Date   
Re: Reversing loop with multiple trains in the loop

redking56@...
 

That's a great point, Steve. It is why I always refer to the affected track as the "reversing section". The common terminology of "reverse loop" is too limited in its application and, often, the reversing section is not necessarily a loop at all.

Rich


---In WiringForDCC@..., <Goatfisher2@...> wrote :


Ed, please follow up with Don's request and provide us with a track plan for our review.

One of the biggest myths in model railroading is the track that physically reverses the train _must_ also be the section of track that is electrically reversed. Nothing could be further from the truth!

www.wiringforddc.com has several examples where the track that creates the need for a reversing section is _NOT_ the section of track that is wired for reversing. One example is a wye added to a mainline loop. The wye in these example typically feeds a yard ( this configuration is often used by module groups - a yard in the middle of the looped of modules, connected to the loops via a wye). If either leg of the wye is used as the reversing section, and the train length limited to the length of one leg of the wye, you run into the problem of train length limited by the size of the leg of the wye problem. Move the electrically reversed section to a one train length section of thmain loop, , one train length long, including the turnout at that segment of the wye, and the train length issue is solved!


best regards,
Steve haas
On the road in Antioch, IL

Re: Reversing loop with multiple trains in the loop

Steve Haas
 

Don Vollrath wrote:


Ed, Post a photo or file with a sketch of your track plan so we can learn more about the short train issue. there has got to be a better plan.
Ed, please follow up with Don's request and provide us with a track plan for our review.

One of the biggest myths in model railroading is the track that physically reverses the train _must_ also be the section of track that is electrically reversed. Nothing could be further from the truth!

www.wiringforddc.com has several examples where the track that creates the need for a reversing section is _NOT_ the section of track that is wired for reversing. One example is a wye added to a mainline loop. The wye in these example typically feeds a yard ( this configuration is often used by module groups - a yard in the middle of the looped of modules, connected to the loops via a wye). If either leg of the wye is used as the reversing section, and the train length limited to the length of one leg of the wye, you run into the problem of train length limited by the size of the leg of the wye problem. Move the electrically reversed section to a one train length section of thmain loop, , one train length long, including the turnout at that segment of the wye, and the train length issue is solved!


best regards,
Steve haas
On the road in Antioch, IL

Re: Detecting engine's DCC address

Mark Cartwright
 

In a word Yes.
I own several different DCC Controllers, nearly all purchased (cheap) > as a possible later re-sell...if I found them wanting.
Two MRC, Two Digitrax, Dynamis and ??? More.
Yet.... I nearly had to fall over one of these...Before I gave it a try.
Sorry about the funny way some of these gentlemen speak and the way they explain things...
Cause...
It's better in German 
===
If you are using LokSound Decoders...The ECoS may immediately recognize it's own...and place it in your inventory. That is if you are not fooling around attempting to recognize it via it's cab number.
Oops!
Then show it in routing. Go with their way of doing things....and you will begin to discover more.
Here's an American Voice...
Also works extremely well with Kato Unitrack and a Digitrax DS-64 but ESU also makes their own.
which work very well with their Servo Motors for other types of turnouts.
====
Note how this last poster is setting his Servo and turnout to it's own base.
I am as of now in an attempt to do something similar with #10 and #12 N Scale Turnouts, attached to 1960's era HO/S Scale and re-whittled Tru-Scale Wooden Bases.
=====
Be careful what you wish for....It might actually exist.
You may have to work of it however.
What the ?!?!? is this guy doing at 1:09 
and is all that necessary?
What's that Bunny doing out of his Box ! - Nicholas Cage
=====
Watch a few dozen of these You Tube Videos...and you will have barely scratched the surface on what one of these ECoS Controllers can do.
They make ESU LokSound decoders sound better and do more as well, with less loss of signal (Decoder Reset). Problem is..They make you want to be a better Model Railroader. Sort of like going out with a Better Woman...Makes you want to be a Better Man.
Translating German can be very tiring, even with 2 years of High School German and two years at University. I love You Tube.
Mark

Want to see an explanation in annoying French?
Watch what I can do with my little stick. (then drops it) at 0.50)
Big Talk for a guy with an undersized Eiffel Tower on his layout. LOL

Re: Reversing loop with multiple trains in the loop

dvollrath@...
 


Ed, Post a photo or file with a sketch of your track plan so we can learn more about the short train issue. there has got to be a better plan.

DonV

---In WiringForDCC@..., <ed_sargent@...> wrote :

It is the train length rule that has caused us to redesign a section or limit the layout to three car trains (including the caboose)

  

Re: Detecting engine's DCC address

whmvd
 

And there's RFID detection.

On 28 June 2017 at 04:01, Mark Gurries gurriesm@... [WiringForDCC] <WiringForDCC@...> wrote:
 

The other method is Lenz RailCom.


This and Transponding are the only two systems and respective primary DCC system vendors.  There are a few 3rd party DCC vendors which support one or the other.

Transponding has been most successful in the US where as RailCom is primarily European.

The NMRA has approved a version of RailCom but it is an "optional standard" which means implementing it is not required.

Both system require special or additional equipment to work both on the decoder side and the layout side.

On Jun 27, 2017, at 7:22 PM, 'Paul O' pomilian@... [WiringForDCC] <WiringForDCC@...> wrote:



Ed, Yes, with Digitraxx ‘Transponding’.
Search the Digitraxx website for more info.
 
Paul O
From: WiringForDCC@yahoogroups.com [mailto:WiringForDCC@...] 
Sent: Tuesday, June 27, 2017 1:50 AM
To: WiringForDCC@yahoogroups.com
Subject: [WiringForDCC] Detecting engine's DCC address
 
  

Is there a way to tell what specific engine or consist is in a block?


Posted by: ed_sargent@...



Best Regards,

Mark Gurries
Electrical Engineer
DCC Website & NMRA DCC Clinics: www.markgurries.com




Re: Detecting engine's DCC address

Edward Sargent
 

Pity, the only Digitrax decoders we have are on engines with no sound, besides that we are NCE.

 

Has anyone used the CTI RFI detectors? Maybe those will work?

 

From: WiringForDCC@... [mailto:WiringForDCC@...]
Sent: Tuesday, June 27, 2017 9:02 PM
To: WiringForDCC@...
Subject: Re: [WiringForDCC] Detecting engine's DCC address

 

 

The other method is Lenz RailCom.

 

This and Transponding are the only two systems and respective primary DCC system vendors.  There are a few 3rd party DCC vendors which support one or the other.

 

Transponding has been most successful in the US where as RailCom is primarily European.

 

The NMRA has approved a version of RailCom but it is an "optional standard" which means implementing it is not required.

 

Both system require special or additional equipment to work both on the decoder side and the layout side.

 

On Jun 27, 2017, at 7:22 PM, 'Paul O' pomilian@... [WiringForDCC] <WiringForDCC@...> wrote:

 



Ed, Yes, with Digitraxx ‘Transponding’.

Search the Digitraxx website for more info.

 

Paul O

From: WiringForDCC@... [mailto:WiringForDCC@...] 
Sent: Tuesday, June 27, 2017 1:50 AM
To: WiringForDCC@...
Subject: [WiringForDCC] Detecting engine's DCC address

 

  

Is there a way to tell what specific engine or consist is in a block?


Posted by: ed_sargent@...



 

Best Regards,

 

Mark Gurries

Electrical Engineer

DCC Website & NMRA DCC Clinics: www.markgurries.com

 

 

 

Re: Detecting engine's DCC address

Mark Gurries
 

The other method is Lenz RailCom.

This and Transponding are the only two systems and respective primary DCC system vendors.  There are a few 3rd party DCC vendors which support one or the other.

Transponding has been most successful in the US where as RailCom is primarily European.

The NMRA has approved a version of RailCom but it is an "optional standard" which means implementing it is not required.

Both system require special or additional equipment to work both on the decoder side and the layout side.

On Jun 27, 2017, at 7:22 PM, 'Paul O' pomilian@... [WiringForDCC] <WiringForDCC@...> wrote:



Ed, Yes, with Digitraxx ‘Transponding’.
Search the Digitraxx website for more info.
 
Paul O
From: WiringForDCC@... [mailto:WiringForDCC@...] 
Sent: Tuesday, June 27, 2017 1:50 AM
To: WiringForDCC@...
Subject: [WiringForDCC] Detecting engine's DCC address
 
  

Is there a way to tell what specific engine or consist is in a block?


Posted by: ed_sargent@...



Best Regards,

Mark Gurries
Electrical Engineer
DCC Website & NMRA DCC Clinics: www.markgurries.com



Re: Detecting engine's DCC address

David Heine
 

Besides Digitrax Transponding, which, as far as I know is only supported by Digitrax, you can use Railcom, which is supported by several manufacturers, mostly the European ones. Zimo also had their own system loco ID system for years, but their new system seems to be set up to use Railcom.

In all cases, you need decoders that support the chosen system plus the required system equipment.

Dave Heine
Easton, PA


On Tue, Jun 27, 2017 at 10:22 PM, 'Paul O' pomilian@... [WiringForDCC] <WiringForDCC@...> wrote:


Ed, Yes, with Digitraxx ‘Transponding’.

Search the Digitraxx website for more info.

 

Paul O

From: WiringForDCC@... [mailto:WiringForDCC@yahoogroups.com]
Sent: Tuesday, June 27, 2017 1:50 AM
To: WiringForDCC@...
Subject: [WiringForDCC] Detecting engine's DCC address

 

 

Is there a way to tell what specific engine or consist is in a block?


Posted by: ed_sargent@...




Re: Detecting engine's DCC address

Paul O
 

Ed, Yes, with Digitraxx ‘Transponding’.

Search the Digitraxx website for more info.

 

Paul O

From: WiringForDCC@... [mailto:WiringForDCC@...]
Sent: Tuesday, June 27, 2017 1:50 AM
To: WiringForDCC@...
Subject: [WiringForDCC] Detecting engine's DCC address

 

 

Is there a way to tell what specific engine or consist is in a block?


Posted by: ed_sargent@...

Detecting engine's DCC address

Edward Sargent
 

Is there a way to tell what specific engine or consist is in a block?

Re: Reversing loop with multiple trains in the loop

Edward Sargent
 

It is the train length rule that has caused us to redesign a section or limit the layout to three car trains (including the caboose)

 

From: WiringForDCC@... [mailto:WiringForDCC@...]
Sent: Monday, June 26, 2017 7:46 PM
To: WiringForDCC@...
Subject: RE: [WiringForDCC] Reversing loop with multiple trains in the loop

 

 

 



The section of tack that somehow causes a train to change directions on mainline tracks, is the only part that changes in electrical polarity. An Auto-Reverser like device will always flip the polarity to match that of mainline tracks at one end or the other as a train enters and/or exits the Auto-Reversing section of track. All other mainline tracks remain at a fixed polarity as wired to the booster. This is the main reason that the A-R section of track should be longer than any train, as it should not be attempting to exit while cars with steel wheels are still entering at the other end. [Maximum train length is kind of obvious if it is a simple balloon loop fed by a single turnout.] 

   

DonV

 

 ---In WiringForDCC@..., <ed_sargent@...> wrote :

Perfect, that is what was missing from my understanding. Nothing I have read pointed out exactly what was reversed, the section the train was leaving or entering.

  

Re: Reversing loop with multiple trains in the loop

dvollrath@...
 




The section of tack that somehow causes a train to change directions on mainline tracks, is the only part that changes in electrical polarity. An Auto-Reverser like device will always flip the polarity to match that of mainline tracks at one end or the other as a train enters and/or exits the Auto-Reversing section of track. All other mainline tracks remain at a fixed polarity as wired to the booster. This is the main reason that the A-R section of track should be longer than any train, as it should not be attempting to exit while cars with steel wheels are still entering at the other end. [Maximum train length is kind of obvious if it is a simple balloon loop fed by a single turnout.] 
   
DonV

 ---In WiringForDCC@..., <ed_sargent@...> wrote :

Perfect, that is what was missing from my understanding. Nothing I have read pointed out exactly what was reversed, the section the train was leaving or entering.

  

Re: Reversing loop with multiple trains in the loop

Blair & Rasa
 

Ed,

Apologies to all, but particularly you. Somehow (I've been messing with my sorting rules, or someone has) I had messages from both the Digitrax list and the WiringforDCC list cross-pollinating in respective folders for about 48 hours, hence my confusion; what a mess.

My explanation, fortunately, wasn't contaminated with my confusion. O'scopes are uncommon in people's basements, admittedly, but many employers are willing to allow employee equipment sign outs, and if you or a friend can do that, it makes a world of difference visualizing what's going on.

Regards

Blair

Re: Reversing loop with multiple trains in the loop

redking56@...
 

The reason that the literature is silent on that point is because it depends upon how the layout is wired and operated.

Consider a true reversing loop where the track folds back on itself. Assume that the loop is wired, polarity-wise, to match the straight through route leading into the loop and that the two non-tail ends of the turnout are gapped on both rails. With the turnout set to the straight through route, the polarities match as the train enters the loop, but the polarities inside the loop must be flipped as the train exits the loop. 

Now, the next time a train enters the loop, the polarities will be mismatched if the train enters on the straight through route, so the polarities must be flipped inside the loop upon entry. However, if the train enters the loop through the divergent route, the polarities will match, but the polarities inside the loop must be flipped upon exit.

In any event, the polarities are always flipped inside the loop in this situation because of the wiring and gapping protocol.

Hope this helps.

Rich

---In WiringForDCC@..., <ed_sargent@...> wrote :

Perfect, that is what was missing from my understanding. Nothing I have read pointed out exactly what was reversed, the section the train was leaving or entering.

Re: Reversing loop with multiple trains in the loop

Edward Sargent
 

Interesting, I was the original OP but I did not post on Digitrax as I am NCE. I liked your testing explanation, I have not seen a Oscope in years.

 

From: WiringForDCC@... [mailto:WiringForDCC@...]
Sent: Sunday, June 25, 2017 10:29 AM
To: WiringForDCC@...
Subject: Re: [WiringForDCC] Reversing loop with multiple trains in the loop

 

 

In case it matters to anyone, I believe the OP is using Digitrax, as he
posted this question to that list as well, and is now receiving advice
on both lists.

Even this analogy is flawed, but it's useful most of the time. If you
really want to know polarity/phase/amplitudes, get an electronics friend
who owns an oscilloscope to make a measurement of Rail A and Rail B
simultaneously, both referenced to the "ground" screw terminal in the
seven pin connector. Do this both

- with "analog" mode disabled

- with "analog" mode enabled, and address zero set to some decent
throttle position, say 50%.

Have him/her explain what you're seeing in both cases.

Then think about what happens to those signals when they are processed
by the onboard full wave rectification in a decoder.

To the OP:

If you do this, you'll benefit more than anyone just explaining what's
going on with analogies.

Blair

On 17/06/25 10:23, Ed S eschwerkolt@... [WiringForDCC] wrote:
> Ed,
>
> I am not an expert in DCC, but I did stay at a
> Holliday Inn once. So I will throw in my .02
> cents worth. The DCC voltage does not have
> polarity. It is AC as in alternating current; but
> not like the AC in the wall of your house. DCC is
> a higher frequency and a lower voltage.
>
> So what is the problem with reverse loops? Well
> the two rails carry different thing. One rail
> carries the commands from the command station and
> the other rail is more like a neutral rail. If
> you make a loop and it comes back on itself the
> neutral rail touches the command rail and that is
> the problem. Most layout programs will show one
> rail as red and the other as green and the rule
> is a red rail should never connect to a green rail.
>
> Now the really interesting part is the decoder,
> once it is set to tell the motor to run forward,
> it does not care if it crosses over and insulated
> section and the rails switch from red to green.
> The decoder/motor will still run forward.
>
> So stop thinking in DC….. There is no positive /
> negative rail in DCC. (But the locomotive motor
> is still DC but the decoder takes the AC from the
> rails and turns it into DC for the motor.)
>
> In addition; thinking more about the analogy of
> house AC wiring you would never connect the black
> wire (hot) to the white wire (neutral) in a house circuit.
>
> Now the experts should chime in and clear up any of my faulty logic.
>
> Ed S
>
> At 12:21 AM 6/24/2017, you wrote:
>>
>> Now that I better understand it I have more questions:
>>
>> · Exiting the loop the polarity is
>> reversed, but the next turnout can route the
>> train to another power district (same booster)
>> is something needed at every point where this
>> can occur or does the polarity reversal apply to the booster.
>>
>> · Same question except the turnout leads to a different booster.
>>
>>
>
>
>
> ------------------------------------
> Posted by: Ed S <eschwerkolt@...>
> ------------------------------------
>
> http://www.WiringForDCC.com
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>

Re: Reversing loop with multiple trains in the loop

Edward Sargent
 

Perfect, that is what was missing from my understanding. Nothing I have read pointed out exactly what was reversed, the section the train was leaving or entering.

 

From: WiringForDCC@... [mailto:WiringForDCC@...]
Sent: Sunday, June 25, 2017 5:09 AM
To: WiringForDCC@...
Subject: RE: [WiringForDCC] Reversing loop with multiple trains in the loop

 

 

Ed, when you set up a reversing section or reverse loop, it is completely isolated and gapped so that the polarity is only reversed inside the reversing section or reverse loop. When a train is exiting a reversing section or reverse loop, if the polarities are mismatched, the polarity inside the reversing section or reverse loop is reversed to match the polarity of the adjacent track. Same upon entry in that the polarity inside the reversing section or reverse loop is reversed to match the adjacent track. The polarity of the booster remains constant and is unaffected by the polarity inside the reversing section or reverse loop.

 

Rich


---In WiringForDCC@..., <ed_sargent@...> wrote :

Now that I better understand it I have more questions:

·       Exiting the loop the polarity is reversed, but the next turnout can route the train to another power district (same booster) is something needed at every point where this can occur or does the polarity reversal apply to the booster.

·       Same question except the turnout leads to a different booster.

 

 

Re: Reversing loop with multiple trains in the loop

Jan Boen
 

Hi all,

Technically the DC and DCC reversing loop are essentially the same. To avoid a short circuit at some point you need some electronics that will switch the signal on both rails.
The only problem you don't have with DCC is that your loco will not change driving direction when you toggle the signals on the rails.
Various COTS solutions exits where most will only resolve either the DCC or the DC problem.
If you want a solution that handles both then let me know as I built one just for this several years ago.

Cheers,

(Mr) Jan, from Belgium

Op 25 juni 2017 4:27:38 p.m. schreef "Ed S eschwerkolt@... [WiringForDCC]" :

 


Ed,

I am not an expert in DCC, but I did stay at a
Holliday Inn once. So I will throw in my .02
cents worth. The DCC voltage does not have
polarity. It is AC as in alternating current; but
not like the AC in the wall of your house. DCC is
a higher frequency and a lower voltage.

So what is the problem with reverse loops? Well
the two rails carry different thing. One rail
carries the commands from the command station and
the other rail is more like a neutral rail. If
you make a loop and it comes back on itself the
neutral rail touches the command rail and that is
the problem. Most layout programs will show one
rail as red and the other as green and the rule
is a red rail should never connect to a green rail.

Now the really interesting part is the decoder,
once it is set to tell the motor to run forward,
it does not care if it crosses over and insulated
section and the rails switch from red to green.
The decoder/motor will still run forward.

So stop thinking in DC.. There is no positive /
negative rail in DCC. (But the locomotive motor
is still DC but the decoder takes the AC from the
rails and turns it into DC for the motor.)

In addition; thinking more about the analogy of
house AC wiring you would never connect the black
wire (hot) to the white wire (neutral) in a house circuit.

Now the experts should chime in and clear up any of my faulty logic.

Ed S

At 12:21 AM 6/24/2017, you wrote:
>
>
>Now that I better understand it I have more questions:
>
>· Exiting the loop the polarity is
>reversed, but the next turnout can route the
>train to another power district (same booster)
>is something needed at every point where this
>can occur or does the polarity reversal apply to the booster.
>
>· Same question except the turnout leads to a different booster.
>
>

Re: Reversing loop with multiple trains in the loop

Blair & Rasa
 

In case it matters to anyone, I believe the OP is using Digitrax, as he posted this question to that list as well, and is now receiving advice on both lists.

Even this analogy is flawed, but it's useful most of the time. If you really want to know polarity/phase/amplitudes, get an electronics friend who owns an oscilloscope to make a measurement of Rail A and Rail B simultaneously, both referenced to the "ground" screw terminal in the seven pin connector. Do this both

- with "analog" mode disabled

- with "analog" mode enabled, and address zero set to some decent throttle position, say 50%.

Have him/her explain what you're seeing in both cases.

Then think about what happens to those signals when they are processed by the onboard full wave rectification in a decoder.

To the OP:

If you do this, you'll benefit more than anyone just explaining what's going on with analogies.

Blair

On 17/06/25 10:23, Ed S eschwerkolt@... [WiringForDCC] wrote:
Ed,

I am not an expert in DCC, but I did stay at a
Holliday Inn once. So I will throw in my .02
cents worth. The DCC voltage does not have
polarity. It is AC as in alternating current; but
not like the AC in the wall of your house. DCC is
a higher frequency and a lower voltage.

So what is the problem with reverse loops? Well
the two rails carry different thing. One rail
carries the commands from the command station and
the other rail is more like a neutral rail. If
you make a loop and it comes back on itself the
neutral rail touches the command rail and that is
the problem. Most layout programs will show one
rail as red and the other as green and the rule
is a red rail should never connect to a green rail.

Now the really interesting part is the decoder,
once it is set to tell the motor to run forward,
it does not care if it crosses over and insulated
section and the rails switch from red to green.
The decoder/motor will still run forward.

So stop thinking in DC….. There is no positive /
negative rail in DCC. (But the locomotive motor
is still DC but the decoder takes the AC from the
rails and turns it into DC for the motor.)

In addition; thinking more about the analogy of
house AC wiring you would never connect the black
wire (hot) to the white wire (neutral) in a house circuit.

Now the experts should chime in and clear up any of my faulty logic.

Ed S

At 12:21 AM 6/24/2017, you wrote:

Now that I better understand it I have more questions:

· Exiting the loop the polarity is
reversed, but the next turnout can route the
train to another power district (same booster)
is something needed at every point where this
can occur or does the polarity reversal apply to the booster.

· Same question except the turnout leads to a different booster.



------------------------------------
Posted by: Ed S <eschwerkolt@...>
------------------------------------

http://www.WiringForDCC.com
------------------------------------

Yahoo Groups Links



Re: Reversing loop with multiple trains in the loop

Flash Gordon
 

Ed,

I am not an expert in DCC, but I did stay at a
Holliday Inn once. So I will throw in my .02
cents worth. The DCC voltage does not have
polarity. It is AC as in alternating current; but
not like the AC in the wall of your house. DCC is
a higher frequency and a lower voltage.

So what is the problem with reverse loops? Well
the two rails carry different thing. One rail
carries the commands from the command station and
the other rail is more like a neutral rail. If
you make a loop and it comes back on itself the
neutral rail touches the command rail and that is
the problem. Most layout programs will show one
rail as red and the other as green and the rule
is a red rail should never connect to a green rail.

Now the really interesting part is the decoder,
once it is set to tell the motor to run forward,
it does not care if it crosses over and insulated
section and the rails switch from red to green.
The decoder/motor will still run forward.

So stop thinking in DC….. There is no positive /
negative rail in DCC. (But the locomotive motor
is still DC but the decoder takes the AC from the
rails and turns it into DC for the motor.)

In addition; thinking more about the analogy of
house AC wiring you would never connect the black
wire (hot) to the white wire (neutral) in a house circuit.

Now the experts should chime in and clear up any of my faulty logic.

Ed S

At 12:21 AM 6/24/2017, you wrote:


Now that I better understand it I have more questions:

· Exiting the loop the polarity is
reversed, but the next turnout can route the
train to another power district (same booster)
is something needed at every point where this
can occur or does the polarity reversal apply to the booster.

· Same question except the turnout leads to a different booster.

Re: Reversing loop with multiple trains in the loop

redking56@...
 

Ed, when you set up a reversing section or reverse loop, it is completely isolated and gapped so that the polarity is only reversed inside the reversing section or reverse loop. When a train is exiting a reversing section or reverse loop, if the polarities are mismatched, the polarity inside the reversing section or reverse loop is reversed to match the polarity of the adjacent track. Same upon entry in that the polarity inside the reversing section or reverse loop is reversed to match the adjacent track. The polarity of the booster remains constant and is unaffected by the polarity inside the reversing section or reverse loop.

Rich

---In WiringForDCC@..., <ed_sargent@...> wrote :

Now that I better understand it I have more questions:

·       Exiting the loop the polarity is reversed, but the next turnout can route the train to another power district (same booster) is something needed at every point where this can occur or does the polarity reversal apply to the booster.

·       Same question except the turnout leads to a different booster.