Headache with a Digitrax decoder in an Atlas SD9...

[Welshbloke]

I recently acquired an Atlas SD9 for a good price. Put it on the track, no headlights and it didn't move until I gave it a fair bit of juice. So naturally I thought "this has a decoder".

 

Took it to the clubroom to test on our DCC system and sure enough it does. It returned the Digitrax manufacturer ID code (useful as it meant I could find a manual) and I was able to do a factory reset with CV8, reset the address and it ran fine on DCC. But now it just sits there with the headlight on and doesn't move on DC...

 

I don't have DCC at home, so is there some snippet I missed in the manual about having it run on DC with directional lighting or am I going to have to source a DC circuit board to swap it back?

 

The only thing I did after the reset was program the four digit loco number as the address, so unless that also messes with the auto-sensing function the decoder is supposed to have I'm at a loss. Any ideas?

[inobu]

Your answer lies in CV-29. You have to check what CV 29 is configured for.

 

TCS is a easy to read calculator. You can see the bit position and its value.

 

Bit 2 and 5 are ON/1.  which correlates to the list to the left starting at Zero. 

 

If your DC is not working then bit 2 is not ON.

 

 

 

This shows the DC feature is cut off which changes CV 29 to a value of 32.

 

 

The way Binary counts is like this

 

 

Inobu

 

[Welshbloke]

Thanks - I shall try that next club night. Wondering if setting a four digit address causes the decoder to disable DC motor control or something equally weird. Never had this problem before, I have one or two other chipped locos in OO which are equally happy on both systems.