I'm selling my Skaarhoj tally light system. I've been using it with a BlackMagic ATEM mixer. It connects to the mixer via an ethernet bridge (not included but widely available) and the individual tally lights are connected via ethernet cables. I'm not an expert with IP addresses but even I found it fairly easy to set up. Skaarhoj kit is beautifully designed, the tally lights themselves are very clear when lit and the system really adds to a multi camera set up when driven by a mixer like the ATEM.