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!

consist issue

4874 views
22 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    November 2009
  • 52 posts
Posted by dcs077 on Friday, November 20, 2009 12:15 AM

 in my opinion i think the tsunami is an excellent decoder. the sound aspect of its operation is fantastic and i think the fact it has the hyperlight and hyperdrive features is just a bonus. even if it is not bemf it still works excellent. as long as it does what we want it to do isnt that all that all that really matters. if back emf is a priority then why buy a decoder that is predominantly a sound decoder. My 2 cents thats all just opinion.

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Thursday, November 19, 2009 7:00 PM

 Those three settings on the Tsunami are pretty much equivalent to the three BEMF adjustments on Digitrax decoders tha thave BEMF.

 ESU, CT, and other Euro decoders have even more adjustment for BEMF, but little explanation of whatthe variables are int he calculation, so it's a lot of trial and error to get the optimal settings, however sub-optimal in ESU is better than optimal settings with Digitrax.

                                     --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 2007
  • From: Christiana, TN
  • 2,134 posts
Posted by CSX Robert on Thursday, November 19, 2009 12:49 PM
davidmbedard
...Yes, I am aware....but I would like you to show me any documents on how to set it up...
The section of the manual that I quoted goes on for another two and a half pages describing what the CV's mean and how to go about setting them up.
davidmbedard
...Like I said, it is not a self-adjusting BEMF, it has to be set up to work properly.
Which is true of most decoders with Bemf compensation.

You said Tsunami's don't have "an official BEMF" which makes it sound like they don't really have bemf compensation but something similar instead. I just wonder what an "official BEMF" is and why is the one Tsunami's have not "official."

  • Member since
    February 2007
  • From: Christiana, TN
  • 2,134 posts
Posted by CSX Robert on Thursday, November 19, 2009 9:15 AM
davidmbedard
Actually, the Tsunami has hyperdrive, not an official BEMF...
I'm not sure what you mean by this statement, but Tsunami certainly does have Bemf . From page 47 of the Tsunami Diesel Sound User’s Guide:
Tsunami’s Hyperdrive system features high-frequency PWM drive for silent motor control along with load compensation (or back-emf) to improve low speed operation and maintain constant speed regardless of changes to the motor load.

The PWM frequency is fixed at 22.000Khz and there are no adjustments.

Tsunami uses back EMF and a PI control loop to sense and control motor speed. There are four CVs associated with the load compensation feature:

    CV 10, Back EMF Cutout
    CV 209, Kp Coefficient
    CV 210, Ki Coefficient
    CV 212, BEMF Feedback Intensity
  • Member since
    November 2009
  • 52 posts
Posted by dcs077 on Thursday, November 19, 2009 5:37 AM

 Success!  i was using too small values in cv2 i played around a bit and i found that a value of 38 worked perfectly. sitting the units on the track together but uncoupled and about half an inch apart  resulted in a nearly identical throttle response. it is true that the digitrax decoder does not have the great low speed control that tsunami does but now the only difference in speed is due to the lack of bemf in the digitrax. the locos perform perfectly in a consist but it would be better if i had a little reverse trim alteration. overall very happy. Thank you all for your help.

  • Member since
    June 2009
  • From: QLD, Australia
  • 1,111 posts
Posted by tbdanny on Thursday, November 19, 2009 12:09 AM
BEMF has been known to cause problems with consisting, a few of the guys at my club have run into it.  Given that you've got a BEMF and non-BEMF decoder working together, you might find that turning BEMF off on the Tsunami might go a way towards solving the problem.

The Location: Forests of the Pacific Northwest, Oregon
The Year: 1948
The Scale: On30
The Blog: http://bvlcorr.tumblr.com

  • Member since
    November 2009
  • 52 posts
Posted by dcs077 on Wednesday, November 18, 2009 11:34 PM

 thanks for all the info will try tonight and let you all know how it goes

Dan 

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Wednesday, November 18, 2009 5:51 PM

 You can get it to move at speed step 1 by adjusting CV2, but with a DH123 series decoder you'll never get the ultimate in slow speed eprformance, the DH123 does not have back-EMF. CHeck your value in CV54, it should be either 0 or 1 to turn on torque compensation, which helps but is not as good as BEMF, nor is it adjustable, it's either on or off. Getting a non-BEMF loco to run perfectly well with a BEMF decoder (the Tsunami has pretty good BEMF) is near impossible.

 For a much lower price, the NCE D13SRJ offers adjustable 'dither' to help customize slow speed running (still no BEMF). For the same price as the DH123 you can get the TCS T1 which does have BEMF. If you want to use Digitrax decoders, you need the DH163/DH165 series, those have BEMF.

                                        --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
    July 2008
  • 1,206 posts
Posted by mfm37 on Wednesday, November 18, 2009 3:40 AM

 Best advice is to reset the decoder to defaults. CV8 = 8. Then start making changes to  CV2 to get engine to start at speed step 1.

After that, changes to CV5 and Cv6 can be made to speed match if desired. DH123 does not have BEMF so any changes to those CV numbers won't have an effect. Torque Compensation is not BEMF.

Programming a 28 step speed table is another option. The speed table would need to be enabled in CV29 for it to work. Enabling speed tables turns off CV 2, 5, and 6.

  • Member since
    November 2009
  • 52 posts
Posted by dcs077 on Wednesday, November 18, 2009 3:21 AM

i would like to keep the digitraxx decoder but does anyone have any ideas how to get it to move the loco on speed step 1

i think that this is the main part of the problem. has anyone heard of any other decoders with the same issue?

 

  • Member since
    December 2002
  • 1,511 posts
Posted by pastorbob on Tuesday, November 17, 2009 11:35 PM

You may have been premature tossing the Digitrax.  I have run NCE on a three deck railroad, using 4 boosters since 1999-2000, have the latest upgrades and have consists running with Digitrax and NCE and TCE in the same consists with no problem.  I just keep tinkering.  My consists for the most part remain together from session to session, so once I have them set, I don't reinvent the wheel.

Bob

Bob Miller http://www.atsfmodelrailroads.com/
  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Tuesday, November 17, 2009 10:20 PM

cmarchan
What version of the NCE firmware are you using?

Which command station/booster do you have?

Which consist method (universal or advanced)?

 

 

I have the latest NCE firmware because I just replaced the EPROM in both my home and club systems; ProCab Radio throttles with 5 Amp PowerPro Command Station; Advanced consisting.  I was trying the Digitrax DH123 decoders.  Changed to NCE or TCS decoders and threw the Digitrax into the round file.

  • Member since
    November 2009
  • 52 posts
Posted by dcs077 on Tuesday, November 17, 2009 8:49 PM

 the decoder is a digitrax dh 123 and it is installed in an athearn genisis sd 70. the tsunami is installed in a ready to roll athearn sd 38. i have tried the digitrax decoder in 3 different locos and the result is the same regardless of mechanism. the loco will not start moving until speed step 12-15 on its own out of a consist as well. i am using the advanced consist but i have also tried the other method nce recommends in the manual which yielded the same result.the back emf is not set up on the decoder as i returned it to default. i did set it up but made no difference. the powercab is just the base model one no booster and unsure of firmware version.

  • Member since
    January 2004
  • From: Tarpon Springs, FL
  • 331 posts
Posted by cmarchan on Tuesday, November 17, 2009 1:48 PM

dcs077

    i am running an nce dcc system and i am having problems consisting 2 locomotives with 2 different brand decoders. the decoders in question is a digitrax  decoder and a soundtraxx tsunami tsu 1000. my tsunami equipped loco will start moving at speed step 1 but the digitrax loco will not move untill at least speed step 12. i have tried modifying cv 2 6 and 5 as well as the speed tables but it does not help. i am happy with the response from the soundtraxx decoder but is there a way to get the digitrax decoder to start moving the loco on speed step 1. changing to 128 speed steps only compounds the issue. any help would be appreciated

 

Dan 

What are the brand and model of each loco?  Ditto on DavidBedard's questions

Carl in Florida - - - - - - - - - - We need an HO Amtrak SDP40F and GE U36B oh wait- We GOT THEM!

  • Member since
    January 2004
  • From: Tarpon Springs, FL
  • 331 posts
Posted by cmarchan on Tuesday, November 17, 2009 1:41 PM

cacole

 After struggling with several Digitrax decoders that couldn't be speed matched and consisted with an NCE ProCab system, I ripped them out and put in NCE DA13SR or TCS T-1 decoders.  Consisted and speed matched on the first try.

IMHO, Digitrax makes great DCC systems, but their decoders don't play well when mixed with other brands.

Can you describe the issues you were having? I may be able to help. I have many Digitrax decoders in locos and have successfully consisted them using an NCE system(ProCab Wireless with three boosters).

What version of the NCE firmware are you using?

Which command station/booster do you have?

Which consist method (universal or advanced)?

 

Carl in Florida - - - - - - - - - - We need an HO Amtrak SDP40F and GE U36B oh wait- We GOT THEM!

  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Tuesday, November 17, 2009 9:30 AM

 After struggling with several Digitrax decoders that couldn't be speed matched and consisted with an NCE ProCab system, I ripped them out and put in NCE DA13SR or TCS T-1 decoders.  Consisted and speed matched on the first try.

IMHO, Digitrax makes great DCC systems, but their decoders don't play well when mixed with other brands.

  • Member since
    October 2008
  • From: high desert so cal
  • 997 posts
Posted by BIG JERR on Tuesday, November 17, 2009 7:55 AM

good question as I ve had the same problem ,got two matching atlas rs3 one with psunami at1000 other w/dh165 thought Id run em together same address but Ive never got them perfect so on some speeds I here wheels of one slipping a bit .... Id love to learn to consist em but Im still in learning mode so I will follow along ...J.W.

  • Member since
    February 2002
  • From: Westchester NY
  • 1,747 posts
Posted by retsignalmtr on Tuesday, November 17, 2009 7:13 AM

I have a couple of Athearn loco's that i added Digitrax decoders to. I found that I had to set CV2 to a value of over 100 to get them to crawl at step 1 on my DT400 ( CV values 0-255 ). Remember you cannot set CV 6 to a value lower than CV2 and CV5 to a value lower than CV6.

  • Member since
    November 2009
  • 52 posts
consist issue
Posted by dcs077 on Tuesday, November 17, 2009 4:48 AM

    i am running an nce dcc system and i am having problems consisting 2 locomotives with 2 different brand decoders. the decoders in question is a digitrax  decoder and a soundtraxx tsunami tsu 1000. my tsunami equipped loco will start moving at speed step 1 but the digitrax loco will not move untill at least speed step 12. i have tried modifying cv 2 6 and 5 as well as the speed tables but it does not help. i am happy with the response from the soundtraxx decoder but is there a way to get the digitrax decoder to start moving the loco on speed step 1. changing to 128 speed steps only compounds the issue. any help would be appreciated

 

Dan 

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!