Hiya
They work by varying the AC input voltage.
The data cable of the power bar plugs into a 1-10V line on the back of the profilux and the ballast AC plugs into the power bar.
WARNING - DO NOT plug the
"Dimmable" power bar into an "S" socket on the ProfiLux, seriously - Don't
The beauty of these ballasts is
1. Far less wiring
2. Available in all wattages in 110V