Zigbee devices 'online' even if they are powered off


I’m using the Zigbee binding for some time now. I’ve noticed that my bulbs are showing “online” in Paper UI, even if I unplugged them. Even if I restart the binding (or OpenHAB as a whole) while one of the bulbs is unplugged, it shows up “online” eventually. This is confusing, especially when I’m trying to troubleshoot issues. Is this some technical limitation? Or is there anything that can be done to improve this behavior?

Best regards,
Bart Kummel

General observation, the use of “ONLINE” in connection with Thing status leads to misunderstandings. It might be clearer if it said “PATH READY” or something like.

Consider a sleeping zwave battery device. We can send it a command - the controller will pass that along the next time it wakes up. It is available ONLINE even though it is inactive.
Consider a master-slave polled device (like Modbus). We can schedule a read poll, it is available ONLINE, although we have no idea if the device is working until after the scheduled read comes around.

That’s not to say your mains powered devices are being handled correctly, just to warn that “Thing ONLINE” maybe does not mean what you think. It’s often not a positive indicator, just an absence of failure.


AH, that explains it. I agree that the used terminology is a bit confusing then.

The ZigBee binding has a mechanism to detect devices being offline. It bases this on either the polling period, or the reporting period - if the binding misses reports twice, then it will set the device offline (there is 30 seconds margin). There is no way to detect immediately if a device disappears from the network without using polling or reporting.