There are two variable channels and two fixed channels on the TIU. You can run conventional equipment using the DCS remote when powered by either of the variable channels of the TIU. For tracks powered by the fixed channels, you can run conventional if you have a variable voltage transformer powering that channel.
Power goes through the TIU from the input side to the output side, and you can power one or more channels from a single transformer, or each channel from a separate transformer output. Mine is fairly simple, four transformers, each powering one of the inputs of the TIU. Obviously, two of the loops can only run command with my setup, but the mainline and sidings have variable voltage control from the DCS remote with this configuration.
