DCS & Legacy on Modular Layout

John,

 

To muddy the waters for you, is any equipment on the layout other than the one MTH engine? We've had minor issues with a certain MTH engine (and not others) depending upon what is running.

John,  I have been having the same issue and my layout is smaller.  I been checking track connections and wiring. It seems that in the last two weeks there have been a lot of posts concerning this issue. I starting to wonder if it is an issue with the TIU. I replaced mine about two months ago. This one has 4.30. I powered down my TMCC base but still have the issue. Thought I had it resolved but after a day, the issue returned.

Bobby, nothing on the layout but the one MTH locomotive when we do the test.  The only variable is the power applied to the Legacy base.

 

suzukovich, your problem appears to be slightly different, as soon as we remove power from the Legacy base or disconnect the track wire, the problem is gone.

Is the 9 pin being used to connect the 2 systems?  If so, I seem to recall the original TMCC cable that MTH put out did cause issues when used with the Legacy base.

We don't connect the two systems.  The only connections to the Legacy base are the power and the track wire.

 

I had a weird issue where I wouldnt get any legacy signal unless I put the Legacy signal wire on the input of the TIU. Every time I look at the TIU's with the legacy signal wire on the input it drives me nuts since this defys my convention but it doesnt work the other way

Have you tried another base, power supply, and DCS system in case one of those components have an issue?

 

I imagine you probably have but...

Is it possible to plug the legacy base into a completely  different wall outlet circuit?

 

Does the TMCC base do the same thing? (if you have one)

Matt, our Legacy signal is fine without or without the DCS connected, it's the DCS signal that gets nuked when we power up the Legacy base.

 

Marty, The same thing has happened with three different Legacy bases. I have not tried an old TMCC base, it's probably worth a shot, though most folks have Legacy CAB2 remotes, so that would be a problem.

 

I haven't tried the Legacy base on a different outlet, but since the DCS has no direct coupling to the power line or earth ground, I don't have high hopes for that changing things.  I may try that tonight anyway, just to see what happens.  I might also connect the Legacy at the opposite side of the layout as a test, though again I don't see this as a high probability solution.

 

I've been thinking of adding the 22uh RF choke in series with the Legacy lead to the track to see if that has any effect.  I'm also going to try a series capacitor to see if there is any DC shift or other coupled voltage that might be causing an issue.  These are really a "shot in the dark" to see if I can affect the issue positive or negative.  Finally, I'm thinking of a low-pass filter to damp any 3.27mhz signal while letting the 455khz through on the Legacy track connection.

 

 

 

Hopefully someone from Capitol Cities or Pittsburgh Hi Railers will chime in. I think both of them run DCS and Legacy on their big layouts. There hasn't been enough interest in my club to attempt rewiring for DCS so I can't help here. Its a major challenge though, especially if the layout configuration changes every show.

 

Pete

I know, but there can be strange things afoot when DCS is involved

Where do you connect the legacy signal at?

Try moving it furthest away from the point where you connect the DCS at. I believe you can add the Legacy signal anywhere right? It worked in two rail anyways. It still affected it, just a little better result.

 I'm going to add it someday when I get the patience. I thought it was worse in two rail? I will probably just have it on it's own tracks.

I wish the archives went back further... If I remember correctly this issue came up when legacy first came out.   Don't rule out a different wall outlet just yet. (I know you haven't)

I'm going to try all of those, I'd like to get this working and understand why it doesn't work.  I'm calculating some low pass filters now for that test.

 

Hi John!

 

I run both DCS and Legacy on my layout, run trains under both control systems simultaneously, and have never had any issues. I have no clue as to what the DCS signal strength is, but the DCS locos run fine.

 

I get the occasional 'Engine not on Track' and similar messages when I have not run a DCS engine for a while, but have always been able to resolve the issue promptly. At worse, I have deleted and re-added the problem loco. But again, this happens infrequently. Once the locoes are recognized, they run fine. 

 

Legacy locos, on the other hand, NEVER fail to run fine 100% of the time. 

 

I have two TIU's connected to eight relay distribution modules, connected to 48 districts and tracks blocks. The Legacy base is connected with its one wire to the outside rail. My layout has over 900 feet of track and 57 turnouts.

 

Good luck!

 

Alex

 

PS. I had one issue with the Legacy early on. Some Legacy locos were not responsive in one stretch of about six feet of track where the second level was right over it. I solved this by adding a ground wire between the upper and lower levels. The ground wire is connected directly an outlet ground. Funny thing is that I have about 200 feet of track in the lower level under the upper level track, but only six feet had a problem.

It's a mystery Alex, the Legacy kills the DCS track signal dead!  I hope I can chase it down, I'm sick of not being able to run both on the club layout at the same time.

 

Have you tried isolating sections of the layout to see if there is an oddity in a module causing an issue?

When we were resolving the DCS issues, we worked our way around the layout sorting out signal issues as we went.  Now that were done with that process, I get 9's and 10's all around the whole setup on both tracks.  This is a bus wired setup as is pretty mandatory with a modular layout.  The only thing we do is connect the Legacy and the DCS goes in the tank.  I suppose anything's possible, but I really think trying to attack it that way is probably a very low percentage play.

 

 

It was just a thought beings you have tried a lot of other things.  The problem maybe easier to isolate on a smaller section of a layout than large.

I would be willing to be the solution is much simpler than the problem

The National Capital Trackers went away from the old school shared common wiring to each main having its own common (return) wire. This alone eliminated most DCS issues. On Tracker layouts the TMCC/Legacy signal is feed at the black terminal posts on the OUTPUT side of the TIU. We do not see signal degradation from Legacy.

 

Steve

Volkswagon secretly added software to their diesel engine cars to trick emissions test.

Soooo, maybe Lionel has a secret chip that when sensing DCS it cuts power?  Just kidding!

Guns,

   Although my Christmas layouts are not modular engineering, I did have the same problem, I corrected the problem by using Marty F's suggestion of running the Legacy thru the Black TIU Channel and also connecting the Legacy 990 base directly to the opposite outside rail of the DCS connection.  Using both outside rails eliminated all my Legacy Problems, as long as I have the Legacy Base plugged directly into a properly grounded wall outlet.

PCRR/Dave

This is what I have been trying to get the FCTT HiRailers to do, separate commons for each mainline but it would mean modifying some 150 plus mods and I seem the only one interested in DCS.

 

Pete

I don't know why I'm posting this but if the "U"connection on the  legacy base   is left disconnected (not hooked up to track)  with the base powered up , does the dcs signal still go south?  Could the base alone be causing the problem?

This is what I have been trying to get the FCTT HiRailers to do, separate commons for each mainline but it would mean modifying some 150 plus mods and I seem the only one interested in DCS.

 

It took two years of research, canvassing, and extolling the virtues before our board approved and then the membership approved the change by an overwhelming majority. Now that it has been done, nobody has said I wish we had the old wiring, in fact a couple of the naysayers have recognized the improved results.

 

Steve

The problem goes away if we either disconnect the Legacy track connection or power down the Legacy base.  It clearly seems associated with the presence of the Legacy signal on the track.

 

We actually have plans to change the grounding of each mainline.  We have the earth ground running in the same plug with #12 wire as everything else.  I want to separate the earth ground and use that #12 wire for a second common for the second mainline  The earth ground will be separated for the other wire bundle and run with lighter gauge wire as it doesn't have to be a current carrying conductor.  Obviously, that's going to take longer than we have to get this running for the Christmas show, we are open on the 5th for the first display.

 

I'm going to proceed with my filtering attempts to see what happens.  I have a feeling that I'm spinning my wheels, but I want to try a few things tonight and see where they go.

 

FWIW, we feed the track signal about two feet from the output of the TIU channel ground, I doubt moving it to the TIU will radically change this behavior.

John,

 

Our TMCC/Legacy reference wire is in the same bundle and connector as the rest of the main bus wiring. The one thing it doesn't do is break out in the terminal block. In the dark ages when we attempted to make things work we installed filters everywhere, results varied. The engineering analysis on the new harness showed the filters (as well as twisted pair) to impede DCS signal.

 

Steve

Well, the only way we got decent DCS was with a bunch of filters, but the Legacy issue was with us before we had filters and still with us.  Without the Legacy connected and/or on, DCS works great!  I'm at a loss as to why Legacy has such an impact on the DCS signal.  Since it's clearly some sort of interference, that's why I'm looking so hard at knocking down the higher frequencies with either the choke or a low-pass filter.  The series capacitor is just a Hail Mary for grins, I don't seriously expect it to have an effect, but I've been surprised before.

Our modular layout has two mains with one fixed TIU channel dedicated to each main. Each main has separate commons but these get interconnected at the yard. The layout is not wired in a star pattern. We have a Rev L TIU and a Cab1L base and have no problems with either the DCS signal or the Legacy signal. I don't know how much or even if there is a difference between the 1L base signal and the Legacy signal.

 

What Rev TIU are you using?

What are you using to power the tracks?

 

Ken

Might have missed this above, but didn't see it mentioned? You are way ahead of me on all this anyway, but as a long shot have you tried a different TIU, preferably a Rev L? Adding more DCS blocks is probably not an option? Wish I had something I could help you out with here.

 

I have a much smaller layout that hasn't had any Legacy or DCS problems so far (fingers crossed). It has all worked very well since it was permanently set up last year, so I have not seen this problem. 

 

FWIW, It's wired for DCS as closely as possible to the 'DCS Bible', then the Legacy wire was connected to all the TIU outputs in use (only using two channels), all Atlas track and switches. 

Way out of my league - I have TMCC and the basic DCS Remote Commander.

 

I have run PS2 and TMCC (actual Lionel die-cast steamer) on the same track at the same time.

 

When I put some TMCC (typically brass upgrades) locos on the same track with the same

PS2 loco, all of a sudden the PS2 loco loses its grip on command and accepts no orders.

Just keeps running until I cut the power.

 

Not helpful, I'm sure. Never have investigated it much; I'm a TMCC/Legacy loco runner anyway, 90% of the time.

 

It just works.

 

Actually, we gave up trying to get DCS to work on our layouts years ago.  We run our MTH equipment in conventional mode controlled with Legacy/TMCC remotes by way of the ZW-L.  Even though some of our guys have lots of MTH engines, there is little to no interest in re-wiring the 100+ modules owned by the various club members.

 

Andy

Hopefully it can be solved to night John
I would  like  See it work.
It's a bummer when the guy's that have the MTH engines and can't run.
I do feel bad for them.
Then maybe we can get it working on the main layout.
It is a bummer when I tell a guy sorry you got to wait till the Lionel guy's are done running. 
See you tonight.

At one point we had filters on every nearly every module and each module had a filter on every track. I made over 200 of those things. MTH DCS equipped engines certainly performed better than they would have without them. We tried all kinds of tricks, insulating pins between modules, layout fed in blocks,etc. The difficulty at least for  the Trackers is that we seldom build the same layout twice so it is hard to tune. Things like star pattern wiring lend themselves to fixed layouts, not so much with modular ones. With our new harness (April York 2014) DCS works. The biggest issue we see now is the 900Mhz Remote to TIU interference, but the trains run, and run well.

 

Steve

"I haven't tried the Legacy base on a different outlet, but since the DCS has no direct coupling to the power line or earth ground, I don't have high hopes for that changing things.  I may try that tonight anyway, just to see what happens.  I might also connect the Legacy at the opposite side of the layout as a test, though again I don't see this as a high probability solution."

 

I would guess that using a separate outlet, or even more importantly, keeping the Legacy base at the far side of the layout from the TIU is a good possible fix.  There are mysterious ways in which the proximity of two different radio frequency antennas detune each others' signals. 

The Trackers have always had issues when attempting to operate off of multiple outlets. Your mileage may vary, but it is easy to end up on different phase. In our current power cabinets the Legacy base and the TIU are within 6" of each other. I do remember a show where we had a long layout about 100' that had TMCC issues. the base was moved from the middle to an end with no improvement to either system. This of course was only a single try and no additional attempt was made at science to improve it. Prior to having power cabinets, all transformers and control systems were generally installed at one central module to the layout.

 

Steve

I'll second this. When the Independent Hi-Railers, Midwest Division was still active, we learned the hard way to use ONLY ONE outlet in the building we were displaying/operating in, for powering EVERYTHING. One of our members worked for Comed, in Illinois, and made a special, VERY heavy-duty multiple outlet, power distribution box, which was thus plugged into one single outlet in the building.

We are using Rev. L TIU's and Lionel PowerHouse 180 bricks for power.  I have build myself a Chebyshev low-pass filter with a cutoff frequency of 455khz for the Legacy signal.  It passes the Legacy signal just fine, but at 3mhz, the output is down almost 30db.  I connect that referenced to earth ground and in the TMCC track feed, I'm going to try that tonight.  Yesterday we were testing both active and passive mode connection for the TIU.  I noted that passive mode didn't work as well, so I also created a bunch of cables to change over to active mode for the TIU.  Hopefully that combo will yield some positive results.

 

From all the comments from various clubs I've talked to, we're not the only folks that have issues getting DCS to run on a modular layout. 

 

To be continued.