OH3 Semantic model does not allow to extend equipment after changing type

Hi all,

I’ve managed to migrate with all my things to OH3. Great job by the way. The new UI is amazing. Maybe I don’t understand some parts of the semantic model and how it should be used in OH3.

I’ve created my equipment from things and also created items for their channels. Because they were not shown in the Overview -> Locations in MainUI. I thought I had to change their type to what they represent. Therefore I’ve changed them to switch/dimmer and so on. But after that I’m no longer able to add new items and link them to their channel using the MainUI. You can only link to other channels not creating new items for them.

I then looked for an example in the demo.openhab.org and found GroundFloor -> Kitchen.

It shows at least an equipment with items that represent attributes of it. What I really don’t understand is why should I also add them to the parent Kitchen group. At least in my mind it makes sense that the equipment is able to show/control it’s main purpose by using an appropriate type and link it to the “main” channel. But then you would have to change them back to group before you’re able to create and link new items.

Maybe someone can help me to understand what I misunderstood here.

I am just starting with this also but if you go to the Thermostat HVAC equipment item and enter the edit item view it allows you to enter aggregation values and type

Have a play there and I think it might solve your issue.

3 valve aggregated as valves

average temperature shows on tile on UI

Not sure if this is the best way yet but so far it works.

Hi @robmac,

thanks a lot for your answer. I haven’t thought about the group functionionality for equipment. But I still have issues if the member type is not the same for all.

Even if all are from the same type they could mean something different. Like battery level and type.

If equipment should not be used to group attributes, then I don’t understand how to use this. And why should attributes(items linked to channels) contain equipment/location names again. I know they are just items but what is the benefit of this semantic model tree if it’s not for an better overview/representation and automated interpretation. Or am I missing something here?

One of the examples also demonstrate an equipment with items that may not be used to aggregate a common value.


I don’t see what equipment should be used for if not to group items. But if you name them after their location then it will screw the auto generated representation. In my case I don’t like the demo representation of the equipment.

And if the blinds are not of type rollershutter instead of group they won’t be included in the icons for the location.

The following equipment will not be recognized in the locations overview.

But this will be recognized in the overview and you can’t add item bindings.


In my case the rollershutter does not only support up/down/stop but also set percentage. Which I guess most shutters do. And other linked channels from the shutter should be listed below the rollershutter too. Which is not possible if I create the Equipment as “Rollershutter - Equipment > Blinds”. I would then have to change Rollershutter back to group, add all items and change it back to Rollershutter again. And I don’t think that is the right way.

Oh my god a few searches later I now have found the root cause.

Because I haven’t found out how or what triggers the Location Semantic cards I tried a lot of stuff and made some wrong conclusions.

So equipment can stay as a group and you only have to apply the proper Semantic Class & Semantic Property.

In my humble opinion should be mentioned in the semantic model tutorial.

[Semantic Model | openHAB](https://OpenHAB | Semantic Model)

Solution from @Erik_Bergstrom - Thanks a lot for pointing that out.

And the link to the design spec from @ysc:

That is why there is a link to edit it on GitHub.:smiley:


I know that I can contribute to this project. And what you don’t know is that I’m already working on my end to do so. But I can’t contribute things that I didn’t know in the past.

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Glad to hear. My personal focus has been the Z-Wave backend stuff.