I wired the master power for my EFIS to my VP-50 control unit and ran the grounds for the unit and remote compass to the avionics ground bus then hooked up the EDC-10 remote compass. I inserted my Dynon D100 EFIS into the cutout (the mounting tray is on back order), turned on the battery master and the avionics switch and presto; it worked! The unit detected the compass and displayed the correct heading. Very cool. I entered the local magnetic inclination and intensity and played around with the menu items. There are still a few sensors that aren't installed yet, like the OAT, A of A and GPS (which will display the CDI on the HSI).