Tabs (Tracknet) PIR Sensor way of measuring

• • Tracknet sensors work in a way that the signal goes up immediately when someone is detected, but only goes down after a few minutes. 
    → the signal goes from GREEN TO RED in real time, but goes from RED TO GREEN based on a fixed timer which cannot be shorter than 10 minutes
  • This means that human motion can only trigger the sensor to go from '0' to '1' , and not the other way around.
  • The shortest possible window we are technically able to achieve is 10 minutes.
  • Once the sensor goes up (ie presence detected), it can't change its state faster than 10min.
  • The decay we have (=the silhouette) is actually nothing more than a clock counting down until the next refresh, regardless of the presence during that window.
  • The reason for using this silhouette is to not to show it has been unoccupied for a few minutes, but to indicate the probability that it's still occupied is lowering.
    (It is because of this limitation that we set the std dashboards and real-times decays on 15 min this past year). 

Here's how this works from a signal point-of-view:

German version of this document: