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!

Configuring CVs

1872 views
11 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    December 2006
  • 266 posts
Configuring CVs
Posted by jep1267 on Wednesday, February 4, 2009 6:53 PM

Sorry if this ihas been asked before, I was too lazy to do a search. I have a Prodigy Express that I'm using to run an N scale Atlas H15-44. I have the Atlas decoder direction but I'm un clear as to what it's telling me.

The Directions show CV 51 is for lighting effects and lists different Bit values next to different effects. I under stand hoe to configure CVs with the Prodigy Express but I don't get how to ent er these Bit values.

TIA

John

  • Member since
    February 2008
  • 8,877 posts
Posted by maxman on Wednesday, February 4, 2009 11:23 PM

It probably would have been helpful to at least tell everyone what decoder came with the engine.

The way I understand how this is done is as follows:

There is a range column and a default value column.

Each bit of CV51 has a range value of either 0 or 1.  The description column describes what happens when the value is 0, and what happens when the value is 1.

For each bit you have to decide if you want the 0 or the 1 to apply.  If you want the 0 to apply, you enter 0 in the default value column.  If you want the 1 to apply, you enter 1 in the default value column.

In the default value column there is already a number in brackets ( ).  What you have to do is add up the numbers in brackets for every box in which you entered a 1.  The total of the numbers is the value to which you would set CV51.

Give that a try.

Everyone else, if I've told him wrong please post the correct method. 

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Thursday, February 5, 2009 6:41 AM

 Nope that's exactly it. Generically, the bits are arranged just like decimal numbers, the higher 'place' to the left (like 100's, 10's, 1's) - remember palce value in grade school? 321 is 3 hundreds, 2 tens, and 1 one. 300 + 20 + 1

 Bit values are 128, 64, 32, 16, 8, 4, 2, and 1. So 10110110 is 1 128's, 0 64's, 1 32's, 1 16's, 0 8's, 1 4s', 1 2s', and 0 1's. Eliminating the zeros, it 1 128's, 1 32's, 1 16's, 1 4's, and 1 2's. 128 + 32 + 16 + 4 + 2 = 182. Put a 1 in each bit you need turned on, and add the values. The total is what you program in the CV.

                                                 --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
    December 2006
  • 266 posts
Posted by jep1267 on Thursday, February 5, 2009 8:06 AM

Max,

I wish I knew what decoader is in this loco. There seems to be some conflict over what it is. I was under the impression that it was a Lenz but I read somwhere that Atlas claims they don't use Lenz decoaders. Sigh

Ok, let me see if I understand this, Lets say I want the front headlight to function as a gyro light.

The CV is 51

The Bit Value is 4, 1 = HL functions as GyroDefault value is 0 with (16) in the brackets

If I understand correctly I should set CV 51 to a value of 21, correct?

John

 

  • Member since
    December 2006
  • 266 posts
Posted by jep1267 on Thursday, February 5, 2009 12:14 PM

Ooh Ooh! I get it! Not 21 but 22. Bit 4 controls the Gyro function but bits 1 and 2 are set to 1 from the factory and I don't want those to change. So, bit 4 has an equivilent decimal of 16. Bit 2 has an equivilent decimal of 4 and bit 1 = decimal 2.

2 + 4 + 16 = 22 right ?????

 

John

  • Member since
    February 2008
  • 8,877 posts
Posted by maxman on Thursday, February 5, 2009 12:42 PM

I really don't know, because I don't understand what all the different lighting effects mean, nor how they interact with each other.  Plus not having the decoder instructions in front of me also makes thing difficult.  Go to the www.atlasrr.com website, click on the "support tab".  There is a dropdown menu item called "manuals".  Click on that and a selection of different instructions will appear.  One of those is "Dcc decoder manual for Atlas N scale H15/16-44".  Is that what you have for instructions?  If so, I think the following link should take you directly to this document, http://www.atlasrr.com/DCC/N_H15-44Manual_Atlas.pdf.  Pages 7 through 12 have all the configuration variables.

I see on page 10 that bit 4 of CV51 would be one of the default values that needs to be changed.  If you want the headlight to function as a Gyro light the default value changes from 0 to 1.  Note that I believe that this business of changing the default value is really just a method of you keeping score as you go down the list of options.  Basically you are just saying "no I don't want this"or "yes I do want it".

Anyway, the number in brackets for bit 4 is (16).

Then there is a note regarding CV51 on page 11 that says bits 4 to 7 are effective if and only if CV51.0=1.  What they are talking about here is bit 0 of CV51.  If you look at the default value for this bit, it is 0.  So, you'll keep score by putting a 1 in this box.  The bracketed number in this box is (1).

You also need to make a decision regarding bits 1 and 2.  I won't pretend to know how those 2 bits interact with anything else.  But I do see that their default values are both 1, and the respective bracketed numbers are (2) and (4).

Therefore, the bracketed numbers you need to add up are (1) + (2) + (4) + (16), or a total of 23.  So you would set CV51 to a value of 23.  On the other hand, if you want to change what bits 1 and 2 do (ie, making their default values 0), you would decrease the total by the bracketed values { (2) and (4) } for these bits.  So then the number would be 23 minus 6 or CV51 is set to 17.

You'll need to check my numbers, and I hope you can follow the explanation trail.

Regards

  • Member since
    February 2008
  • 8,877 posts
Posted by maxman on Thursday, February 5, 2009 12:48 PM

jep1267
Ooh Ooh! I get it! Not 21 but 22.

I think the answer is "almost".  You missed the note on the next page of the instruction (see my post above) concerning bit 0.  You have to say "yes" to this, which adds (1) to your total.  So if we've both done this correctly, we both get CV51 set at 23.

Hope it all works out!

Regards

  • Member since
    December 2006
  • 266 posts
Posted by jep1267 on Thursday, February 5, 2009 2:15 PM

Yes, you're right! But I didn't miss the note I miss-read it Blush You're right though the CV 51 value should be set to 23 to make the HL a gyro. Cool I did use the instructions of the Atlas WEB site, Thanks!

  • Member since
    February 2008
  • 8,877 posts
Posted by maxman on Thursday, February 5, 2009 2:22 PM

jep1267

Yes, you're right! But I didn't miss the note I miss-read it Blush You're right though the CV 51 value should be set to 23 to make the HL a gyro. Cool I did use the instructions of the Atlas WEB site, Thanks!

I take it then that everything worked and that the headlight is flashing on and off, or up and down, or whatever motion it is supposed to simulate?  If so I'm happy that everything worked out okay.

Regards.

  • Member since
    December 2006
  • 266 posts
Posted by jep1267 on Thursday, February 5, 2009 5:54 PM

I don't know I haven't had a chance to try it. I just figured out how to do it. I'll keep you posted.

  • Member since
    December 2006
  • 266 posts
Posted by jep1267 on Monday, February 9, 2009 4:22 PM

Well it worked, I have a gyrating headlight. Thanks for the help guys

  • Member since
    February 2008
  • 8,877 posts
Posted by maxman on Monday, February 9, 2009 6:21 PM

Outstanding.  I love it when a plan comes together.

Regards

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!