# Which is the decoder in Walthers' HO EMD GP9?



## rva1945 (Feb 11, 2016)

It comes as DCC ready, but no info about the decoder.

In order to properly set it, I need to know the manufacturer and model.

I'd appreciate any help,
Robert


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## DonR (Oct 18, 2012)

If the loco box says DCC READY, it is a DC loco. You must
buy and plug in a DCC decoder. Check whether 8 or 9 pin
and order accordingly.

Don


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## rva1945 (Feb 11, 2016)

The box says DCC equipped and it has a decoder inside, but no hint about the manufacturer. I just bought the loco and once at home will check it later, thanks.


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## rva1945 (Feb 11, 2016)

https://picasaweb.google.com/105403795492677221295/6306885815651844017


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## DonR (Oct 18, 2012)

Don't know what decoder Walther's builds into
that loco, but if it's new you should get an
owner's manual. The loco would come with a factory
set address of 03 or 3. Some controllers can read
the decoder and state it's make. For most model
operations the NMRA standards means you can
run it on any HO DCC system. Why were you
concerned about the decoder make?

Don


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## wvgca (Jan 21, 2013)

manufacturer id is normally not a concern ... and any decoder should be able to set all basic cv values ..
for extended cv table values, the loco 'should' have come with a manual, if it was purchased new ...
the walthers site just says it's a dual mode 8 pin decoder, doesn't specifically list supported cv values on the page that i looked at
if your dcc system supports reading of cv values, the manufacturer id is on cv8, and version is in cv9
and here is link to nmra decoder manufacturer table ..
http://www.nmra.org/sites/default/files/standards/sandrp/pdf/appendix_a_s-9.2.2.pdf


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## rva1945 (Feb 11, 2016)

It came with address 03 as expected, it is running fine and turning in 14" radius!

As I use JMRI to program the decoders, I need to know which CV I can set. I guess its a Digitrax as many online references to built-in decoders in Walthers' mention that brand.

JMRI supports some Digitraxx decoders, I'll pick one with just two functions.

Robert


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## wvgca (Jan 21, 2013)

with jmri / decoder pro, just click on the 'ident' button, and you will find out what it is


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## rva1945 (Feb 11, 2016)

Talking about JMRI, so far I used two decoders, as I'm still testing, both remain in address 03.

When can I change that address? I guess it's one of the first steps when adding a New Loco.


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## DonR (Oct 18, 2012)

Yes, most of us immediately change the 03 default
address as the first operation after a test run.

Check our DCC forum and you'll see a list of
CVs and what they do. They will be the same
regardless of the decoder make.

http://www.modeltrainforum.com/showthread.php?t=5371

Don


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## Cycleops (Dec 6, 2014)

The basic CVs will be the same but some manufacturers give you additional options for light dimming, various light options, slow running for shunting and others additional features. You should be able to download a manual from Walthers site which will tell you what CVs control what. If it's a Walthers supplied one the functions will be basic.


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## rva1945 (Feb 11, 2016)

wvgca said:


> with jmri / decoder pro, just click on the 'ident' button, and you will find out what it is


When I click on Identify, I see this message in the status bar:

Programmer Status: jmri.ProgrammerException: programmer in use.

Then I deleted the loco and created a new one. In the Create New Loco window, after selecting it, in Active Address it says 0, can I put 04 and click on write? Will that write the new address?


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## rva1945 (Feb 11, 2016)

Weell I connected the decoder to the Programming Track and now it seems to write the values...but it doesn't do the job.

I tried with a New Loco... and clicked on Read Type from decoder, it says

Read MGF ID - CV8 but nothing happened in 5 minutes.

And each time I try it I must exit JMRI because whatever I try to do

Exception Programmer is in use (or something like that).


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## wvgca (Jan 21, 2013)

i'm assuming that you have the latest version of jmri [4.4 or 4.5.1] as well as the latest version of java [8.91] 
when you write the values, does the loco make a small twitch or movement indicating that that it has received and written the new cv value?


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## rva1945 (Feb 11, 2016)

No, I didn't notice any movement. But despite the warnings messages, I later found that somehow I managed to change the address from 03 to 04.

Anyway it was not straightforward so I can't tell how "it worked".

So far so good though I think something is not working here. There was no way of identifying the decoder.


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## wvgca (Jan 21, 2013)

what are you using to feed DCC to the track, a sprog? or ?


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## rva1945 (Feb 11, 2016)

I' m using DCC++ running in an Ardiino Mega.


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## wvgca (Jan 21, 2013)

i have a couple of arduino uno's , but motor shields haven't come in as of yet ... probably next thing would be to check track voltage, maybe with a standard bridge, should be 13.5vdc or slightly better 
at least it seems than you can write some cv's , but you should be able to read them as well?


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## rva1945 (Feb 11, 2016)

I finally made it work. Maybe there was a faulty wire. I place the loco on a piece of track connected as the programming track, it was identified as a Digitrax but as some different models, I chose one with two functions. Here are pictures of the decoder that came installed from factory:

https://picasaweb.google.com/105403795492677221295/6311245448472962785


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## wvgca (Jan 21, 2013)

glad that you got it sorted out ...


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## rva1945 (Feb 11, 2016)

And yes the loco moves a bit everytime a CV value is written. I changed its address from 03 to 5952, its loco number.

Tomorrow I'll bought a Rio Grande set of freight cars, and I hope the wooden base will be ready for assembly on next weekend.

Regards,
Robert


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