Line monitoring - DWA bus

The ultrasonic interior movement detector and the emergency current siren are connected via the DWA bus. As soon as the anti-theft system has been activated, the DWA bus is monitored cyclically every 2 seconds.

If the anti-theft system does not register with the SINE within 3.2 s, an alarm is initiated.

The anti-theft system sends a line monitoring request on the DWA bus to the emergency current siren. The emergency power siren must respond within 100 ms. If no response is received, the anti-theft system triggers an alarm. The line monitoring facility is also active while the alarm is triggered.

The anti-theft system in the roof function center measures the system voltage. The line monitoring facility is switched off at a system voltage below 9 V. This avoids false alarms.