Fitting decoders to R3872

[Bighandz]

I have just purchased the above model and realise it needs two 8 pin decoders. One in the drive car for control and one in the dummy car for lights.

so far, so good.

Now we come to programming on my Elite.

Do I give both decoders the same address?

Or, do I need to give them separate addresses and then build a ‘consist’?

And do I have to mess around with the CV’s?

(Really hope not. The last time I had anything to do with a CV was 20 years ago when applying for a job. Suspect they might be different things.)

Any way, thanks for any help you all may be able to offer.

[LTSR_NSE]

The ‘simplest’ way (i.e. compatible with all DCC decoders & controllers) is to give both decoders the same address & then only on the decoder in dummy power car, change cv29 to ‘reverse running’ (since it faces opposite direction to the motorised power car.)

Setting up a consist or altering lighting options (without using cv29) are decoder-specific possibilities & you would therefore need to read the decoder manual (and possibly Elite manual) to configure these options instead.

[ColinB]

Generally because the way the DCC sockets are wired in these type of models, you don't need to touch CV19.

[Bighandz]

Thanks folks.

Slightly contradictory advice there but I will keep both in mind.

Will try without changing CV.

If that works, all good.

If not, at least I know what to try next.

Quick supplementary question.

I need two 8 pin decoders, can I mix decoders or is it best to use two of the same brand?

The reason I ask is that the guy I have bought this from is giving me a gaugemaster decoder, but I usually use Hornby.

Again any advice would be helpful.

[Fishmanoz]

Advice is different rather than contradictory, depends on loco wiring. And they’ve had a brain snap - it’s CV29 where you change the reverse direction bit and you’ll find how to do it in the stickies at the top of the forum, if needed.

And you can use different decoders with a simple Hornby 8249 as the second one.

[LTSR_NSE]

Thanks for the correction/confirmation Fishy - major brain glitch indeed. I originally wrote 29, then later inexplicably thought I’d made a typo & changed it to 19, now corrected back to 29. 🤦‍♂️

[Fishmanoz]

You fooled Colin as well LT.

[ColinB]

I must admit I just copied his post.

[Bighandz]

Again thanks to everyone for their help and input.

With regard to brain snap and glitches, I have them all the time.

Which is why I come here for help. Well that and the fact I still haven’t got to grips with DCC properly.

But I know that no matter how basic my question may be, somebody here will always have the answer.

again, my continued thanks to you all.