I did some stability tests over hours - so far so good 
But I had some problems with a JMX Wifi to DMX Converter, so had to send it back and got today a new device. After bringing the new JMS into my Network, Photon 2 sends no DMX Data any more. I checked it with another app (Stagelights) which works flawless. I checked it with a second IPAD with a new Photon Installation - it works. Photons network IP on the first IPAD was always green. Finally I deinstalled Photon from my first IPAD and reinstalled it - after that it works.
Question: Could I change anything manually regarding the DMX device?