I have an Athearn loco with digitrax decoder that periodically won’t respond to commands. Usually when trying to slow down or stop, resulting in basically a runaway loco. Most times it will eventually stop at varying times or distances
It is not a plug & play so I had it installed by my local shop
I run it on the local club layout. None of my other locos or any of the other members locos act up so I can pretty much rule out track or DCS issues
When I have taken it back to the shop they can't seem to make it misbehave. Of course their test track is only 3' long ...not a layout And it does seem to happen after the loco has been running for a while
My questions is bad decoder? maybe try different address? (currently 7005)
It's not the address, unless someone else is using that address.
The gurus might want to know what make DCC controller you are using.
Henry
COB Potomac & Northern
Shenandoah Valley
using a digitrax DCS 100
As I recall, some dual-mode decoders occasionally lose connectivity on DCC unless the CV which allows dual-mode is set to DCC only.
It takes an iron man to play with a toy iron horse.
MisterBeasleyAs I recall, some dual-mode decoders occasionally lose connectivity on DCC unless the CV which allows dual-mode is set to DCC only. Add Quote to
That was the only thing I thought of, that is buried in CV29
https://www.digitrax.com/support/cv/calculators/
I've only ever heard of DC conversion being on causing a runway at system power up - if the track voltage is applied before a stable DCC signal is being generated, making the decoder think it is on DC powered track and taking off at near full throttle. Never actually seen it happen in all the time I've had DCC, or on the club layout.
Something that seems like you have no control is if CV3 (acceleration) or CV4 (deceleration) momentum values get set too high - but that's going to be consistent - if CV4 is set to a high number, it will ALWAYS take a long time for the loco to slow down, even if the throttle is set to 0. It does matter how fast the loco was going though, if you only got to say speed step 20, shutting down and stopping will happen a lot faster than if you had the loco moving at step 100 and tried to stop it.
Closest thing I've seen to an actual loss of control with Digitrax is at the club, if a battery goes dead in a wireless throttle. That user then has no control at all over their train until they swap out the battery.
Random speed changes with Digitrax can be caused by the same address used on more than one throttle (even the same DT40x throttle - since it's two in one). But that again will be fairly consistent until cleared out - if one throttle is set for speed 0 and you are runnign it with the other throttle, occasionally the loco will mysteriously stop, until you turn your throttle knob, then it moves back to whatever speed you set. Or the other way around, if the phantom throttle is set to step 100, and you slow downt he loco and then don't touch the throttle knob, it will suddenly speed up to step 100 until you adjust your speed again.
When the loco is uncontrollable - does the throttle display look normal, or does it go nuts and display garbage, indicating an issue with the throttle talking to Loconet?
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I've had this same thing happen when plugging 8 or 9 pin decoders into the light boards of Athearn locomotives. I had a few locomotives do this for me. At slow speed they just stop responding. Pushing or holding back the locomotive for a second or 2 usually causes it to start responding again.
I've found that the Digitrax decoders don't play well with the capacitors across the motor leads on the lightboard. I usually end up desoldering the caps from the lightboard and the problem goes away.
UPDATE took the loco to the layout to try a few more "ideas"
Back ground...the layout was originally built about 30 years ago as a travelling modular layout, now permanently set up at a toy mall. Obviously was originally DC but is convertable to DCC. Powered by Digitrax DCS100
NOW what I found.....the loco in question runs fine as long as it is the only locomotive MOVING on the layout. As soon as another loco starts moving the "bad boy" starts misbehaving. If I turn the headlights (headlight with ditch lights) OFF on the "bad" loco...everything is good, even with other locos operating.
I am thinking being an older layout with maybe under size buses loose rail joiners etc..that a voltage drop occurs & the load of the lights is just enough to cause issues with that loco/decoder
I have not looked underneath but believe that the power buses are not of adequate size.
If that turns out to be the case, it might be easier to just add a booster to part of the layout, especially if there's a long distance between your DCC system and the farthest trackage.