Wiring a DCS and Legacy Layout

You can use the variable outputs on the TIU to control tracks with conventional engines. Technically, you can operate command locomotives independently on the same tracks, BUT the top speed of the command locomotives will be limited by the voltage you're controlling the conventional locos with.

Also, under such an arrangement the command locos will stop and/or possibly misbehave when you cycle power to operate the conventional units' reverse units. It's best to keep command and conventional on separate loops, isolated at least by insulating pins on the center rails on any connecting tracks.

An AIU is an accessory controller, I don't believe it has anything to do with conventional trains.

As for your eight blocks, placing insulating pins on the center rail between power feeds will prevent DCS locos from getting overlapping signals coming from the multiple feeds, and the Legacy/TMCC signal can be fed to and coexist with any track carrying a DCS signal.

---PCJ

My Run Room is wired as you describe with Buss Wiring .  That page of my website is a start.  My track is fed through 4 MTH DCS TIUs or transformers controlling the track. Toggle switches control power source to track.

Please feel free to email me with specific questions.