If I link an Item to any of the alarm channels of my Fibaro FGSD-002 smoke detectors (version 3.2), the state returned is always NULL. This was already the case on openHAB 2.5 but it still remains true on openHAB 3. See for instance the result of querying the REST API (as is done through nodeRED): …

[image] shutterfreak: I believe that the Z-Wave binding never returns the actual alarm channel values. Is the device changing into alarm state? Ie is there a heat alarm active since the binding started? If not, then it’s not possible for the binding to get the state if the device doesn’t sen…

[image] shutterfreak: the state returned is always NULL. NULL is a special state that indicates that the Item has never received an update. So either the device has never returned a value for the alarm channel or the database entry for that device is wrong and it doesn’t really have an alarm …

Hi Rich, The channels are given in the screenshot below: [Screenshot 2021-06-17 at 17.07.35] Here’s a detail on the Heat Alarm channel (which is linked to Switch item L1_Hall_SmokeDetector_ZWave_HeatAlarm: [Screenshot 2021-06-17 at 17.09.14] I believe that the Z-Wave binding never returns the…

At this point I think you’ll need to put the binding into debug mode and capture some of the messages that are generated by this node and see what’s being sent. You also might try manually pressing the test button on the alarm to make it go off. On some models that will cause it to report back to t…

Thanks @chris for this clarification. Makes perfect sense. So any Z-Wave device that can generate an Alert will only send alert triggered and alert cleared messages. A NULL state simply means that no alert messages have been received yet. That is of course a weak point of Z-Wave for alarms as the…

[image] shutterfreak: So any Z-Wave device … How each device behaves is up to the makers, often with some choices for the user. Zwave just provides the communication medium.

[image] shutterfreak: That is of course a weak point of Z-Wave for alarms as there’s no way to know if an alert is active when a system restarts. I agree - I had this discussion with the guys at the Alliance a couple of years back and their opinion was “why is that a problem”. It’s not really…

Sure, but any serious “life safety” (e.g. fire alarm) system should provide integrity checks, or it’s just a toy. Note, that’s the system, not specifically the sensor. In openHAB then, it might be down to us to add the necessary smarts. In the smoke alarm case, we can make inferences - if the dev…

[image] rossko57: Sure, but any serious “life safety” (e.g. fire alarm) system should provide integrity checks, or it’s just a toy. True, but that’s not the point here. IT has been stated many times, and I think written in the Z-Wave docs, that Z-Wave should NOT be used for safety of life app…

[image] chris: True, but that’s not the point here. IT has been stated many times, and I think written in the Z-Wave docs, that Z-Wave should NOT be used for safety of life applications. I think it’s also stated like this in OH documents. So it is supplementary information and should not be reli…

[image] shutterfreak: The smoke detector manufacturer must ensure their products comply with the regulations of the markets they serve. But a smoke detector alone is not a “fire alarm” within the meaning of any regulations, any more than a fly detector would be. So there’s no ‘must’. Topic …

Fibaro FGSD-002 alarm Items invariably report NULL state

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rossko57 (Rossko57) June 20, 2021, 3:45pm 12

But a smoke detector alone is not a “fire alarm” within the meaning of any regulations, any more than a fly detector would be. So there’s no ‘must’.
Topic touched on here -

It’s possible to make standalone units or sub-systems that comply, and happen to have zwave capability as an ‘extra’.