Alarm Horn: Description and Operation

Emergency Siren with Integrated Tilt Sensor (SINE)

The emergency siren communicates with the DWA over a bi-directional line (DWA K bus). The emergency siren is flashable and has diagnostic capability.

If the alarm is triggered, the emergency siren issues an acoustic signal. A short acoustic signal is also triggered when locking/unlocking.




Detected alarm triggers are communicated to the DWA control unit, which then activates the alarm.

The emergency siren has an independent voltage supply and additionally monitors the voltage supplied of the vehicle battery. It also monitors tampering with any of its own connector leads.

The independent voltage supply allows the emergency siren to generate an alarm when the vehicle voltage supply is disconnected.

The independent voltage supply is provided by rechargeable lithium cells.
The emergency siren can detect:

- A voltage drop in the vehicle battery due to a break in the wiring
- A voltage higher than 16 V
- A voltage drop from a value of 7.5 V to 6.5 V in less than 40 minutes

When armed,the emergency siren monitors the vehicle voltage over the range 6.5 V < +U b<16 V. If the actual voltage value drops below or exceeds these values, the independent alarm is generated immediately.

The emergency siren monitors the connecting lines +U b , GND (ground) and DWA K bus. If these line are cut, the independent alarm is sounded immediately.

The tilt sensor monitors the horizontal position of the vehicle and also has the task of detecting tire and wheel theft as well as attempts to tow away the whole vehicle.

The present parked position of the vehicle is stored together with the components "longitudinal angle" and "transverse angle". If a defined change of angle is exceeded in the longitudinal direction and/or the transverse direction, an alarm telegram is sent to the DWA interior sensor.

After the initial alarm is generated, the alarm sensitivity is raised, the result is that a second alarm is triggered with less movement.