Made the Jump to DCC Today

[Herc Driver]

Finally, after years of wait, I have a Zephyr system up and running (albeit with some glitches at first programming a decoders).

My thanks to all who have provided their hints, tips and experience that shaped my DCC selection and ultimate layout setup.

I do have a question...regarding the decoder in a Bachmann HHP8. I haven't been able to program the decoder. Each time I've tried, I get a "d nd" error. I haven't been able to find out what make decoder is installed, and although trying several times, haven't been able to reprogram the decoder from the factory set - cv03 address - to the engines four digit road number. From the very little I know about decoders, I've read that not every one is reprogramable, and that some decoders are "set" at the cv03 address value. But I successfully reprogrammed two other decoders today, so at least I know I can follow the directions successfully to reprogram the diesel's address. The HHP8 engine works fine using the cv03 address on the layout. But I was hoping to change the address to match the diesel's road number. (As an interesting side note...when I first tried to reprogram the HHP8, it starting moving under power down the programming track - which I thought it wasn't ever supposed to do. I changed the track and wiring I was using for a programming track and the engine stayed still...but the Zephyr still gave me the "d nd" error and I couldn't read or write to the decoder.)

Any ideas why I can't reprogram this guy? :?:

[LynnB]

"d_nd" means "Decoder Not Detected" make sure you are wired ok to the program track. Do you have any other dcc engines you can try? Also make sure you have a clean track , dcc is fussy on having very clean track.

[Charlie B]

Herc ...regarding the decoder in a Bachmann HHP8
Are you able to run this with the 03 address? If so are you getting this error on the main or on the program track?
Some decoders require direct programming of CV17 and CV18 to assign a 4 digit number to a locomotive. I have the BLI program to give the CV values for four digit numbers which works great for BLI, but I don't know if you would get the same values in a different brand. There is more power to program on the main, but you don't have to address a locomotive on the program track.
Charlie

[Herc Driver]

The engine works fine using the factory pre-set cv03 on the layout. (Lights work in both directions, unit moves in both directions) I'm unable to reprogram the engine's address or read the current address on the programming track only. I successfully reprogrammed the address of two other dcc engines, one Atlas with a Lenz decoder and the other a Kato with a Digitrax decoder, on that same programming track so at least I know the programming track works. From what I've been learning so far about the Bachmann decoders, they operate at such a small voltage that the Digitrax systems can't "see" the decoder on the programming track. I've had one person suggest adding a 1000 ohm resistor to the programming track which should allow the Zephyr to "see" the decoder and program it successfully. I'm don't understand the electrical reason why the programming unit couldn't sense the presense of a decoder and that you'd need to add more resistance. I dunno...

I'm going to post this question to Digitrax and see what they say too, and if they reply, I'll post the reason and hopefully the "fix" here so others don't have to go through this.

Thanks again!

[Charlie B]

Herc, if you haven't tried it try programing it on the main. You won't be able to read the cv's but there is a higher voltage sent to the decoder. Too bad Deano is missing in action right now. I would think that adding a resistor would make it harder for the system to find.
Charlie

[Herc Driver]

Holy cow - I guessed right and it worked!

Thanks to a suggestion on the Bachmann Forum stating I should add more resistance, I increased the length of the programming track and added a Bachmann lighted Amtrak passenger car along with the HHP8 engine. I went through the programming steps to change the engine's address to the engine's road number - and it worked! I still don't understand why adding resistance allowed the Zephyr to "see" and write to the decoder...but it worked. Go figure.

[LynnB]

Holy cow - I guessed right and it worked!

Thanks to a suggestion on the Bachmann Forum stating I should add more resistance, I increased the length of the programming track and added a Bachmann lighted Amtrak passenger car along with the HHP8 engine. I went through the programming steps to change the engine's address to the engine's road number - and it worked! I still don't understand why adding resistance allowed the Zephyr to "see" and write to the decoder...but it worked. Go figure.

Wow first I've heard of this fix then again I can't say I've ever came across a problem with my programming, I use a programming track booster PTB-100 , I needed this when I first started installing and running tsunammi sound in my engines.

[Charlie B]

Holy cow - I guessed right and it worked!

Thanks to a suggestion on the Bachmann Forum stating I should add more resistance, I increased the length of the programming track and added a Bachmann lighted Amtrak passenger car along with the HHP8 engine. I went through the programming steps to change the engine's address to the engine's road number - and it worked! I still don't understand why adding resistance allowed the Zephyr to "see" and write to the decoder...but it worked. Go figure.

Herc, if all you did was put a put a lighted passenger car on the track, you dropped the resistance in the circuit and increased the current. That is why it worked. If you add a resistor in series you increase resistance. Now I understand what they were telling you to begin with which was probably to put the resistor across the rails. Anyhow, glad you got it running and I'll keep that advice in mind for when I have trouble.
Charlie

[Herc Driver]

It worked...and there was much rejoicing in the kingdom. Thanks for the explanation too! I can't exactly admit to understanding it perfectly, but with some more time with dcc under my belt in the future, I'll probably look back at this post and it will make more sense to my un-electrical dcc mind.