Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Startup Speed Bursts

1312 views
6 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    July 2002
  • From: Bloom County
  • 390 posts
Posted by potlatcher on Monday, March 1, 2010 5:41 PM

Thanks for the several replied to my question.  I took your advice and turned off the DC setting on my problem engines.  So far, so good.

Tom

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Wednesday, February 24, 2010 6:35 AM

 Well technically not since NCE doesn't do zero stretching to run a DC loco, it's just the waveform being unstable for a second while the processor initializes at power up. The result is the same, since the decoder doesn't see a valid DCC signal it assumes it must be on DC track and acts accordingly. Turning off the analog operation with CV29 is the solution. Just remember you did it in case you later take the loco to a DC layout and wonder why it suddenly doesn't run. If you only run your equipment on DCC layouts there absolutely no reason to leave the analog conversion turned on, even on locos that don't seem to have a runaway problem.

                                                  --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    February 2010
  • From: Australia
  • 21 posts
Posted by tricky_trev on Wednesday, February 24, 2010 6:17 AM
yep. you're seeing the zero-stretching signal being read by the decoders. zero stretching is used for DC mode (loco address 00).
  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Tuesday, February 23, 2010 3:33 PM

Reprogram CV 29 to turn off DC operation in the decoders.  I always give CV 29 a value of 34 for a long address to start, which tells the decoder to run normal direction, 28/128 speed steps, and no DC operation.

 

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Tuesday, February 23, 2010 3:12 PM

You'll find your answer in CV 29.  Turn off the DC operation option on each loco.  Here's a CV29 calculator to make it easier. http://www.2mm.org.uk/articles/cv29%20calculator.htm

Springfield PA

  • Member since
    December 2001
  • From: Trois-Rivieres Quebec Canada
  • 1,063 posts
Posted by jalajoie on Tuesday, February 23, 2010 12:57 PM

If analog operation is enable, turn it off.

Jack W.

  • Member since
    July 2002
  • From: Bloom County
  • 390 posts
Startup Speed Bursts
Posted by potlatcher on Tuesday, February 23, 2010 12:23 PM

I have two or three decoder-equipped locomotives that sometimes take off running, just for an instant, when I power up the layout.  I would like them to not do this.  I am using an NCE Powerhouse Pro DCC system, and the engines in question all (I think) contain some older NCE decoders.  Is this a typical problem, and is there a way to keep it from happening without replacing decoders?

If this has been copied on earlier discussions, please point the way to the earlier threads.

Thanks,

Tom

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!