I have a Gaugemaster (MRC) Prodigy 2 and what I did was to make a virtual ground using 2 diodes on the track output of the Prodigy, feeding into the then feed them into a 1k? resistor.? For the railsync signal which is required for the BDL 168s? as I was worried about the 15V output going into the 7v no 1 pin (White on a loconet cable) on loconet, I put another 1k resistor in the non return leg of the Prodigy. I now have a DCS 50 Zephyr running as a master for track detection and the Prodigy for loco control and the system works well. The link for the railsync is here?
and the virtual ground link is here.
SwissChris