New to DCC++

Bruceg503 Mar 23, 2021

  1. KC Smith

    KC Smith TrainBoard Member


    Thank you Bruce,

    Your Traffic Monitor show this decoder is not responding with any milAmps max=0mA
    and is not talking back at any length of time at all. ACK Acknowledge time Pulse = 0uS

    Please make sure you turned on the Power Button and it is Green
    and All four LEDs are on. which I'm sure you all ready did.
    Then check the AC voltage on the Prog track and let me know what it is.
    IF possible use a 14-18vdc, 2+amp laptop power supply connected to the Motor Shield

    Try Your Other good Loco decoder on the Programming Track and repeat the commands you used Above again First then see what a Good Traffic Monitor Conversation looks Like

    What does this bad response from your decoder mean;
    The First request

    <R 8 1 1> You asked to Read the Decoders Manufacturer number in CV8
    Prog Read Cmd: CV: 8, Callback Num: 1, Callback Sub: 1 JMRI received the request

    Unrecognized reply: '* ACK baseline=0/0mA Threshold=20/59mA Duration between 2000us and 8500us *'
    DCC++ setup is set to listen Between 2000 or .2sec and 8500 or .85 sec and wait for a decoder to respond.

    Unrecognized reply: '* V0 cv=8 bit=7 *'
    We tried to verify what was in CV1 bit 7 and we received 0 response

    Unrecognized reply: '* NO-ACK after 143mS max=0/0mA pulse=0uS *'
    Your Decoder is either dead or there wasn't enough Voltage or Current Amps to have the decoder power up and respond
    The Decoder never even coughed

    Unrecognized reply: '* V1 cv=8 bit=7 *'
    Unrecognized reply: '* NO-ACK after 145mS max=0/0mA pulse=0uS *'
    Unrecognized reply: '* Callback(-1) *'
    A positive response would have shown callback valid# 1 to 225 for a Mfr. number

    The Second Request above was to
    <R> Read the Address of the Engine and reply to me
    and the decoder responded the same. It should have recalled your Loco's Number or Address.

    A Couple of solutions. Try a higher vdc power supply to the Motor shield if you have one, but either way try this;

    First we're going to give this decoder much more time to respond
    by spreading the ACK Acknowledgement wait time in DCC++EX to 1000us to 1400us , or from .1 sec to 1.4 sec

    Use the JMRI Send DCC++ Command panel to send these commands
    <D ACK MIN 1000>
    <D ACK MAX 1400>

    and to lower the milamp to a lower current
    <D ACK LIMIT 10>

    Then send <R 8 1 1> request again for the Mfr ID again

    Your learning the New Powerful DCC++EX Diagnostics commands for Difficult decoders whether their Z, N HO or G Scale rated.

    We'll be here to help you out.
    Last edited: Apr 1, 2021
    Sumner likes this.
  2. Bruceg503

    Bruceg503 TrainBoard Member

    KC and ASH I really appreciate the input and help to understand the DCC++EX trouble shooting. I really do want to understand the CODE and how to change settings, etc...

    right now my setup is me laying on the floor with a track on a piece of plywood, swapping wires (main, programming) with a laptop, and 12DC PS to trouble shoot. Not Ideal. I am working on getting my single car garage cleaned up (we just remodeled half our house).
    Sumner likes this.

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