It can mean many things, like that the engine wheels are a tiny bit dirty so the power isn't getting thru to the decoder, or that the programming track isn't hooked up (i.e. a wire has come loose) or many other things. Sometimes just sliding the engine a few inches and trying again will work if it's just a dust issue. It could also mean the decoder isn't hooked up.
It could also mean the decoder has been 'locked', you have to unlock it to make any changes.
Except for my first-production-run BLI Hudson, I've never had trouble with the Zephyr where I've had to add resistors etc. to get an engine to program OK.
I occasoinally get the d nd display on my Zephyr when attempting to read back a CV value. I simply connect a small 12 volt light bulb to the rails then do the read again and most times it works.
Dr. Frankendiesel aka Scott Running BearSpace Mouse for president!15 year veteran fire fighterCollector of Apple //e'sRunning Bear EnterprisesHistory Channel Club life member.beatus homo qui invenit sapientiam
Could be, I never had a problem with QSI or ESU with my Zephyr, but I haven't seen one of the new Paragon2's yet.
<rant on>
I wish these other manufacturers would get it right, they're on to second and third generation sound decoders now, why is it that Digitrax can make a soudn decoder that does not cause short reset problems and can be programmed on any normal program track without a booster but QSI and Soundtraxx and now possible BLI can not? Instead we're supposed to replace out method of short protection with new more expensive 'intelligent' devices. My feelign is that the 'intelligence' just means hold off longer if a short still exists when powering back up, If you've seen the thread on adding keep-alive to decoders without them, notice it's NOT just a capacitor being connected, but also a resistor with diode in parallel with it. Why? because that's all you need to manage the inrush current! Apparantly only Digitrax can bother to include this on their sound decoder design.
I've never had either issue with my Zephyr though, even with multipel QSI and Loksound locos runnign, with a deliberate short across the track to see if I could reproduce the problem. No problem recovering from the short. Perhaps I didn;t have enough, but people report problems with 7 sound locos on a 5 amp booster, since the Zephyr is only 2.5 amps I figured 5 was enough. Plus 3 non-sound. Nope, no problems.
<rant off>
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
As for interpreting the display, "d nD" basically means "decoder not detected". The command station was unable to get back anything from the decoder that it could interpret as a valid response to a read or programming command.
-Fritz Milhaupt, Publications Editor, Pere Marquette Historical Society, Inc.http://www.pmhistsoc.org
David,
A Paragon2. It's one of the new 4-6-4 Hudsons.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Randy,
Is it possible that this is that old issue where you need the PowerPax or a resistor across the two programming track rails in order to get the Zephyr to read a sound decoder?
Yes I had the locomotive on the program track when I tried to read the CV.and it would comeback d na which in the Zephyr manual says "this means there is no acknowledgement from the decorder typically during decorder write operations." So does this mean the decorder is not working?
Thanks Billy 21
Did you put the loco on the program track, or was it still on the main? You can't read CV values on the main. The Zephyr uses a dedicated program track, you need a piece or two of track compeltely isolated from your main line, with a pair of wires connecting the track to the terminal on the Zephyr labeled Prog A and Prog B. Then try to read the settings of your loco. When you install a new decoder, ALWAYS try it on the program track first - if it won;t read or program, DO NOT put it on the main track, something is wrong with the wiring and putting it on the main might damage the decoder. The power ont he program track is low enough that it shouldn;t damage a decoder, even if it's wired wrong, that's why you should test there first
I had a loco on my track that won't do anything so I tried to read back the address programed in it. I brought up the PAGE mode then selected the LOCO key and displayed AD2, I then pressed the CV-RD key but instead of getting a reading back an adress I got d nD. What does this mean and where do I go from here?
Billy 21