How to configure knx central function?

Hey Community,

I’m new to the OH2 configuration and do not now how to configure knx central functions as things and items.

Let’s assume I have a switch actor in my knx installation with two channels. Each channel is assigned a group address for switching this actor on and off. Now I define a third group address that is additionally assigned to both channels. Now I can switch both channels on and off with this central function. So how do I configure this central function in the new OH2 style?

Are we talking about listening Group Adress?

See the doc and search for listeningGA

Say you have button a and b with GA 1/1/1 and 1/1/2. the central button has GA 2/1/1.

You would use 1/1/1<2/1/1 for button a and 1/1/2<2/1/1 for button b.

Is this answering your question?

Hey Ralf,

only part of it. I already know how to attach more than one GA to a channel of a thing. But how to I configure the button c that will send this central GA. So let’s break it down to a configuration sample:

The knx.things would look like this:

Bridge knx:ip:bridge [
] {
    Thing device myactor "Actor one" @ "myhome " {
        Type switch : a "Switch a" [

        Type switch : b "Switch b" [

The knx.items would look like this:

Switch c "Switch c" { channel="knx:device:bridge:myactor:?" }

Switch a "Switch a" { channel="knx:device:bridge:myactor:a" }
Switch b "Switch b" { channel="knx:device:bridge:myactor:b" }

My problem now is, to which channel I have to link the item “Switch c”. For this channel I placed a question mark ("?") into the item definition. Because there is no third channel I can link this switch to.

Kind regards,


Sorry. I have not switched to knx2 for now. Cant help you really. What about adding another

        Type switch : c "Switch c" [

I don’t use KNX so I could be way off base, but I don’t think you need a Thing or Channel for this. This is what Groups are for.

Group:Switch:OR(ON, OFF) C

Switch ItemA (C) { knx channel link }
Switch ItemB (C) { knx channel link }

We have your two switches A and B linked to the proper KNX channels. Then you create a Group C and add A and B to that Group. Any command you send to C will get forwarded to all of it’s members. So if you C.sendCommand(ON) then A and B will also receive an ON command to turn ON.