OH3: Group state aggregation and boolean algebra not configurable in Main UI


I recognized that it’s not possible to configure boolean algebra in the item settings of the Main UI.
With a textual configuration it’s e.g. possible to set up an item like this:

Group:Rollershutter:AND(100, 0) gRollershuttersPos "Position [%s]"

But in the Main UI configuration it’s not possible to select either AND, OR, NAND nor NOR:

Is there another way to set it up in UI?


It is not possible for the rollershutter type, but it is possible for other types.

If your group item is just tracking whether the shutters are fully opened or fully closed, then you might be able to get the functionality you need if you change its type from rollershutter to switch or contact.

Hi @JustinG, Good news!

But it sounds for me that I need then a rule to bring the current possition of a Rollershutter item to a Switch/Contact item. Am I right?

Because the solution before by simply adding it to the group gRollershuttersPos is no longer supported.

Rollershutter Rollershutter_Kitchen			"Door [%d %%]" <blinds>				(gRollershutters, gRollershuttersPos) {channel="knx:device:bridge:actuatorJAL081002:channelA"}
Rollershutter Rollershutter_Bedroom			"Door [%d %%]" <blinds>				(gRollershutters, gRollershuttersPos) {channel="knx:device:bridge:actuatorJAL081002:channelB"}

You don’t need a rule. I’m fairly certain that the OpenClose type automatically converts from percentage values to open or closed, but I admit, I don’t know what the full expected behavior would be if you use a contact group with rollershutter members. It is possible that percentage values of 0 and 100 are properly cast, but intermediate values are not.

If it doesn’t work directly you could create a series of contact items from the same channel as the rollershutter controls and place those contact items as members of a contact group with the boolean behavior you need.

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If it used to work I think it should still work. However, the UI I think is trying to be smart and only show those functions that are relevant given the Item type but it’s missing some uses. It’s not exactly intuitive that one could use AND with a Rollershutter, Dimmer, or Number Item.

File an issue on web-uis to open a conversation about this. In the mean time the work arounds would be one of the following:

  • define your Item in a .items file as you previously did
  • use the REST API to modify the aggregation function after you create the Group Item to be what you want, effectively bypassing the UI
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