Can I link items to multiple groups

Hi,
I am just starting with openhab and I have some problems understanding of the linking of items.
What I want is to create two groups one is used for a room which should contain temperatur measurement e.g. and another shall be a group for a graph containing all temperature.
But actually I cannot get an item to be part of two groups, in the modell view i can see that the linked item is always be part of one group only

.items file:

Group g_Badezimmer “Badezimmer” (g_OG) [“Bathroom”]
Group g_Temperature “Temperaturen” [“Indoor”]
Number:Temperature i_TEMP_GET “Actual temperature” (g_Badezimmer, g_Temperature) [“Temperature”] {channel=“homematic:HM-CC-VG-1:MEQ0463078:INT0000002:1#ACTUAL_TEMPERATURE”}

The item i_TEMP_GET is only present in Group g_Badezimmer how can i link it to multiple groups?

BR
Florian

Yes.
I think the “model view” is fibbing here.

Ah then it makes sense that I cant understand this :slight_smile:
Thx for reply

It’s not fibbing. Any Item can only be a member of one semantically tagged Group to be shown and used properly by the model.

Your second temperature group should not be a part of the model. But if all you are looking for is charting, you don’t even need this second group. Properly tag all your temp sensor Items with Measurement/Temperature and they will all appear on the Overview Page’s Properties tab under a Temperatures tab.

Notice that “Analyze All” button. Click that and you’ll get a chart for all the temp sensors.

You can customize the view through the controls at the bottom. Once you get it the way you want it, you can click “save” at the top right and it will create a new Chart page with all those settings.

And as written, you’ve used the wrong tag for the Temperature Group anyway. Indoor is a location tag. You would use it if you’ve defined your locations hierarchy to distinguish between Indoor and Outdoor. If you were to have this Temperature Group in the model, you would tag it with one of the Equipment tags, probably Sensor in this case. But if you do that, as I said above, you can only put that Temperature Equipment into one location. And all the Temperature Point Items can only be a member of that Temperature Equipment.

The model is intended to model your home automation based on location, not functionality. The functional grouping is handled through the tags (as shown above), not Group membership. You may still have a use for a functional Group (e.g. to trigger a rule) and you can create such a Group and add all your Temperature Items to that Group. Just leave the functional Group out of the model. Not all Items and Group have to be a member of the model.

It’s helpful for specifying the necessary persistence part, e.g. “persist all temp sensors”, by Group.

Might also have other applications e.g.with expire and a rule to detect failed sensors.

True, but to get the most out of MainUI it is best to leave the default persistence config which uses rrd4j and persists all Items by default. Then no matter where you are in MainUI, be it settings or Pages, you can generate a chart for anything that is chartable on the fly.

But, if you don’t want that, then defining a separate Group to control the persistence is still possible and encouraged. But, as explained above, that Group would not be a part of the model (i.e. don’t semantically tag it).