Bosch Appliances NDN-921 Tamper detection, Reference check is selected Sensitivity, Global change

88 en Advanced Mode FlexiDomeHD 720p IP Camera

Tamper detection

Detect tampering of cameras and video cables by means of various options. Run a series of tests at different times of the day and night to ensure that the video sensor is operating as intended.

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.

AR18-10-B013 v1.52 2011.06 Installation and Operation Manual Bosch Security Systems