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!

Speed matching and CV's?

4577 views
18 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Thursday, July 15, 2010 10:39 PM

 Yet another case where the Hex is EASIER. 102 - what the heck does that mean? there's no indication there that anythign is part of a value. Now in hex, as 66 - hey both halves are the same!  There are 16 values for each half of CV57, which is the BEMF intensity. 16 for running singly and 16 for when running in consist. 66 is about half strength on both. To turn BEMF off totally you want CV57 = 0.

                                                         --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
    May 2005
  • From: Riverside,Ca.
  • 1,127 posts
Posted by spidge on Thursday, July 15, 2010 9:30 PM

It was mentioned to set CV57 on the Digitrax to 102 so that the loco would have Bemf off accross the board. This way the decoder would run the same weather consisted or not. True?  I also heard the 102 is equal to 66 hexidecimal, but does this matter? As with any computer programing I don't care to learn the underlying binary codes to make things work.

John

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Thursday, July 15, 2010 3:00 PM

I guess it just comes down to knowing your system and it's idiosyncrasies

Springfield PA

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Wednesday, July 14, 2010 9:25 PM

 Yes, they chould consist fine on a default Digitrax system since CV19 does not come into play. However you cna chnge an option on the Digitrax system to make CV19 the default consisting.

 Consists created on an NCE system MIGHT be portable to Digitrax - NCE use a bit of a hybrid scheme so that it can easily flip the lead loco, like when you want to run the consist back the other way. If you know the value in CV19 you should be able to select it on a Digitrax system and operate the consist.

                                                 --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
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Wednesday, July 14, 2010 9:12 PM

Interesting.  So the Digitraxx default consist is the old style that stays with the command station.  That explains why some people with MTH loco's have no problem consisting.  If they're running DCC the default makes it run ok but th e loco's are basically being controlled individually.  When using NCE the preferred method is advanced which changes settings on the loco's. 

Springfield PA

  • Member since
    December 2001
  • From: Trois-Rivieres Quebec Canada
  • 1,063 posts
Posted by jalajoie on Wednesday, July 14, 2010 9:03 PM

spidge

So could I build an advanced consist on my Decoderpro Powercab oval and leave it in tact to run on the Digitrax layout? Since this would be decoder enabled consisting.

I own both a Digitrax and an NCE systems, when I built a permanent consist to be used on both systems, I built a CV19 consist using direct programming of CV19-CV21-CV22, I avoid using the NCE menu driven assistant and I run the consist by the consist address.

Jack W.

  • Member since
    May 2005
  • From: Riverside,Ca.
  • 1,127 posts
Posted by spidge on Wednesday, July 14, 2010 6:28 PM

rrinker

spidge

I to have issues with a couple locos causing the same issue. The Digitrax equiped loco will not slow down enough while in a consist on a Digitrax controlled layout when consisted with a TCS equiped loco. Yet I can consist the same two units on my NCE layout with no issues.

Any help would be appreciated.

 Simple, actually. Digitrax systems defult to command station consisting. All consist information is contained in the command station. NCE by default sets CV19 in the decoder.

 Why does this mattter? On Digitrax decoders with BEMF, there are two parts to the BEMF CVs. One part controls the BEMF settings when not in a consist, the other part controls the BEMF setting when in a consist - a CV19 consist, not a command station consist. By default, the consist CV settings in the digitrax decder are all 0, BEMF totally turned off. Hence the difference when runnign the loco in a consist on a Digitrax vs NCE system. Disable the BEMF totally and the Digitrax decoder will behave the same on both systems, but slow speed runnign will not be as good. You probably have BEMF turned off on the TCS decoder, or it's an older one before they had BEMF.

                                    --Randy

 

 

Thank for the explanation Randy,

So could I build an advanced consist on my Decoderpro Powercab oval and leave it in tact to run on the Digitrax layout? Since this would be decoder enabled consisting.

John

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Wednesday, July 14, 2010 5:09 PM

spidge

I to have issues with a couple locos causing the same issue. The Digitrax equiped loco will not slow down enough while in a consist on a Digitrax controlled layout when consisted with a TCS equiped loco. Yet I can consist the same two units on my NCE layout with no issues.

Any help would be appreciated.

 Simple, actually. Digitrax systems defult to command station consisting. All consist information is contained in the command station. NCE by default sets CV19 in the decoder.

 Why does this mattter? On Digitrax decoders with BEMF, there are two parts to the BEMF CVs. One part controls the BEMF settings when not in a consist, the other part controls the BEMF setting when in a consist - a CV19 consist, not a command station consist. By default, the consist CV settings in the digitrax decder are all 0, BEMF totally turned off. Hence the difference when runnign the loco in a consist on a Digitrax vs NCE system. Disable the BEMF totally and the Digitrax decoder will behave the same on both systems, but slow speed runnign will not be as good. You probably have BEMF turned off on the TCS decoder, or it's an older one before they had 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
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Wednesday, July 14, 2010 2:14 PM

I would suggest you start a new thread so the messages don't get mixed up.  When you start it include the loco's, decoders, and what you've tried so far.

 

Springfield PA

  • Member since
    May 2005
  • From: Riverside,Ca.
  • 1,127 posts
Posted by spidge on Wednesday, July 14, 2010 12:56 PM

I to have issues with a couple locos causing the same issue. The Digitrax equiped loco will not slow down enough while in a consist on a Digitrax controlled layout when consisted with a TCS equiped loco. Yet I can consist the same two units on my NCE layout with no issues.

Any help would be appreciated.

John

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Tuesday, July 13, 2010 6:20 PM

Yeah.  I'm usually latest and greatest with everything but I never delved into Decoder Pro.

I hooked it up once to My NCE PHpro and had mixed results but never gave it much time.

I'll be replacing my wife's laptop later this year.  Maybe I'll try again using her old one. Whistling

Springfield PA

  • Member since
    June 2006
  • From: Maryville IL
  • 9,577 posts
Posted by cudaken on Tuesday, July 13, 2010 4:53 PM

Hamltnblue
The reason for recording isn't whether or not you can read them but in the case you fry a decoder or one loses programming for whatever reason. 

 

 Yep, it has saved my butt a few times.

Hamltnblue
I'm not too familiar with decoder pro

 

 You got to be kidding, with all your postings? Decoder code is the best thing that happened to DCC! You use your computer (I know you got one Big Smile) to read and write and save CV's. Makes it very simple. Plus if you use Digitrax you can use it to run the trains. (it may work with other systems)

 The hardware I use is the Digitrax PR 3, with power supply it was like $65.00, but my LHS gave me a break. The owner wanted to see what I thought of it before he stocked it. Decoder Pro it self is free software.

 I don't know if it will read the goofy DCS decoders, but it will read your BLI and other decoders.

                    Ken

I hate Rust

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Tuesday, July 13, 2010 1:44 PM

The reason for recording isn't whether or not you can read them but in the case you fry a decoder or one loses programming for whatever reason.  I'm not too familiar with decoder pro but I'm sure you can save the loco files there which would be the same thing.

Springfield PA

  • Member since
    June 2006
  • From: Maryville IL
  • 9,577 posts
Posted by cudaken on Tuesday, July 13, 2010 7:01 AM

  I have no problem reading the CV's and keeping record of them thanks to my PR 3 and decoder pro. I take notes during the speed matching on paper. When they are matched, I have decoder pro read and save the CV's to the engines files.

 By the way Randy, thank you for correcting me on the terms I was miss using as well.

I hate Rust

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Sunday, July 11, 2010 7:35 PM

Agreed, Keep a log of every loco and the cv's you change.  You  never know when one will act strange and need a reset.  It doesn't happen often but it does.  Trying to re-do speed settings takes the longest if not recorded.

Springfield PA

  • Member since
    February 2002
  • From: PtTownsendWA
  • 1,445 posts
Posted by johncolley on Sunday, July 11, 2010 7:19 PM

Ken, the reason you can't read them is the SEB aka DB150 can't read decoders, only a Zephyr or DCS 100 Chief can. I have used a DB150 for three years, the trick is to do a reset then keep a log for each loco of every CV change you make! When you find a setting you like then underline it. John
jc5729
  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Thursday, July 8, 2010 9:45 PM

 Both decoders in question do Start, Mid, and Max. It will be hard to match start speeds witht he NCE to the Digitrax because the DH163 has BEMF and the NCE does not. Try turning of BEMF in the Digitrax.

 The speed numbers on the throttle go from 0-100, it's percentage, not speed step. CV2 comes in at the first click up from 0. CV6 will be approximately 50 on the throttle, about speed step 63 if you count actual steps. 128 speed steps aren;t 128 steps - a couple are reserved so there's really 126 actual speed increments. CV5 applies to 100 on the throttle, step 127. In between it's a straight line between the nubers - draw a chart with 0-128 across the bottom and o-255 goign up. Put CV2's value at the 1 goign across. Put CV6's value at the 63, and CV5's value at the 128. Use a ruler, draw a straight line between the CV2 and CV6 value, and naothe rlien between CV6 and CV5. That's how the locow ill respond. The steeper upward the line, the more the loco accelerates with each speed step. The flatter the line, the less difference between each speed step.

 Somethign else that helps when one loco just starts immediately even with 0 on CV2, and that is to put a slight bit of momentum in CV3. That will slightly slow down the response of the faster loco and might be enough to keep it from pushing or pulling the slower one.

                                                     --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
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Thursday, July 8, 2010 3:54 PM

You should try to match throughout the entire speed range.  You never know when a visitor might run your layout.

Also the range it works for you is pretty limiting IMO.

CV6 and 5 are good ways to speed match the range if the decoder supports them. Not all do and some do vlow and vhigh but not vmid. 

If you can't get it close you could write the entire speed curve.  It takes some time but is worth it. 

Springfield PA

  • Member since
    June 2006
  • From: Maryville IL
  • 9,577 posts
Speed matching and CV's?
Posted by cudaken on Thursday, July 8, 2010 3:47 PM

  My Digitrax SEB speed steep is sat a default which I believe is 128. If this is correct at what speed steep does CV 2, CV 6 and CV 5 kick in?

 Today I was speed match a Kit bashed Dash 9 (NCE decoder that Simon 1966 installed and for some reason I cannot read CV's or change them?) with a Athearn Ready To Repair Athearn that has a Digitrax DH 163 installed.

 I got them moving at the same time playing with the Dash 9 CV 2. Going by my DT 400 they where well speed match between speed step 40 to 45, which is fine because that is the speed I run the train most of the time. But, if I crank the speed up to say 50, the SD 45-2 will catch the Dash 9 in one lap round the 9.5 X 5 foot test track with the Dash 9 getting the head start.

 So, should I play with CV 6 or CV 5 in the Digitrax decoder for higher speed match?

              Cuda Ken

 

I hate Rust

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!