefore with the unit permanently fitted to the vehicle, warm up times
in Winter and cooling down times in Summer are significantly reduced.
All parameters in the  WAB and VBS are configurable to meet operating requirements.