Can I run TMCC, Legacy, and DCS systems together without linking them thru the DCS system.

Yes you can, only one TIU would be needed - just set the var tracks to fixed to run four command tracks.

@hclark6345 posted:

I know this would require separate hand controllers for each system, but that is a plus for me because I like using separate controllers for each engine.

As long as you're ok with this you'll be fine, largely.  I say largely because some TMCC/Legacy locomotives and rolling stock, when running on a track segment carrying the DCS signal, can tramp it down.  There's a fix involving inserting a choke (an inductor, 22 uH) inside the loco or car, spliced into the power lead coming from the center rail pickup.

Mike

BTW -- Find your copy of Barry's book.  You'll be glad you did if you have to debug anything DCS-related.

Darrell and Mike

Thank you for your quick replies.

Darrell

Using the variable outputs for fixed also simplifies things.

Mike

would using a choke on each TIU output help with the signal loss.

And yes, I am searching for the book. It will eventually turn up.

Thanks

Howard

@hclark6345 posted:

would using a choke on each TIU output help with the signal loss.

Actually, putting the 22uh inductor on each TIU output would totally kill the DCS signal to all the tracks!   The inductor blocks the DCS signal, exactly the opposite of what you want to do!

You put them on the TMCC/Legacy engines if necessary to prevent the internal electronics of the TMCC/Legacy engine from affecting the DCS signal.

Just curious. Why would you want to do that and not just hook the systems through the DCS?

@John C. posted:

Just curious. Why would you want to do that and not just hook the systems through the DCS?

John,

Do you mean:

1.) Hook the systems through the DCS?

   or

2.) Run the systems only using the DCS handheld remote?

Mike

@John C. posted:

Just curious. Why would you want to do that and not just hook the systems through the DCS?

Maybe he's like me and would much rather run with the Lionel remote than put up with the flaky thumbwheel on the DCS remote?

You can run Legacy using Cab2 and MTH using DCS handheld.  In fact, you can run them on the same track at the same time.  I operate that way frequently.  I use the quick speed feature to minimize thumb wheel use.  Hope that helps.

You didn't state the size of the layout or if you have more than one loop. If you have just one loop with 4 power districts only one TIU channel is needed, you would just use a distribution block to split the output to the power districts.

Darrell
I am running four separate loops so I will need four separate channels so I can control a different train  on each loop. ( I am not coordinated enough to do them myself all at once, but when I have grandkids over it will be possible )
Thanks
Howard

One TIU channel can control multiple trains, we're not talking conventional operation here.

John

I am also talking conventional operation. I have several conventional engines and I want to be able to control them individually in each power district. That’s why I wanted 4 TIU channels, to keep my districts separate so I can run conventionally. or DCS if I want to. I plan one wire to the track for TMCC, another wire to the track for Legacy.

I thought I needed a TIU channel for each separate district, to keep my ability to run each channel effectively as a conventional control district thru the transformer handle

I did not think that the DCS signal would jump across power districts. If it does, I can just run one district thru a TIU, but still control engines in other districts with those 3 districts wired direct to the transformer and only the one district running thru a TIU channel. With DCS available in those 3 districts if desired even if they are not run thru a TIU channel. I didn’t think that will work.

There, hows that for a convoluted explanation

Yep, easier to just run one channel per loop, you can then have 4 little engineers running 4 conventional loco's. If you have Legacy you don't need a wire for TMCC, just run them with the Legacy. I have 2 loops with DCS, I connect the wire from the Legacy base to the output post of the TIU for the inside loop and can run all my TMCC loco's on both loops with no issues.

@hclark6345 posted:

John

I am also talking conventional operation. I have several conventional engines and I want to be able to control them individually in each power district. That’s why I wanted 4 TIU channels, to keep my districts separate so I can run conventionally. or DCS if I want to. I plan one wire to the track for TMCC, another wire to the track for Legacy.

Note that only two of the TIU channels have variable voltage, the other two are fixed voltage channels.

Another thing that I didn’t see mentioned is you can also run one TIU in passive mode. This will put the DCS signal on the track without running the current from the transformer through the TIU. This does come with some caveat the emergency stop button will no longer work as the TIU can’t kill power. Also, inside the TIU it typically and cleans up and coming power via a choke without that now that’ll hamper down the DCS. The fix is to put a coke before adding in the DCS signal. I did this with my clubs new layout so I made a PCB to hold a choke and a TVS diode. I realize it’s not an ideal TVS location but it’s there.

if anyone is interested in these my email is in my profile I made some new ones that also have the simple DCS tester incorporated just because I like blinking lights 😜

Candidly, in terms of command control, I would make Legacy/TMCC the backbone of my command control system.  Legacy/TMCC is a more reliable, less fussy command control interface than DCS.  Both the hardware and how the system works is pretty bulletproof.  I also use Legacy/TMCC Powermasters to have variable voltage on both tracks, so I can both fine tune the voltage to avoid bulb burnouts on the older cars that lack LEDs, and so that I can run conventional/postwar equipment.  I also use the Powermasters on the accessory channels so that operating accessories can also be tuned for voltage and to reduce bulb burnout.  180 watt Powerhouses for each of the tracks also provides plenty of power and the circuit breakers are very fast / sensitive.  I also installed TVSs across all of the power drops.  

Before the DCS fans come with the pitchforks, we run DCS too, but I run it in passive mode.  

I love MTH equipment and generally have found their mechanicals to be more robust than Lionel (and even Williams, who can sometimes ruin a nice locomotive with a cheap detail on the mechanicals), but using DCS in passive mode gives you all the features of DCS but doesn't leave you overly reliant on it as it can be fussy when adding locomotives and with track signals generally.  I have run both systems together this way for about 10 years, and I generally am OK, with only the occasional outbreak of DCS related problems that can usually be addressed with simple troubleshooting.  

Finally, alot of the fellas posting above are more advanced than I am with electronics.  When programing a DCS locomotive, or having any issues with a DCS locomotive, the simple and generally foolproof approach to resolving the issue involves removing all other DCS and Lionel TMCC/Legacy locomotives from the tracks.  You can install chokes and what-not but I am not comfortable with that type of electronic related work.  Yes, their solution is more elegant, but my layout isn't that big and I can reach and grab a locomotive pretty easily.

In sum, I say keep the systems separate and keep it simple.  Good luck!  

@gunrunnerjohn posted:

Note that only two of the TIU channels have variable voltage, the other two are fixed voltage channels.

As I posted earlier the solution for him is to set the variable channels to fix voltage, easy enough to do. That also keeps it simple for him since he wants to control with transformer handle anyway when running conventional.

@Mellow Hudson Mike posted:

John,

Do you mean:

1.) Hook the systems through the DCS?

   or

2.) Run the systems only using the DCS handheld remote?

Mike

Hook the systems through the DCS