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How to program for double heading locos?

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  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Saturday, January 4, 2014 7:39 PM

 Ohm they are the older ones with the driven fan? Yeah, that can change the starting characteristics, especially as neither decoder has BEMF. I have one of those old versionas as the chassis that came with an MDC RS3 kit, it has the flywheel with the pulley machined in for the rubber band, but none of the rest of it.

                 --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
    January 2007
  • From: Eastern Shore Virginia
  • 3,290 posts
Posted by gandydancer19 on Saturday, January 4, 2014 6:02 PM

I also use Decoder Pro for speed matching.  What I found to be the easiest for me is to use the User Defined Speed table.  You can go in and adjust step 1 on the curve to start with speed step 1, then adjust the curve shape.  I usually just have to set the slow speed, then the high speed, then Match Ends and get a straight line.  If I have to adjust the medium speed, I tweek each step as necessary, but most of the time this is not required.

Elmer.

The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.

(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.

  • Member since
    February 2004
  • From: Knoxville, TN
  • 2,055 posts
Posted by farrellaa on Friday, January 3, 2014 11:28 PM

I used DecoderPro to make all the adjustments and finally got them to run about the same speed all the way up to almost full speed. I changed CV2 on the slower engine until I got it to match the faster one, but didn' know what CV2 was in DecoderPro until I went back and checked the motor control and speed table settings and saw what had changed. Using Decoder Pro is differnt from just using CV's. I can see that I have a lot to learn about DCC programing. I never got both engines to start at speed step 1. The NCE loco worked out just fine but the Digitrax loco still won't start moving on Step 1; it starts about Step 3. I also remembered that I removed the fan and drive gear from the NCE loco but left them in on the Digitrax loco, which might affect the starting differences?? Just a thought; I may remove the fan from the other as I don't see any reason to keep them, you can barely see them through the grille and none of my visitors (family) even care or know that they are there.

Thanks for the help Randy. I may try to work with this again but for now they are connected and seem to  run fine as a consist (I made both address 737 btw).

   -Bob

Life is what happens while you are making other plans!

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Friday, January 3, 2014 12:37 PM

 Both those decoders have support for all 3 CVs, 2, 5, and 6. So you should be able to get plenty close enough without resorting to speed tables.

 For the DZ123, look at CV54 to see if Torque Compensation is enabled, this will help it start slower. You probably want this to be 64 or 65 (65 enables the switching mode, where everything is cut in half if F6 is on). Also check and adjust CV65 for the klick start. The NCE decoder has these adjustments as well, on different CVs. The first order of business is to adjust each one seperately so they start anbd run on speed step 1, using these drive adjustments as well as CV2. Then take the slower one and increase CV2 until they run the same at the start. At full throttle, adjust CV5 on the faster one to clow it down. You might not have to change the mid speed now, but at half throttle, adjust CV6 on one or the other, either speed up the mid throttle speed of one, or slow down the other, so they match. Only need to adjust one of them.

 If they will alsoways run together, use the same address, but change CV29 in the one to run backwards. If you plan to also run them seperately, you'll have to come up with a scheme to number them that you will remember. I have a set that are 300A and 300B - for this you could use something like 3001 for the 300A and 3002 for the 300B, but mine are drawbar connected for now so I just have them both at 300. Since I do have some actual pics of mixed loco consists, with an RS3 leading, an FA-B second, and an EMD F third, I eventually will have to change this so I can run the B seperate. Ah to model a road where the A and B units all got individual road numbers...

              --Randy

 

                 --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
    January 2011
  • 893 posts
Posted by PennCentral99 on Friday, January 3, 2014 10:27 AM

I would call the manufacturers of your decoders and see what they suggest. Here's why: I have Soundtraxx Tsunami's and according to Tech Support, CV 5 and CV 6 are not programable. In order to speed match, First, you need to change CV 29 to accept speed tables, then change CV 25 for user loadable speed tables. Once those are changed, you would need to adjust CV 66 (forward trim) and CV 95 (reverse trim).

If those CV's in your decoders are programmable for speed matching, then one needs to be re-addressed. Otherwise, you'll be sending out the command to 2 decoders.

Also, the procedures for setting up a consist for your particular command station may be different, consult the manual.

What's really scary - I actually understood what they (Soundtraxx) were explaining!!

Inspired by Addiction

See more on my YouTube Channel

  • Member since
    July 2003
  • From: Sierra Vista, Arizona
  • 13,757 posts
Posted by cacole on Friday, January 3, 2014 9:11 AM

Since they have the same road number, you have two possible choices:

1.  Change the road number on one of them and then create an Advanced Consist.

2.  Program both decoders to the same address, but change the value in CV29 in what will be the trailing locomotive to tell it to run backwards by adding 1 to whatever is in CV29.

If the decoders are going to have a long address, I would put a value of 34 into CV29 for the lead locomotive, and 35 into the trailing loco.  For a short address, CV29 would get values of 2 and 3, respectively.

  • Member since
    February 2004
  • From: Knoxville, TN
  • 2,055 posts
How to program for double heading locos?
Posted by farrellaa on Friday, January 3, 2014 8:49 AM

I have two P2K F2A's that I want to run as a double headed consist. What is the best way to program them so one always runs backwards or opposite the other? I have one with the road number already programmed and the second loco is still on 03. One has a Digitrax DZ123 decoder and the other has an NCE 13SR(?) decoder. Both have road numbers 737 but with A or D on the end. I don't plan to run them apart and they have non operating couplers on the 'B' ends, so I thought that would work to keep them together. The other issue is speed matching; not sure how to do this. I tried running them behind each other last night and the NCE decoder loco needs a higher speed step to keep up with the one with the Digitrax decoder, but the NCE one seems to respond smoother. I replaced the bulbs with LED's and not sure how they will respond to the programming for running as a consist. Any help or suggestions would be greatly appreciated.

I have been using Decoder Pro for my programming.

   -Bob

Life is what happens while you are making other plans!

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