Re: Transponder key settings
Opencockpits sell A320 & 737 transponders, both p&p. no programming required.
Re: Transponder key settings
I'm not sure if this will help, but I believe there is a list of offsets in the FSUIPC directory.
Re: Transponder key settings
I dont know if its compatable with VOXATC, but I interfaced a real F-4 Phantom Transponder to use with Pilot Edge online ATC. You are correct there is not an IDENT function in FSUIPC. When I installed the pilot edge software the SB3 install added the Ident function to the FSUIPC list. For online flying I only use SB3 Transponder and transmit Offsets, not the default FSUIPC offsets.
Re: Transponder key settings
Also, the default FSUIPC transponder offset are labled Xponder, so look at the x section of the programing list. I assume you are using buttons or keys and assigning them to a function in the FSUIPC user interface.