1. Uncle peanut butter

    Uncle peanut butter TrainBoard Member

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    I shut the railroad down for a while over the past year and a half to make some changes. I have them completed and put my known, at the time, DCC equipped engine on the test track and get no response. The rear light comes on but that’s it. I’ve made a small change to the decoder program to see if the jmri decoder pro sees it. It writes to the decoder with no errors.
    Not sure where else to start looking. Any help would be appreciated.
    Thanks and hope all have managed to stay healthy.
     
  2. woodone

    woodone TrainBoard Member

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    How about some information has to witch locomotive and decoder you are working with?
    Scale, manufacture of loco & decoder will help a bunch.
     
  3. Uncle peanut butter

    Uncle peanut butter TrainBoard Member

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    Sorry about the lack of info.
    HO, older Atlas yellow box Alco C425, Digitrax DH165A0.
     
  4. woodone

    woodone TrainBoard Member

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    Have you tried a decoder reset? You stated that the rear light is on, can you change it so the H/L comes off?
    Do you have any control of the rear light?
    Still thinking a reset might fix things.
    Let us know what you find.
     
  5. Uncle peanut butter

    Uncle peanut butter TrainBoard Member

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    No, I can’t send any commands to the decoder. Rear headlight is on and I can only turn it off buy turning off track power.
    I’ll try a reset.
     
  6. woodone

    woodone TrainBoard Member

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    Well if you can not send a commands to the decoder you will not be able to do a reset.
    A reset is done by setting. CV 8 TO 8.
     
  7. Uncle peanut butter

    Uncle peanut butter TrainBoard Member

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    Asked Digitrax for support in resetting the decoder.
    Their reply:
    “I can't help you with DCC++ or the software you are using to reset the decoder. We do not provide support for 3rd party hardware of software.”
    CV8 is grayed out as if it’s set to read only.
     
  8. Uncle peanut butter

    Uncle peanut butter TrainBoard Member

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    I have made some changes to a CV just to see if it would see the decoder and successfully write the change. As far as I can see it was successful as no error messages were returned.
    I have a gut feeling this issue is something simple that I have done.
     
  9. woodone

    woodone TrainBoard Member

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    You are using DCC ++ ?I know not a thing about that system.
    Why can you not read back decoder data?
    When you set CV8 to a value of 8 it should read back the decoder manufacture, in the case of Digatrax it should read back 129 has a value. Then you enter a an 8 to reset.
     
  10. BigJake

    BigJake TrainBoard Member

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    Are you running in program on the main mode, or regular programming mode? Only the latter allows reading back the decoder registers, and it must be done on a track which contains only the locomotive being programmed.
     
  11. Sumner

    Sumner TrainBoard Member

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    How about a couple screen shots from DecoderPro of what it sees for the the decoder? For starters the screen when you hit the "Basic" tab.

    Will it do a full read of the decoder?

    Sumner
     
  12. CSX Robert

    CSX Robert TrainBoard Member

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    When you open the normal program window, CV8 is grayed out (for decoders that use CV 8 for reset) because you don't normally write anything to that CV when programming the decoder. If you open the single CV programmer (from the main screen, Actions -> single CV programmer), you can enter any CV and value. From that screen you can program CV 8.
     
    Uncle peanut butter likes this.
  13. Uncle peanut butter

    Uncle peanut butter TrainBoard Member

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    I’ll post one up today.
     
  14. Uncle peanut butter

    Uncle peanut butter TrainBoard Member

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    Had some success today. I put my C425 on the programming track and selected "Identify". Loco did a few jumpy back and forth motions. Placed it on my test track and it responded as it should.
    Not sure of why this worked but time to move to my next issue - DCC++ex and getting the wifi sorted.
    Thanks for all of your help.
     
    in2tech likes this.
  15. BigJake

    BigJake TrainBoard Member

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    On the programming track, a DCC system reads data back from the decoder by sensing current pulses from the decoder. When a decoder receives a programming command (not programming on the main), the decoder generates current pulses that can be sensed by the programmer. It generates these current pulses by pulsing the motor. Some decoders generate pulses by pulsing the motor in the same direction, which causes the loco to haltingly walk down the track. Other decoders alternate the direction the motor is driven to create the pulses, which tends to keep the locomotive from walking away (as far).

    I'm not sure why reading the decoder would fix your problem and make the decoder respond to commands.
     
  16. Uncle peanut butter

    Uncle peanut butter TrainBoard Member

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  17. BigJake

    BigJake TrainBoard Member

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    It could be that all the pulsing forward and backward while reading back the decoder settings freed up a bind in the locomotive's gear train...?
     
  18. in2tech

    in2tech TrainBoard Member

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    Sometimes things are a mystery. If it is indeed working correctly, time to move on. Just remember what you did to get it working for the future, in case your locomotive is possessed :) Now have fun!
     
  19. Doug Gosha

    Doug Gosha TrainBoard Member

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    It's par for the course with digital "electronics". "...try that and see if it works."

    Doug
     
  20. BigJake

    BigJake TrainBoard Member

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    Trying different things to see what works and what doesn't (aka "trial and error") is just basic trouble shooting, whether for digital electronics, software, basic electrical or mechanical issues. The combination of things tried and worked vs tried and not worked helps narrow down the potential causes, and can help direct further tests to identify the true problem.

    And the easiest things to try are often in the digital or software (e.g. JMRI) realm.

    When a locomotive responds on the programming track (assuming the same command station is used), that pretty much rules out electronics as the cause of the problem. There still may be electrical (i.e. layout wiring) problems, or mechanical causes.
     

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