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Alarms and Missed Alarms”. Once you have adjusted the sensitivity, you might need to decide
the timer value as well.The timer value refers to the time (in seconds) during which the camera
will not process new events.The purpose of this time limit is to avoid excessive and needlessly
redundant alarm communication between camera and the server. In this example, 30 seconds
is used as a timer value.
How does it work?
The actual motion
activity is marked
as blue in the timeline.When the motion occurs, the timer (red color) starts to count. If after the
end of time interval there is no more motion, the event will stop there and the camera will notify
NVR that it has returned back to normal mode. Should there still be a motion at the ending
point of time interval, the event will continue for another period of time interval.
The timer value is used not only for reducing redundant communication between the camera
and the server but also for avoiding false alarms in some cases. For example, when you
connect a conventional heat emitting lamp to digital output of the cube camera and you want
the lamp be turned on upon the PIR event, the lamp will be turned off after a certain amount of
time (the time length adjustment for digital output is explained in the step 3 of PIR installation).
The temperature change caused by the lamp turning off may itself trigger PIR sensor again,
creating an endless event loop. To avoid such endless event, it is recommended to let the PIR
timer value be bigger than the digital output timer value. For example, PIR timer is 60 seconds
and the digital output timer is 55 seconds. This way, the lamp has been turned off and the
temperature of the environment has fully stabilized by the 60th second when the camera is
ready to notice new events.
There is one more useful thing to know –NVR itself also has the filter to avoid redundant alarm
notices. As the minimum video recording length in NVR is at least 30 seconds, therefore NVR
has been designed not to respond to the events from the same camera within 30 seconds from
the start of the event. It means, if both PIR timer and digital output timer values are within 30
seconds then it does not matter which value is bigger –no endless alarm can possibly happen
due to de-activation of digital output. But if the timer values are more than 30 seconds then
make sure the PIR timer value is bigger than the digital output timer value in case you are
activating/deactivating external devices that may have impact on PIR sensor’s readings.
3. SET THE EVENT RESPONSE
Once you have configured the PIR as the event trigger, you can decide the appropriate event
responses. In this example, the event responses will be to activate digital output of the cube
