Since some time, I polled the Nuki Lockstate and and wrote it into a variable in Homematic/CCU.
But as this required frequent polling, I always wanted to use the callback function.
Since I don’t know in depth how to ensure that the CCU listens to data that is sent automatically, I found a way to receive the Callback and only then poll the Lockstate from the Nuki. This avoids frequent polling and ensures that the the lockstate is promptly updated when it changes.
I described it below, any feedback in the Homematic Forum is welcome.
Nuki Integration into Homematic