Do you need power going to the switch portion (line voltage on Black lead) to control dimming on the IP710 and DS710?
No. The switch and dimming circuit are completely separate within our devices. The 0-10V dimming circuit will still provide a dimming signal to the ballast/driver even without line power. This wiring is generally applicable with the use of a power pack (OPP20), and potentially a larger lighting system including additional 0-10V sensors.