Gilly & rtr12,
Now that you guys are using the TIU TR mode, there is another TR mode that runs thru the Z4K side receiver, this allows for even more conventional trains to be run at the same time, another cool way to run your older conventional trains from the DCS hand held remote control, and the old engines run smoother in this TR Z4K mode than they do from a standard conventional transformer. You must have the side receiver hooked to your Z4K to run in this manner however. If you have a Z4K invest in the side receiver, it opens up another cool running option.
PCRR/Dave