NCE/Digitrax problems

[jjb62556]

I have a NCE system at home..Digitrax at the club.. Have three engines with the same address that run great at home, not at the club. These are not in a consist and other engines run fine...What am I doing wrong...Thanks for any help...Jim

[peteski]

That is nowhere enough information, even for a wild guess.

First of all, what brand decoders are they?

Second thing is, what is the actual problem running them on Digitrax based layout?  More details needed.

Second is that I assume that you want to run them in a consist (all together).  Do they really all have the same address, or you have them consisted using NCE (advanced) consisting?  You might not even know you did that as NCE uses that consist as default (but forr simplicity it hides all the details behind the scenes).

Read CV19 (on the programming track) form those locos. If ht is not  equal zero, they are in advanced consist, and will only run when addressed by the address in CV19.

[jjb62556]

All Digitrax decoders, Not in a consist, on club Digitrax layout...Decoders are DZ126's...Jim

[C855B]

Have you tried a reset and start over? I'd reset and reprogram on the club layout and see if that still holds at home.

[peteski]

All Digitrax decoders, Not in a consist, on club Digitrax layout...Decoders are DZ126's...Jim

Well, if they are Digitrax decoders which work on NCE, but not on a Digitrax system, we sort of know what the problem is.

What exactly is their (mis)behavior on the Digitrax system?  Again assuming (I wish you would provide some more details - things would be much easier), those are non-sound decoders.

First of all, what is their address?
Second,  when you dial their address on the club's layout, do you get any responses?  Lights?  Motor?
Are you absolutely sure that CV19 on each decoder is equal to zero?  Have you actually put each loco on programming track and read it out?  I have to ask.

Also, what have you tried so far?  That will also be very helpful.

Please answer all questions - successful troubleshooting is based on information collected about the problem.  We are trying to help you. but with very little information we can only be guessing, and that is not a good way to troubleshoot.

Maybe if I sescribe hat we have here in slighty different terms, you will see that it is silly to expect answers with wvery little information given a bout the problem.

Think of it this way:  If you took your car to a mechanic and told him that you hear a slight noise, only when you turn left, but you wont tell him what kind of noise it is or if the noise is speed-dependent. You also won't let him examine the car, or take it for a test drive. Yet, you expect that with just the amount if info you gave him, not only the answer as to what the problem is, but you also expect him to tell you how to fix the problem, so you can fix it yourself.  Do you see my point? 

[learmoia]

A long time ago (10+ years ago) I remember a friend telling us about an issue he ran into similar.

He runs Digitrax, he took a pair of locos to a friends layout who runs NCE.
He runs the locos in consist on Digitrax on his lay out.. no problem.
He puts the locos on the NCE layout - consists them and they run fine..
Brings them home puts them on the Digitrax layout, dials up the lead unit sees the consist in Digitrax, but no response..

Long story short, the way I understood it..
After a bunch of research, he knew that Digitrax consists by linking Decoder addresses in system memory.

NCE consists by writing temporary values to decoders.. Not sure if they write the consist address or what, but they program changes to the decoder in a way that it doesn't transfer back to Digitax.

So resetting the address and the CV that tells the decoder what address to respond to and you should be OK.

EDIT: Woops.. just found the part about Not a consist..

Another idea I remember..
If your doing a 3 digit number one system likes a leading zero (to see it as a 4 digit address), the other system doesn't care..   

I even want to say that that a 2 digit address is technically 00-128 (or 255?) if this is the case, the leading digit only applies to '4 digit addresses' 0129-999 not 2 digit addresses 00-128.

So if you dial up 492 on your NCE system... When you go to the club, try to dial 0492

[peteski]

Well Ian, you have the addressing thing almost accurate. Addresses in the range of 1-127 (not any higher) and be configured as a "short" or "long" address. Some people call it "2-digit" or "4-digit" address (which is not quite accurate description).

Short address (1-127) is stored in CV1. Long address (1-9999 or even higher on some DCC systems) is stored in CV17 and 18.  Both addresses can coexist on the decoder, but only one can be actively used. Which one is determined by a bit in CV29.

Digitrax (and some other systems like CVP EasyDCC) force using short address for 1-127, and (by design) only long address for addresses <127.  NCE allows usage of both types of addressing for addresses 1-127.  That's where the leading zero comes into play (specifically on NCE systems).  When you are selecting locos address on the NCE throttle, if in the range of 1-127, if you add a leading zero, it  tells the NCE to force use of the long address when addressing that loco on the track. That's all it is for.  It is not stored in the decoder.  But CV29 in the decoder (set during decoder programming) tells the decoder whether to respond to long or short address.

The NCE throttle also shows whether the address in the range of 1-127 selected on the throttle is long or short.  Short addresses display a leading zero (like 024), and long addresses display an asterisk (like *022).  This is again NCE specific.

Knowing the problem loco's address would be very helpful to determine if this might be the problem, but for some reason Jim is hiding this info from us.

[jjb62556]

there is no response on the club Digitrax system. No lights or movement.  CV 19 is set at zero, Address is 0034 on all engines. Everything works fine on my NCE system at home.

[C855B]

Again, factory reset. Always the first thing to do when things aren't working as expected. Saves a lot of time and angst.

[peteski]

there is no response on the club Digitrax system. No lights or movement.  CV 19 is set at zero, Address is 0034 on all engines. Everything works fine on my NCE system at home.

That is very helpful.  Please let us know the values of CV1, 17, 18, and 29.

[jdcolombo]

The advice to do a factory reset is excellent advice.  Start there, re-program the address, and then see if the engines work.  Do this at the club on the Digitrax system.

If you don't want to do a factory reset for some reason, then at the very least you need to confirm that the address is REALLY 34 (e.g., a 2-digit address of 34).  Does the Digitrax system at your club have a programming track?  If so, put one of the engines on the track, and have it READ the 2-digit and 4-digit addresses.  You aren't really SURE that the address is 0034 until you have the Digitrax system read the value and confirm it.  Then check the value of CV29, to make sure that the decoder is set to 2-digit addressing.

I suspect that what is happening is that the decoders are actually set to 4-digit addressing, not 2-digit, and when you enter the address of 34 on the Digitrax system, it is trying to select a 2-digit address that isn't active or assigned to the decoder in question.  That's why Peteski wants to know the values of CV1 ("short" or 2-digit addressing) and CV's 17-18 ("long" or 4-digit address values).  But on a Digitrax system, you can simply read the short address value and the long address value directly; you don't have to read the values in CV1 and CVs 17-18.  Or at least you can with mine.

John C.

[peteski]

That is why I asked to please let us know the values of CV1, 17, 18, and 29.  Just resetting the decoder will not tell us what the problem is.  But having values of those CVs should  resolve the mystery.

Since we now know that the address is 34, I also suspect that short/long address "thing" is the problem, but it would be nice to confirm it.

[jjb62556]

CV-1 =3
CV 17=192
CV 18=034
CV 29=034

[peteski]

CV-1 =3
CV 17=192
CV 18=034
CV 29=034

Thanks!  That confirms what we suspected all along.  You set up your model (using NCE) to use address "34" in the long address range.
This is confirmed by CV29.  Value "34" indicates that you are using 28/128 step addressing and long address is selected.
CV1 shows that it still have the original default short address of "3".
When decoded, CV17-18 are set to a long address of "34".

Digitrax does does not allow addresses <127 to be in the long address range.

Solution:  Change the value of CV29 to a value of "2", and CV1 to "34", and then you will be able to run the model using Digitrax command station. No other changes are needed.
Remember that to address and control these locos on NCE system you will have to re-select the locos using address of just "34" (no leading zeros).  It will then be displayed as "034" (just to confuse things).

Isn't  DCC fun?    It is a simple 2-wire installation, much easier than DC with loco control. Sure, that is true, but it doesn't consider that the hidden complication is the programming.     Happy forth!  One good thing about this problem is that you have learned something you didn't know before.

[John]

CV-1 =3
CV 17=192
CV 18=034
CV 29=034

https://www.2mm.org.uk/articles/cv29%20calculator.htm