@Sooty, @Geertjan, today I have finally finished this circuit. And its working, Apparently I mixed up to black wires so obvious it would not work:) With your help, I now succeeded getting this working like it should. The picture shows how the wires are fixed on the switch where also my Fibaro is located. The wiring on the other switch stayed the way it was.
Might be a help for others struggling with getting the fibaro to work with a "hotel switch".
In Homeseer Its added nicely.Now I am able to switch manually on and off, and also with the help of Homeseer/ Hstouch. When manually switched on or of the status is updated in Homeseer as well. Nice.

IMG_3818.JPG
You do not have the required permissions to view the files attached to this post.