TCS CN decoder - can't set the locomotive address

[Bart1701]

I installed a TCS CN decoder a while ago in one of my older Atlas N Gauge locomotives. I did not reprogram the locomotive address and left it at 03. The locomotive ran fine.

Last night, I figured it was time to change the loco address to match the 4 digit road number on the locomotive.

I have a Digitrax Zephyr DCS50 command station. Set the engine on the programming track, set the 4 digit address to 2527. I read the address back and it showed 2527. So, all seemed good. Except that when I put it on the mainline and dialed up 2527, nothing happens. No lights, no movement, nothing.

So, I put it back on the programming track and reset the address to 03. The address read back OK, but when on the mainline, nothing happens.

Any ideas on what I should try?

Programming it on the Mainline in OPS mode? But, since you have to select the locomotive before going into OPS mode - will the decoder even be acquired when I select its number due to the issue described above?

Programming in OPS on the Main with Digitrax's Blast Mode enabled?

Doing a factory reset on the Programming track?

Any ideas are greatly appreciated!

Thanks,
Bart

[peteski]

If your DCC system can read back CVs on the programming track, you could check and verify the settings of CV29 and the CVs which hold the 2- and 4-digit (CV1, 17, 18) address are set correctly.  Obviously something is not getting set correctly.

[central.vermont]

Make sure you are in 4 digit addressing mode and not 2 digit addressing mode. Friend of mine just had this very same thing happen to him and that was what he was doing wrong.

Jon

[mmyers]

Read cv29. It's value should be 38 to run on its long address. When you wrote the new 4 digit address cv 29 may not have been changed. The original short address 03 would not be changed when writing a long address.
Martin Myers

[Bart1701]

Thanks for the suggestions.

I checked CVs 1, 17, 18, and 29 and read back their values. I saw 38 for CV1 - so it should accept 4 digit addresses. According to the calculator on the TCS site, I was expecting CV17 = 201 and CV18 =203 for 4 digit address = 2527. I did not see those values, so I coded them in. What should CV1 be set to after all this? That's the Primary Address - should it be 03, 2527, or something else?

Since I was not getting anywhere, I just played around with things and finally got it responding again with 2 digit addresses. It is set to 27 (the last 2 digits of the road number) and the engine responds as expected.

However, I'd still want to get the 4 digit address to work. Once I know what the values should be ( CV1 is the only one I am not sure about ), is there a specific order to program the CVs in. I read on the TCS site that you'd start with CV1 = 6 (the default with 2 digit addresses), program CV 17 and 18, and then set CV1 to 38(to use 4 digit addresses).

Out of all of the decoders I have installed and set to 4 digit addresses, this one is the only one that I've had issues with.

Thanks,
Bart

[nstars]

Thanks for the suggestions.

I checked CVs 1, 17, 18, and 29 and read back their values. I saw 38 for CV1 - so it should accept 4 digit addresses. According to the calculator on the TCS site, I was expecting CV17 = 201 and CV18 =203 for 4 digit address = 2527. I did not see those values, so I coded them in. What should CV1 be set to after all this? That's the Primary Address - should it be 03, 2527, or something else?

Since I was not getting anywhere, I just played around with things and finally got it responding again with 2 digit addresses. It is set to 27 (the last 2 digits of the road number) and the engine responds as expected.

However, I'd still want to get the 4 digit address to work. Once I know what the values should be ( CV1 is the only one I am not sure about ), is there a specific order to program the CVs in. I read on the TCS site that you'd start with CV1 = 6 (the default with 2 digit addresses), program CV 17 and 18, and then set CV1 to 38(to use 4 digit addresses).

Out of all of the decoders I have installed and set to 4 digit addresses, this one is the only one that I've had issues with.

Thanks,
Bart

It's CV 29 which should have 38, not CV1. To explain it quickly, CV1 has the 2-digit address and CV17+CV18 the 4-digit address. CV29 is used to switch between these two. A value of 6 In CV29 means that the 2-digit address is used. The 4-digit address is used with a value of 38 in CV29.

Marc

[Bart1701]

Sorry, that was a typo on my part in my post.

The value for CV29 was = 38. Not CV1 as I had typed.

So, the values I read were:

CV 29 = 38
CV17 = 201
CV18 = 223
CV 1 = 03 (...or what should it be ?)

Bart

[Bart1701]

...and a follow-up...

If I understand correctly, the value in CV1 does not get used when you're using 4 digit addresses? So, the value in CV1 is basically irrelevant when using 4 digit addresses.

The CV 29 = 38 tells it to use the 4 digit address in CV17 and CV18.

So, for locomotive number 2527 you'd need CV17 = 201 and CV18 =223 (looks like my original post had a second typo. It's been a rough day for me!). That's assuming that the calculator on the TCS site is correct.

Thanks,
Bart

[peteski]

Correct, when the CV29 is configured for a short address then the 4-digit address is irrelevant (unused - ignored). If CV 29 is set for long address then the short address is irrelevant (unused - ignored).  Some DCC systems however force you to use the 2-digit address if the address IIRC is <127 or on some systems <100. But this does not apply with your desired address.

I Googled for "dcc long address calculator" and found several online calculators. I tried the Digitrax one and the result was the same you got: CV17 = 201 and CV18 =223.  So that part is correct.  CV29=38 is also a correct setting for enabling 4-digit address.  Is is possible that your command station doesn't like that address for some reason?  How about trying to program the loco to a different 4-digit address you never used on your system? Maybe "1000"?  Then see if you can control the loco.

[Bart1701]

Thanks for the ideas, Peteski!

I tried to set the address to 1000. Even though all CVs read back as expected, the engine did not respond.

I was able to set the address to 99 and some other 2 digit addresses successfully. But, any 4 digit addresses fail.

I am going to contact TCS to see if they have any ideas. Maybe the decoder is defective? This is the 2nd CN decoder for this engine. I think I fried the first one and got the current one as a warranty replacement. If I get another one, I will hope that the 3rd time is the charm.

It's a neat idea to use this decoder for older locomotives  - to avoid milling the frame or having to do too much in the way of soldering wires - so I am willing to continue trying to get one to work as expected with a 4 digit address.

Bart

[nstars]

When you have set the decoder to the 4-digit address then try the decoder using the 4-digit address. If it doesn't respond then try the loco using the 2-digit address previously used. Don't change anything else, just try the 2-digit address. It will be interesting to see what happens.

Marc

[mmyers]

Also make sure CV19 is 00. If it has any value above 00, the decoder will be "consisted" and will only respond to its consist address in CV19. However, functions will still respond to its normal address.

[Bart1701]

When you have set the decoder to the 4-digit address then try the decoder using the 4-digit address. If it doesn't respond then try the loco using the 2-digit address previously used. Don't change anything else, just try the 2-digit address. It will be interesting to see what happens.

Marc

I tried this and it would not respond to the 4 digit address (2527) that was set with CV17 & 18, with CV29 set to 38. CV1 was set to 27. It would also not respond to the 2 digit address. The only luck I have had is with 2 digit addresses with CV29 set to 06..

I also checked CV19 to be sure it was set to 00 as another post suggested.

Getting ready to see a note to TCS to see what ideas they have.

Thanks,
Bart

[Rich_S]

Sorry, that was a typo on my part in my post.

The value for CV29 was = 38. Not CV1 as I had typed.

So, the values I read were:

CV 29 = 38
CV17 = 201
CV18 = 223
CV 1 = 03 (...or what should it be ?)

Bart

On my Digitrax system, setting CV29 to a value of 38 is an invalid number. Try setting CV29 to a value of 26 and see if that works?

[RBrodzinsky]

On my Digitrax system, setting CV29 to a value of 38 is an invalid number. Try setting CV29 to a value of 26 and see if that works?

That won't work, since it is bit 6 (32) that switches between 2 digit and 4 digit addresses. The typical value for CV29 is 6: 28/128 speed step (4) and DC analog mode on (2) and 2 digit address (0). Flipping to 4 digit address adds 32.

Digitrax provides a CV29 calculator http://www.digitrax.com/support/cv/calculators/#cv29_calc