Decoder for N scale Atlas Dash 8-40B

french_guy Jul 4, 2021

  1. french_guy

    french_guy TrainBoard Member

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    I will give it a try.....
    Can I type that command from JMRI? Is there a serial monitor in JMRI?
     
    Last edited: Jul 6, 2021
  2. Ash

    Ash TrainBoard Member

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    For the serial monitor, there are two windows in JMRI:
    Send DCC++ command
    DCC++ Traffic monitor

    In the DCC++ Traffic monitor, I find it helpful to check the box at the bottom of the screen to show raw data.

    When you have 308 errors, use these commands to see some diagnostics.
    <D ACK ON>
    <R>
    <R 8 1 1>

    Paste the results in your reply, and someone might better identify if there are other settings needed.
    https://dcc-ex.com/reference/software/diagnostic-d-ack-command.html#more-detail
     
  3. CSX Robert

    CSX Robert TrainBoard Member

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    Did you try the 1k ohm resistor trick? (FYI - You probably can still program it, see below)

    The command station does not have to read anything back from the decoder when running.

    Well, you have at least 2 other options:
    1. The 1k ohm resistor on the track
    2. Don't worry about it and just ignore the error. The command station does not have to be able to read the decoder acknowledgment to program the decoder. The ack is just the decoder saying, "yes, I got it", after the CV is programmed. If the decoder is working correctly, which it sounds like it is, the CV gets porgrammed, even if the command station does not see the Ack and reports an error. This can cause issues writing an extended ("4-digit") address because it takes three writes - two writes for the address and one to enable it - and the command station may stop after the first write if it does not see the ack. In that case the solution is to either calculate the three CV values and program them individually, or program the address in ops mode, if the command station supports that, so that it does not look for the ack.
     
    Last edited: Jul 6, 2021
  4. french_guy

    french_guy TrainBoard Member

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    Well...............Is there a sticky named "How stupid I am", or something like that?
    I haven't touched my layout for a while. The last time I did was to modify some tracks....end of last year
    I had completely forgotten that I installed an isolated track between main and programing (linked to main in normal operation, and isolated when in programing mode)
    So I was trying to program the engine......on the insulated track !!!
    I just figured it out when I was trying to read several DCC engines, and they were all giving me the 308 error

    Do you think I'm in good position to be the "dumbest modeler" of the year? (n)
     
    Last edited: Jul 6, 2021
    Sumner likes this.
  5. MK

    MK TrainBoard Member

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    LOL! I can't say I have done that myself but I've done many other things that are just as bad. :) I've learned to just put things down and take a break when things just don't make sense. Often when you come back you have an "Aha!" moment. Sometimes scrutinizing things forever and ever just makes you look at the tree and not the forest.

    Glad you got everything working!
     
  6. french_guy

    french_guy TrainBoard Member

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    I think it was one of the biggest "Aha" moment of my life....and I'm 54 !!!
     
  7. BigJake

    BigJake TrainBoard Member

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    Been there, done that! Not exactly that, but plenty of other duh-worthy moments...

    The good news is that you persisted long enough to find the issue. Too many folks these days just throw up their hands.

    Sometimes you have to step away from it in order to get the old hamster wheel out of the rut that keeps you from seeing other courses of action.
     
  8. Sumner

    Sumner TrainBoard Member

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    Well actually the whole exercise turned out to be good for me, so thanks for posting.

    308 errors are going to come up and it made me take a more in depth look than I had before about the flexibility of DCC++EX in handling them. Not sure you have those options with any other DCC system. Thanks again to Fred and all the rest of the crew working on DCC++EX. It is becoming more and more a very viable DCC operating system that one can get into for very little expense,

    Sumner
     
  9. MK

    MK TrainBoard Member

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    Or worse, jump to a quick conclusion that the manufacture sucks and makes crappy stuff. Then they go spewing all over the internet about it when it really comes down to their misunderstanding. :whistle:
     
  10. french_guy

    french_guy TrainBoard Member

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    Engine is programmed, and runs just fine.......!!!
    I have 2 more engines to equip (1 x drop-in and 1 x wired)
    At least, I know now on which portion of the track I should program them............(y)
     
    BigJake likes this.
  11. FlightRisk

    FlightRisk TrainBoard Member

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    The DCC++EX diagnostics make this easy. It would have caught that there was zero current and no ACKs from the loco. So we would have had you check the wiring ;)
     
    Sumner likes this.

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