Track Occupancy Detection on a DCS Layout

I don't have detection circuitry on mine, but when I added Legacy to my DCS system I jumpered all the AC common TIU outputs together and connected the Legacy signal at the TIU. Works just fine. Don't see why you could not do the same with the detection circuits? That idea came either from Barry's book or someone here on the forum (wasn't originally my idea).

I have a Rev L TIU and the output commons are separate. I think they were all common on some earlier TIU models?

My friend's understanding is that DCS doesn't have a single AC common, rather each TIU channel is a separate common which is not connected to other TIU channels.  Is that correct?  Would we need separate DC transformers for tracks connected to separate TIU channels in that case?

Hopefully someone with a DCS layout uses track occupancy detection for signals or something else and can help us out.

Thanks in advance.

Hi Bob.....We're operating with 4 tiu in super with 8 PWZWs. All the U connections are tied together on the transformers  and therefore all the tiu commons are  tied  together via the U connections and also the track.

I don't why  you couldn't  use   DC- imposed on the AC  common for  DC relays  & leds.

 Still have the (Weaver)  Mikado you purchased from me years ago... Bob  gave me quite a bit more than  the asking price because I didn't know any better....  that's  something I 'll never forget.

You can use the insulated track technique with DCS the same as with TMCC/Legacy, the same signaling system will work fine for either.  The signal switching is just switching the ground, that's common for all your track.

All TIU commons (black terminals) should be tied together externally (Only Rev G had the 4 blacks tied internally).  Note that trains crossing from one circuit to another will connect them momentarily even if you used fiber pins in outside rails to keep them separate.

Thanks to all for the helpful replies.  This is just what we need to know!