Directional lighting when direction is reversed on the decoder

[GWR FanBoy]

Hi,

I have a Bachmann 66 with a 21 to 8 pin adaptor and a TTS class 66 decoder. Everything works as it should.

I have recently bought a 2nd loco with the same set up- adaptor and TTS decoder. Using the Elite controller I want to reverse the running direction using the config menu but when I do all lights, white and red, come on and at the same time & the loco doesn't move. If I go back into the Config menu and select 'normal' direction rather than 'reverse' the lights work as expected and the loco runs.

I've also tired this from CV29. It read as 000 and I have tired it from 001-005 and the same issue persists.

Have I missed something here?

Thanks

[Rog RJ]

A value of 2 or 6 (or 3 or 7 for reversed running) would be more normal for a 2 digit address.

See this CV29 calculator http://www.2mm.org.uk/articles/cv29%20calculator.htm

PS. I would reset the decoder first and see if that helps.

[Fishmanoz]

It would be most unusual for CV29 to be 0, it’s likely being misread.

For a start, 128 speed steps (CV29 = 2) must be enabled for directional lighting. That also means it won’t work if your value is 1, 4 or 5 in your test.

So I agree with Rog that it should work with CV29 at 3 (reverse direction, no DC Running and 128 speed steps) or 7 (reverse with DC etc).

[GWR FanBoy]

Thanks Gentlemen. Unfortunately the problem still persists.

Set to 128 steps. When CV 29 is set to 3 all the lights on both ends of thr loco are on and it won't move. Setting it back to 0 corrects the lights and the loco moves again.

I'm at a loss!....

[96RAF]

As you are running TTS OK generally I take it your Elite firmware is up to date, if not what revision is it on.

My immediate thought was the 21-8 adapter is faulty, but odd that it works OK when direction is set to normal in Config. Are you using the 3-point speed table or the more complex multi-point option.

[Rog RJ]

Some 8 to 21 pin adaptors need a couple of pcb tracks to be connected by pieces of wire or zero ohm resistors (or should the existing links be broken?) for the functions to work, which may be the problem here.

[96RAF]

You reminded me of certain oddities on some adapters Rog - see here for one such fettle

https://www.strathpefferjunction.com/product/8-pin-to-21-pin-decoder-adaptor-dcc-nem652-8-pin-socket-to-21-pin-mtc-socket-da6/

[Rog RJ]

That is one that I looked at earlier and I think ESU also do one that needs some fiddling with.

[96RAF]

Its probably to do with some functions being logic signal and some full voltage Rog.

[Fishmanoz]

It’s more odd than a socket/adaptor fault. With CV29 on 0, it is on 28 speed steps and the lighting should not work.

What happens if CV29 is set to 2?