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Using the internal web pages
The white block pattern indicates changes in the image. System noise can be removed by
lowering sensitivity until the white blocks vanish, as is the case with a still image.
7.7.5.5 VMD alarm
If movement is detected, a module alarm (VMD) will be generated and sent out over the
network using the (unsolicited) notification mechanism. Such alarms can be caught using
appropriate software.
Advanced settings
Frame rate divider [1…100].
Delay [1…10].
Event window size
[1…32] Number of frames evaluated at a time to determine if there
is a VMD alarm.
Event window low
mark/ hi mark
[0…31]. Thresholds determining if there is a VMD alarm. For more
details, refer to the note on Advanced VMD settings (below) and
figure 7.45.
Feedback position
Enables you to position the detection window (described in
section 7.7.5.4, not to be confused with an event window).
Enable feedback
The detection window (described in section 7.7.5.4) may be disabled
to prevent it from appearing in applications that display images from
the same video input.
Figure 7.43a (left), b (right)
VMD detection windows, with mask applied to the left half of the window. The small white blocks
indicate grid elements where change occurred above the sensitivity level. The summed change is
reflected in the bars on the right. The green one (left) is not reaching the lower threshold. The red
one (right picture) is extending past it, since this threshold is set much lower
Figure 7.44 VMD, Advanced settings
