Hi all-
I'm in the midst of a major cleanup of my track, and I wanted to tweak the starting voltage and address of my loco. I set up a temporary programming track to tweak this, but I'm having problems. Whenever I try to read CVs with my Zephyr, I keep getting a "dn d" error message, which according to the manual means the unit is detecting an open circuit.
I tested the track and a pulse of power is hitting the tracks whenever I try to communicate with a locomotive (which I've confirmed by placing my only other loco, a DC unit which gives me a "dn a" message) and also tried wiring my main track as the programming track, but had the same results. The locomotive runs absolutely fine otherwise, so the decoder seems to function fine otherwise, repsonding to all track commands.
Any suggestions would be appreciated.
Thanks!
~Rich
I should know better than to reply...but here goes. Does "dnd" mean decoder not detected? If so, and you know intuitively that your Zephyr has to be supplying power to the track you have set up, then you have a problem with continuity to or inside the decoder. It might be a broken lead to the decoder input, or something wrong in the decoder. Assuming you can make an analog DC engine move with the Zephyr, then you are indeed getting power to the tracks.
I don't recall reading here what the "dnd" means, something my Super Empire Builder and DT400 don't seem to produce for me. So, I'll sit back and try to learn something.
-Crandell
Sorry, I should have elaborated on those. Quoting from the Digitrax manual:
"d nd means there is an open circuit on hte programming track and no current draw is detected by the programiing track" This message appeared when I placed my decoder equipped loco on the track (the loco that functions fine when on the layout, but is non responsive on the programming track)
"d nA means there is no acknowledgement from the decoder typically during decoder write operations" This was the error message that came back when I placed my DC loco on the programming track and I think is reasonable to expect. I put it on there as a control of sorts, knowing it wouldn't "work" to see if I was getting any different kind of error message (if I got the same one, it told me there was a problmen with the control unit, which it apperas there isn't).
I hope that clarifies things a bit.
Thanks again!
Rich,
I'm not an expert by any means, but I have a Zephyr and an NCE PowerCab. I have about 2 dozen locos with decoders from Digitrax, Lenz, NCE, and TCE. I have had the same results you describe when trying to use the Zephyr to program some of the non-Digitrax decoders. I find that I can actually program them successfully, but can't read them back. I have to program one CV, then exit programming mode, then re-enter programming mode and program the next CV. I have verified the programming using the PowerCab, and all CVs get set properly. There just doesn't seem to be any way of confirming this using only the Zephyr.
I have never had a problem programming or reading out any Digitrax decoder with the Zephyr. There may be a minor incompatibility issue, but it appears that the Zephyr doesn't recognise the readback signals from some decoders from other manufacturers.
I should also state that my experience is with N-scale decoders only and that I have only used a few decoder models from each manufacturer. YMMV.
-Wayne
Thanks for that Wayne! I should mention I'm trying to program a Bachmann 70 toner which has the stock "el cheapo" DCC on board so I think your experience may be the same as mine. I'll report back if that isn't the solution!
I've used decoders made by Digitrax, NCE, and TCS (both pre and post BEMF) with my Zephyr and they all read back just fine. Problem decoders others have reports in particualr are the Bachmann ones. These usually can be made by putting a resistor (the one included with the Zephyr in the LT-1 Loconet Tester bag is perfect for this) across the program track. This seems to ahppen on other DCC systems as well, but mostly Digitrax -my feelign is the cheap bottom of the barrel Lenz decoder that is resold by Bachmann uses the absolute minimum pulse per NMRA specs (since Lenz makes a huge deal about EVERYTHIGN they make having the conformance football), and Digitrax finds that just a bit below threshold. You can try using slightly heavier wire to the program track (a foot of #18 hooked right to a piece of track would be good) and making sure it is VERY clean, as well as make sure the wheels of the loco are also very clean. And make sure you have the wire inthe right holes on the Zephyr connector - the two program track leads do NOT go next to one another - the ground connection is in the middle. PGM - GND - PGM
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Well, I tried out a last test before bed and I'm still having issues. Even ignoring the errors, I'm not getting through to the loco even to change it's address. I tried ops mode programming as per the included instructions, but I coudln't get things to work their either. I would put in variables to program, only to have the screen flash "busy". I left just before you posted, Randy, but I will try your theory tomorrow.
Thanks again to all for the quick replies.
~rich
Diito on the resistor across the programming track rails. This helps with some decoders that do not draw enough current during the acknowledgement which yields the d na code. The added resistor causes a higher current to be drawn when the decoder "acks" (decoder resistance plus 1kohm). Try using Direct mode programming. Keep pressing the program button until Pd is displayed, then program.
Martin Myers
I've been able to program Bachmann decoder-equipped engines with my Zephyr, although after a break-in run they usually get replaced with a better decoder. I would double check your "temporary programming track" to be sure it's wired correctly. The Zephyr output terminals are a little different from other powerpacks and it's easy to get the wires connected to the wrong terminal...plus of course make sure the connections at the track are solid.
If possible, borrow a DCC engine and try reading it's ID no. or other CV on your programming track. The fact that your DC engine came up with the "DN A" message doesn't mean anything, if you have no engine on the track it will give you the same message. If it won't pick up the other DCC engine, it means there's a problem with the programming track. (Believe me, I've spent plenty of time trying to figure out what went wrong with an engine, only to find out the programming track was the problem!! )
If that seems OK, try moving the engine a little. I've had situations where maybe a little fleck of dust or something has gotten under a wheel and isn't allowing the power to reach the decoder. Sometimes just sliding the engine back and forth a little will clear that up. Remember the power of the programming track is less than the standard DCC 14V AC, so it's possible it's getting enough power to run but something isn't allowing enough power thru to program the decoder. (BTW, that power difference is why you always should test a new decoder installation on the programming track first; if there's a short circuit it will detect it without giving the engine enough power to fry the decoder.)