Funny, same thing happened to me just a couple of days ago when using my Zephyr to program a decoder. I have a circle of track I use for break-in runs that doubles as a programming track. I changed the four digit address to the engine's address; when I went back to track power the engine took off around and around on it's own.
I put the engine on the programming track I use with my laptop and brought up Decoder Pro. It turns out the problem was with CV29. Normally with the Zephyr, when you program a four-digit "long" address, it automatically adjusts CV29 to allow for long addresses. For some reason on this decoder (a Tsunami) it didn't do it, so the long address didn't 'take'. Once I changed CV29 to allow for long address and saved it to the engine, it worked fine.
BTW I didn't change the DC-compatability, but I have heard of engines having troubles that were cured by changing that.
Being a Digitrax decoder, Manufacturer ID is 129, found in CV8. Writing a value of 8 to CV 8 should initiate a decoder reset. Use the programming mode recommended by Digitrax, usually Direct Mode. The Digitrax decoder and DCS50 manuals can be downloaded from their website.
This decoder supports programming lock (CV15/16). If CV16=0 then it isn't active. Both CVs must be the same to disable the lock.
The DCS50 should have no issues doing a reset with this decoder using the program track. If it were a sound decoder, you may need to use a programming track booster. Cycle the track power to complete the reset.
Once completed, the decoder should be back to its defaults. CV29 should be set to 6, which activates the alternate power source (Analog for this decoder). Set Address 00 to minimum throttle if the loco runs away. It shouldn't do that unless the track signal is very distorted, causing the decoder to switch to analog mode.
Others have mentioned JMRI DecoderPro, a useful tool. To use it you will need an interface such as the Locobuffer or Digitrax's PR3 or PR4. The Digitrax units can connect directly to a program track, allowing you to configure the decoder with JMRI.
If you consider JMRI, install Java 11 as newer versions of JMRI will require it. You can use it in LocoNet Simulator mode to see what CVs the decoder supports.
Have you tried controlling it by its old address? If the reset didn't work then it could be running away because its old address is still in the stack at higher than 00 speed setting. If that's not the case, look fro a short between the rails/frame and the motor contact wings.
Martin Myers
Hi Betamax Sorry for not including the kind of decoder and Zephyr, the decoder is a plug n play DI163KC Nscale made by Digitrax, my Zephyr is the CDS50.
Regarding the "runaway", I agree with others that the analog feature/setting needs to be disabled. They've already explained why and how.
As far as it appearing the settings are not taking effect.....the age of your Digitrax Zephyr indicates it's an early version. In order to program some decoders, you need to set the Zephyr (command station) to the "Blast Mode" in order for it to have enough power to set the CV's
Some decoders need more power to program.....https://www.digitrax.com/tsd/KB33/programming-soundtraxx-tsunami-decoders-with-digit/
You didn't specify the brand of decoder, but I suspect this is might be the case.
Do you have the ability to use JMRI for programming? With this, you can see exactly what the CV settings are when programming.
Terry
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I had the same thing occur with two sets of F3 locos. CV29 controls a number of functions through individual bits. You want to make sure the analog feature is disabled. If it is enabled, you subtract 4 from whatever value is in CV29 to disable analog.
You should first verify that analog is enabled and this requires you to convert the decimal value in CV29 to a binary number. If the third digit from the right is a 1 in the binary value, analog is enabled. Subtracting 4 from the decimal value will set that digit to 0 disabling analog. If you don't know how to convert decimal numbers to binary, you should be able to find an online conversion application that will do it for you.
UPDATE: I found this handy little app to convert decimal to binary.
Convert decimal to binary (unitconverters.net)
Running away before the command station fully boots up is because DC is enabled in CV29. Not all decoders reset to factory defaults with CV8=8. NCE as an example uses CV30. It helps to know what decoder is in the locomotive. It also helps to know if someone has locked the decoder using CV15 and 16.
Why are you reprogramming your locomotives? Once they are addressed and set up there would really be no need to reset them and start over. Decoder Pro on an old laptop hooked to your Zephyr would be a benefit to you.
Pete.
That is because "03" is not the default address in all cases. So lets clear up a common myth...
If you bought and installed the decoder yourself (a retail decoder) the default address is required to be "3", a primary address with no leading zeros.
If the decoder was installed at the factory when the locomotive was made, the default address can be anything. In many cases it will also be "3" because they used an OEM version of the retail decoder where the firmware cannot be changed.
If you have an ESU LokSound, the factory or the installer sets the defaults. ESU supplies a blank decoder, which requires the installer or dealer to load the firmware and sound project desired. As part of this process they can configure the address and any other CV and set them as the default.
Before anyone can help you with this specific case, the make and model of decoder and model of Zephyr must be specified.
This decoder's address may still live on in one of the slots, and though you think it was reset, that didn't happen. When you apply power it gets the previous speed instruction and does its thing.
I have a question, I have the Digitrax Zepher, I've been using it since 2005, never had any problems with it at all, I was trying to program my locos back to factory settings 03, then program them to what I want, but the first one I worked with was a hell of a problem it would not program to 03, when I thought I programed it right, this particlaur loco would run on it's own, I mean when I turn on the power it would run BEFORE I would move the thorttle!!!! Help please Thank You