Realizzer Supports ArtNET 2.0 DMX Input. To enable the ArtNET Input go to Input > DMX Input > ArtNET and select them. Now other Consoles should be able to find Realizzer using the ArtNET Poll.
The ArtNET Protocol specifies the beginning of Universes (called Ports) at 0. So on some consoles you have to patch your fixtures in Universe 0 to get the DMX Data in Realizzer on Universe 1. Finally Realizzer's Universes always start at 1.