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Loco gone wild.

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  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Loco gone wild.
Posted by mbinsewi on Friday, February 21, 2014 1:49 PM

Hey guys,

I've been going through the fleet,  checking things out.  So, I have an Atlas (yellow box) GP40 with a Digitrax DH123.  I haven't run it in over a year, (does that mean I have too many? Whistling ), so I put it on the program track, made sure the throttle's L & R controls are at 0 speed, turn on the track power, the loco takes off, on it's own.  I know all about being anxious to get going and get things done, but......this loco wants to take off on it's own!  ( I do like that kinda attitude!) 

I don't remember any issues with it the last time I ran it.  Any suggestions?

 

Thanks!

Mike.

  • Member since
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  • From: 4610 Metre's North of the Fortyninth on the left coast of Canada
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Posted by BATMAN on Friday, February 21, 2014 1:52 PM

Your Loco has entered its teen years. As long as you have done a good job of instilling trust and respect both it and you should be okay.Smile, Wink & Grin

Brent

"All of the world's problems are the result of the difference between how we think and how the world works."

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  • From: Pittsburgh, PA
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Posted by JoeinPA on Friday, February 21, 2014 2:04 PM

Mike:

First I would try turning off the analog mode. If this doesn't work I would do a decoder reset.

Joe

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  • From: Westchester NY
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Posted by retsignalmtr on Friday, February 21, 2014 2:41 PM

Possibly the locos address is still active on one of your throttles and is picking up where it left off after not having been properly dispatched the last time you ran it.

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Posted by mbinsewi on Friday, February 21, 2014 10:29 PM

Ya know Brent, your right.......I just gotta learn to let go!  I did what I could to give a green light for the road ahead, and let it go.....we'll see what happens.....I know from experience that any of the following, or any combination of..........running out of fuel, running out of money, and getting hungry,  will change the current situation.

 

So, the loco runs fine in "DC mode", as with Digitrax, as I don't know how other systems work, if a loco is put on the track , and there is no decoder to pick up track signal, the mode auto-switches to DC.

and I checked all of the stacked address on the thottle, and this one is at 0 speed.  So I'm thinking it's the decoder.  I'll hook up the tester and see what happens.  I am a member of the Digitrax Yahoo group, not very active there,  as there seems to be an attitude, and lots of tech stuff I know nothing about.  So, I'll figure it out, eventually.

Thanks guys!

Mike.

  • Member since
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  • From: Alabama
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Posted by cjcrescent on Saturday, February 22, 2014 3:49 AM

Mike,

Joe has it right. The loco is set to run in DC mode as well. Turn that off, and the problem will disappear. Except for 3 locos, I use Digitrax decoders exclusively. When any loco I have did this, (take off when placed on the track), on the programming track JMRI read that the analog mode was still on.

Carey

Keep it between the Rails

Alabama Central Homepage

Nara member #128

NMRA &SER Life member

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Posted by mbinsewi on Saturday, February 22, 2014 7:56 AM

OK, so according to the manuals (when all else fails, read the instructions) there is no "on or off" for analog operation.  If you put a Digitrax decoder equiped loco on a DC powered track, the decoder automatically switches to DC, because it doesn't sense the DCC power.   Take the same loco, put on a DCC track, and the decoder senses the DCC and goes back to DCC operation.

I don't have any JMRI stuff. 

So, if the decoder is "stuck" in DC mode, the decoder must be bad, or, you need to tell me how to get it out of DC mode, because the manuals say nothing about this, as it's suppose to be automatic.

Thanks,

Mike.

  • Member since
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  • From: Southern Quebec, Canada
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Posted by Guy Papillon on Saturday, February 22, 2014 9:13 AM

You must change the value of CV29.

http://www.2mm.org.uk/articles/cv29%2520calculator.htm

Good luck

Guy

Modeling CNR in the 50's

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Posted by JoeinPA on Saturday, February 22, 2014 12:25 PM

Guy's link didn't work for me. Try this version: http://www.2mm.org.uk/articles/cv29%20calculator.htm

I agree with Guy - This is a very handy site.

Joe

  • Member since
    January 2014
  • From: central Ohio
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Posted by TomLutman on Sunday, February 23, 2014 2:06 PM

I just had this happen to me on a new install of a DH126. What stunk was I put it on the track right in front of a whole string of cars and the thing went screaming backwards into them.

I pulled it off the track real quick and tried again. Same thing. What I happened to notice was that I placed the locomotive on the main fresh off the programming track and the main was powered at the time. The throttle was set to brake and turned to 0. The solution was to unplug the control unit and plug it back in. All was better afterwards.

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Posted by jrbernier on Sunday, February 23, 2014 2:44 PM

mbinsewi
OK, so according to the manuals (when all else fails, read the instructions) there is no "on or off" for analog operation.  If you put a Digitrax decoder equiped loco on a DC powered track, the decoder automatically switches to DC, because it doesn't sense the DCC power.   Take the same loco, put on a DCC track, and the decoder senses the DCC and goes back to DCC operation. I don't have any JMRI stuff.  So, if the decoder is "stuck" in DC mode, the decoder must be bad, or, you need to tell me how to get it out of DC mode, because the manuals say nothing about this, as it's suppose to be automatic. Thanks, Mike.

Mike,

  From the factory, the Digitrax decoders are set up for 'dual mode'  CV29 is what controls this - If you are using a 4 digit address, the value in CV29 should be something like 38.  This allows DC/DCC auto select.  The 'first' thing I would do is RESET the decoder on the program track - Write a value of 8 in CV8.  This will RESET the decoder to factory defaults, so try it with a loco address of 3 and see what happens.  If it still does not work, you may have a fried decoder(or very poor track/bus wiring).  I would really suggest you get JMRI/Decoder Pro loaded on an old home computer and attach it to your Digitrax system.  Trying to program from the throttles usually leads to a mistake, and wierd results happen.

Jim

Modeling BNSF  and Milwaukee Road in SW Wisconsin

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Posted by dante on Sunday, February 23, 2014 10:29 PM

jrbernier

 

 
mbinsewi
OK, so according to the manuals (when all else fails, read the instructions) there is no "on or off" for analog operation.  If you put a Digitrax decoder equiped loco on a DC powered track, the decoder automatically switches to DC, because it doesn't sense the DCC power.   Take the same loco, put on a DCC track, and the decoder senses the DCC and goes back to DCC operation. I don't have any JMRI stuff.  So, if the decoder is "stuck" in DC mode, the decoder must be bad, or, you need to tell me how to get it out of DC mode, because the manuals say nothing about this, as it's suppose to be automatic. Thanks, Mike.

 

Mike,

  From the factory, the Digitrax decoders are set up for 'dual mode'  CV29 is what controls this - If you are using a 4 digit address, the value in CV29 should be something like 38.  This allows DC/DCC auto select.  The 'first' thing I would do is RESET the decoder on the program track - Write a value of 8 in CV8.  This will RESET the decoder to factory defaults, so try it with a loco address of 3 and see what happens.  If it still does not work, you may have a fried decoder(or very poor track/bus wiring).  I would really suggest you get JMRI/Decoder Pro loaded on an old home computer and attach it to your Digitrax system.  Trying to program from the throttles usually leads to a mistake, and wierd results happen.

Jim

 

I believe thay if you simply reset the decoder to factory default, you will continue to have the DC analog operation enabled. The first thing to try is to subtract 4 from your CV 29 setting-that disables DC operation. Any question, check the Digitrax website for calculating settings.

Dante

  • Member since
    May 2010
  • From: SE. WI.
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Posted by mbinsewi on Monday, February 24, 2014 5:46 PM

Success !  Thanks for all the coaching guys, and Jim, setting cv8 back to 008, and the factory default did it.  It brought the address back to 03, so I can start over again.  I programed the loco number as the new address, and I'm off and running.

Thanks for the help.

Mike.

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