Very basic question for KNX binding

Hello all,

I have little experience with KNX (I made the installation in my house, with Hager TX100, and switched to ETS recently), but I am new to OpenHAB. I installed version 2, read the docs. And now I will start KNX binding configuration. An item can listen to several group addresses. I am thinking, but I cannot find an example of when an item could be updated with several GAs. An item should be updated by the status of an actuator output, so in my opinion there should be only one GA updating the item, the GA representing the actuator output status. Because if several GAs have different statuses, there is an issue to update the item. Am I right ?

Could someone explain me / give me an example (or give me a link with more information) where several GAs could update the status of an item ?

Many thanks in advance.


You will have to define an item this way:

Switch myItem "my label [%s]" <myIcon> (myGroup) {knx="GA1+<GA2"}

myIcon and myGroup are optional (obviously), GA1 is the GA, which will be sent when switching the item from UI (or a rule), GA2 would be the GA, set by state of the actuator.

However, one could have an actuator which does not provide any state, but will react on more than one GA. In this case, you will have to define all GA which will change the actuator state. Therefore you could even define an item like:

Switch myItem "my label [%s]" <myIcon> (myGroup) {knx="<GA1+GA2+GA3..."}

Where all GA are bound to the actuator’s ‘switch input’. openHAB would then get the first state from GA1 when booting, and would update on any GA(1,2,3…) received from knx.

1 Like

Hello Udo,

It’s very clear. Indeed, I did not consider the case where no status object is present.

Thank you very much for your clear explanations.

Best regards.