Bosch Appliances FW5.50 Reference check is selected Sensitivity, Trigger delay s, Global change

72 en Setting up VCA Camera Browser Interface

Sensitivity and Trigger delay [s] can only be changed if

Reference check is selected.

Sensitivity

The basic sensitivity of the tamper detection can be adjusted for the environmental conditions to which the camera is subject. The algorithm reacts to the differences between the reference image and the current video image. The darker the observation area, the higher the value that must be selected.

Trigger delay [s]

Set delayed alarm triggering here. The alarm is only triggered after a set time interval in seconds has elapsed and then only if the triggering condition still exists. If the original condition has been restored before this time interval elapses, the alarm is not triggered. This avoids false alarms triggered by short-term changes, for example, cleaning activities in the direct field of vision of the camera.

Global change (slider)

Set how large the global change in the video image must be for an alarm to be triggered. This setting is independent of the sensor fields selected under Select Area. Set a high value if fewer sensor fields need to change to trigger an alarm. With a low value, it is necessary for changes to occur simultaneously in a large number of sensor fields to trigger an alarm. This option allows detection, independently of motion alarms, manipulation of the orientation or location of a camera resulting from turning the camera mount bracket, for example.

Global change

Activate this function if the global change, as set with the Global change slide control, should trigger an alarm.

Scene too bright

Activate this function if tampering associated with exposure to extreme light (for instance, shining a flashlight directly on the objective) should trigger an alarm. The average brightness of the scene provides a basis for recognition.

AM18-Q0611 v5.50 2012.03 Software manual Bosch Security Systems