Model Railway Forum

Hi all
I’ve just installed a new 8 pin DCC Concepts decoder into a new loco, all went well however after programming it I have to select reverse for the loco to go forward and forward for reverse. Any ideas how to correct this?

Regards

Hi
Initially try turning the 8 pin plug by 180° degrees and retest.

If that doesn't cure it then you will need a DCC system that can set CVs and adjust CV29 to change the direction of travel. Set CV29 to 7 or 39 if long addressing is used See this helpful guide... http://www.2mm.org.uk/articles/cv29%20calculator.htm
Or if you feel up to it swap around the two motor feed wires. However, I think swapping the plug around will cure it.

Even a basic DCC controller such as the Hornby Select can reverse the normal running direction.

Why do you assume he has a basic controller?

I’ve got a NCE Powercab so should be able to reprogram on CV 27 then.

Thanks

Its CV29 Not CV27

Opps typo error

Read CV29 first so that you know what it's currently set to then add 1, and write that figure back, so if it reads 6 write 7.

Paul

The Powercab has a quick method of reversing the normal (default) running direction without needing to read CV29, the Hornby Select and the Elite also have this ability, as do a number of other controllers.

On systems that require CV29 to be set manually you need to read it first and add 1 if its an even number or subtract 1 if its an odd number

I’ve changed the CV number by 1 and all now seems to be ok. Easier than having to take the tender to pieces to turn the decoder 180 degrees