Sensor state (alive/unknown...)

  • Platform information:
    • Hardware: RasPi3 (openHABian/Mysensors Ethernet GW, RFM69), TpLink HS100s, arduinos with RFM69 and various sensors.
    • OS: openhabian, version:2.4.0-1
  • Issue of the topic:
    OpenHAB newbie, trying to understand how the system will show on UI if a sensor is not alive (use heartbeat, ACK, other, how?)
    Looking for tutorials, instructions, reading, help…
    Already turned ON Request heartbeat response, request ACK, Expected communication timeout, on various Mysensors things but when I turn a sensor off (cut power) the UI thing just stays at the last state.

Welcome to the openHAB Forum!

IMHO any sensor indication will remain at the last known state if you power-off the sensor .

If your sensor regularly updates an openHAB Item, you may find the expire binding useful.

You may find this design pattern useful:

Thanks for qick replies everyone.
Thanks for such a great complete lesson, Vincent.
I will study it carefully, it cetainly looks like THE answer to my request.