Steve fixed the issue with the XPDR. It now appears functional although I have not transmitted with it yet. The fix was contained in v3 firmware for the Flightbox Pro. However, it broke the Trig COMM radio data stream on the TMAP bus, displaying random COMM frequencies. He is working on many upgrades including:
Separate USB cables for each Trig radio, separating TMAP data communications.
I guess this is the reason Steve has not posted much recently. Sounds like he has been busy with this and other issues. Do you have the TruTrak autopilot also? I have the Trig transponder and the cable but have not yet wired it into my Flightview system. Are using the control head for the xpndr and also the flightview interface or do just operate the transponder blind, with no TC20 control head? I am reluctant to hook up my xpndr without the control head also functional.