I agree with J Daddy and Joe. My layout is 14x14 and is wired the same way I use to wire for conventional; one transformer handle to one loop with power drops. The loops are connected but the center rail is isolated. When I added DCS I just inserted the TIU between the track loops and the transformer. I attached the Legacy wire to one of the grounds on the TIU output side. I set all TIU channels to fixed and powered the TIU with a wall wart.
Basically, if your Legacy system is working well, DCS will work as well. You should not need to rewire anything beyond inserting the TIU into it.
One caveat, you did not indicate the size of your layout. I understand that as your layout gets larger you may have DCS signal issues which require modifications to your wiring. I have never had the luxury of too much space, so I can’t speak to this problem.
If you go with DCS get a copy of Barry’s book, it is a great help.
