Help with JMRI and Digitrax PR4

Rich_S Aug 17, 2019

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  1. Rich_S

    Rich_S TrainBoard Member

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    Up until just a few days ago my JMRI and Digitrax PR4 were working perfectly to program my DCC equipped locomotives. Yesterday I added a Digitrax decoder to one of my Atlas GP40's, programmed the decoder using my new DT500 throttle and all went well. I then wanted to add my locomotive to my JMRI roster, using the "Read All Sheets" function and that is when things took a turn for the worse. I plugged my PR4 into my computer, plugged in the PR4 power supply, started JMRI, selected "New Loco" and since I knew the decoder I just choose it from the list and opened the "comprehensive programmer". I then selected "Read All Sheets" and something happened that has never happened before, the locomotive started moving down the programming track at a slow and steady speed. I had to grab the locomotive to keep it from running off the end of the programming track. When I looked at all the CV values on the JMRI sheet, the vast majority of them had the value of 255. What could have gone wrong? Has this happened to anyone else? and if yes, what was the solution to fix this problem? Thank you in advance for any and all help.
     
  2. Massey

    Massey TrainBoard Member

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    My PR3 did this to me as well. I think the issue was with the PR3/4 and its com port. I had to clear it out and reconnect it and the problem went way. As for the read all sheets showing all 255, that is most likely just the placeholder numbers in JMRI that had not been updated.
     
  3. Rich_S

    Rich_S TrainBoard Member

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    Thank You Massey for the reply, but that did not fix the problem. Things I've tried so far:
    1. Re-installing the JMRI software
    2. Deleting and re-installing the PR4 driver software
    3. Checking the voltage of the PR4 power supply
    None of the above fixed the problem and the power supply definitely has an output voltage. I cannot find any information on the Digitrax site or internet for trouble shooting the PR4. At this point in time it looks like I may have to send the PR4 back to Digitrax for repair or replacement.
     
  4. mtntrainman

    mtntrainman TrainBoard Supporter

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    i seem to recall...5 years ago...when I did my last decoder with the PR3 and JMRI...the same problem. My memory is a bit fuzzy but I seem to recall on the first screen that opens...there is a 'Mode' selection area..I believe its on the top right. When I selected the wrong mode...I remember having those same issues.

    Like I say...my memory is fuzzzy. Worth investigating though IMHO.
     
    Last edited: Aug 19, 2019
  5. mtntrainman

    mtntrainman TrainBoard Supporter

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    if any suggestions so far havent helped....

    N scales own DCESharkman has done thousands of decoder installs and could probably help out. Message him.

    Mike Fifer has a good tutorial on the pr3 and Jmri...



    If all else fails try copying and posting your same question on the DCC forum. Those guys will have answers that will help I bet.

    https://www.trainboard.com/highball/index.php?forums/dcc-electronics.114/
     
  6. Rich_S

    Rich_S TrainBoard Member

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    Thank you George for the suggestion, I'll give that a try and see if anyone has any ideas.
    I've tried just about everything I can think of and still no go.
     
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  7. Rich_S

    Rich_S TrainBoard Member

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    A Quick update. A fellow modeler on the JMRI users group suggested I try a couple different locomotives to see what happens and that turned out to be a very good idea. As it turns out JMRI was able to identify the decoders in those two locomotives within seconds. I contacted Digitrax support with my problem and they did not have an answer why I could program my decoder in question with my DT500, run the locomotive on my layout without issue, but neither JMRI or Digitrax Sound Loader could read the decoder in question on the test track. The good news is there is nothing wrong with my PR4, the problem lies in the DN163A0 decoder. Since that decoder is currently working without issue, I'm going to call it good enough.
     
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  8. Rich_S

    Rich_S TrainBoard Member

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    Well folks, back to the drawing board. My JMRI and Digitrax Sound Loader program can't read the locomotives today, that they were able to read yesterday. :mad:

    Now I'm beginning to wonder, is it an issues with my PR4, the PS14 power supply or both? The voltage from my PS14 without being plugged into my PR4 is 15 VDC. The voltage on my test track with the PS14 plugged into the PR4 and after starting the JMRI program with a decoder equipped locomotive on the test track fluctuates between 7.34 and 9.46 VAC. Can anyone confirm if these values are within reason, too low or too high?

    Yes I know the DCC voltage is actually RMS Volt / Amps, but my Fluke meter does not have a RMS setting, so I'm just reading the voltage in AC for a close enough reading. Thanks in advance for any and all help.
     
  9. RBrodzinsky

    RBrodzinsky Staff Member TrainBoard Supporter

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    I would highly suspect the PS14. That voltage drop says it isn’t handling the load. You are not the first person I have heard of with similar issue.

    You may want to consider picking up a RRampmeter for accurate DCC measurements
     
    Rich_S likes this.
  10. MK

    MK TrainBoard Member

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    Hey Rich, I'm kind of agreeing with Rick as t0 have such a wide flucation between 7.34 and 9.46 doesn't sound right. Also note that the PS14 is a pretty "dumb" power supply. 300 mA output and I'm sure the voltage is not that well regulated, if at all.

    Under what condition does it show 7.34V and 9.46V or does it bouunce around like that constantly?
     
  11. Rich_S

    Rich_S TrainBoard Member

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    Hi Mike, Yes the voltage fluctuates without any rhyme or reason, but I see most of the fluctuation when JMRI is trying to read information from the decoder. If JMRI is in an idle state, the voltage stays around the 9.4 voltage reading. Which kind of surprises me a little considering the output of the PS14 is 15 VDC. I would think the voltage on the track would be higher than 9.4 Volts and here is the surprising fact, when I remove the locomotive from the test track, the voltage jumps up to 11.5 volts. Does a idle decoder really draw 2 volts? Hopefully my LHS will have a PS14 in stock as they are only $12.95 list, that's not going to break the bank.
     
  12. RBrodzinsky

    RBrodzinsky Staff Member TrainBoard Supporter

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    Locos draw current, not voltage. Are you measuring in Programming Mode, or Operations Mode? (Does a PR4 have an ops mode)?
     
  13. Rich_S

    Rich_S TrainBoard Member

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    Hi Rick, Yes that's true. But my question is why is there a 2 volt drop when the locomotive is placed on the programming track. To answer your question, I'm using the JMRI software with a Digitrax PR4 as a standalone programmer on a programming track. The JMRI is being used in programming track mode. I'm starting to believe the PS14 is the problem, but will not be able to confirm this until I'm able to get to the LHS and purchase a new PS14.
     
  14. Rich_S

    Rich_S TrainBoard Member

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    A quick update. A new PS14 did not fix the problem. It looks like I'll be sending the PR4 back to Digitrax for repair or replacement.
     
  15. Rich_S

    Rich_S TrainBoard Member

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    Update #2. The PR4 is not defective, it appears the problem is two fold and the second issues I stumbled upon by accident. A member of the JMRI users group sent me his port settings which indeed were different from mine. Once I change my port settings to the one he sent, JMRI and the PR4 were functioning properly.

    The next day I tried to use my PR4 and the JMRI software and I was back to square one, that is when I realized I had looked up a couple of things on the internet using Firefox before hooking up my PR4 and opening my JMRI software. So I rebooted the computer, hooked up my PR4, opened the JMRI software and it was running as expected. I have no idea why Mozialla Firefox Quantum 68.0.2 (64-bit) interferes with either my JMRI software or the PR4, but that appears to be the case.

    Now for the tech info:
    I'm currently running Windows 7 Home Premium 64 Bit with 8 gig of RAM on a Dell Studio XPS 8100 with an intel i7 CPU running at 2.8 GHz.

    The Port Settings are:
    Bits per second = 9600
    Data bits = 8
    Parity = None
    Stop bits = 1
    Flow Control = None
    FIFO buffers both set to high

    Hopefully this information will be helpful to anyone else who encounters this issue.
     
    MK likes this.
  16. RBrodzinsky

    RBrodzinsky Staff Member TrainBoard Supporter

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