John, thanks for the toggle explanation.You're right in that the TIU is already powered when I flip the switch. I park engines that way so they don't accumulate hours just sitting. I have no DCS problems that I know of with the MRC transformer. I just put the TIU in after the transformer leads and everything works well. My Remote Commander never did, though. I have 7 sidings on toggles and 5 blocks with a low signal in a couple places but never any response problems. I am moving to a new 20X30 addition to the garage from the attic where I can only stand up in the center. I'll probably find problems when I try to do everything right.
John