KNX2 sending commands twice which leads to errors and slowdowns

Hi all,

I already have a solution to my problem but wanted to make an entry here as I did not really find the exact same issue described (even there are a lot that look similar).

I migrated to the new knx2 binding and had the following problem. When I turned something on via openhab (Basic UI for example), the ON I got the following in the ETS group monitor:

  • Received command ON
  • Sending state ON
  • Received command ON

In openhab I got the exception that I did not get a confirmation (probably for the second ON command).
This led to a lot of exceptions when using knx2, everything was super slow and basically nothing worked as expected. I was basically able to turn a light on, but I had a 20s delay…

I have more details (stacks etc. if someone is interested), but the root cause was the following.

I configured the " localSourceAddr=" wrong for my knx bridge. I took the physical address for this device from ETS, but it seems it was wrong. I found that problem as I wanted to do a firmware update of my knx gateway and this also did not work with this address.

Everything worked perfectly when doing it with the default address (0.0.0). So just wanted to let you know that a wrong localSourceAddr would mean:

  • You get item state updates from the knx bus without problems
  • You can switch items,…
  • You get a lot of exceptions when switching items and everything is super slow

It would be good if there could be some kind of verification if thats the right address, maybe the knx binding could identify it, or query something or whatever.