Thank you both for the reply,
I configured it now manually as a different radius client, this also works for now.
I'll wait for the stable 2.0 release and see then if I can get it to communicate with the controller.
It's a Ruckus 7942. It detects the controller normally by broadcast (on the same subnet)
A plan B is the 43 option (this is undocumented, their support staff sent me information about it)
It supports DNS, but you need to buy the flexmaster software, but that would be a substitute for the controller, so a waste of money, and you'd need a server running for it.