Model Railway Forum

I have had the same issue and I found that the programming track was not clean enough for the powercab to read the loco chip, maybe try cleaning the area you are using to see if that helps?

Hi

You haven't hit the NCE Powercab's Momentum button have you? This on the PowerCab seems to set decoders in a total spin especially sound ones! It IMO should never be used.

So, are you sure the Acceleration rates value isn't set very high? Try to set CV3 (and CV4 too) to an initial value of say 5, then retry on 128 speed steps.

In the event of you getting lost with CV settings, you can reset the Bachmann fitted decoder to its as manufactured settings including address back to 03 by CV8 entering a value of 8.

One thing else when trying to read or right CVs the rails need to be spotlessly clean so ensure you're are clean as too should the locos wheel treads be kept clean. It may be necessary to send programming instructions several times for the instruction to take. I have also found that apply light downward pressure on the loco can at times aid the programming, but here you really need the help of another person or some form of weight that be be temporarily fitted on top of the loco.

Sorry chaps deleted original post by accident. This really isn't my day.

Brian
Thanks for your comments. Yes I have pressed the momentum button. So wont be touching it again!
Will try and reset the decoder as you suggest.
I regularly give the track a clean with a track rubber, but will clean a specific area again. I don't use a programming track. Other loco's are in an isolated fiddle yard
Once again thanks for your input

The story so far?
I’ve managed to reset the decoder so that CV8 = 8.
Still no joy as to how it responds to the speed control.
I’ve found where the 128 speed steps are on the PowerCab (F12).. Not sure on how to use it though. Can it be set to 128 by default at all?
Bachmann have included some info about their decoder (Zimo MX644C) where it refers to various settings to obtain function/sounds. The F button has options; Latch or Trigger.
I don’t know what that means!!

Andyxx1 wrote: ↑Sat Jul 10, 2021 12:28 pm The story so far?
I’ve managed to reset the decoder so that CV8 = 8.
Still no joy as to how it responds to the speed control.
I’ve found where the 128 speed steps are on the PowerCab (F12).. Not sure on how to use it though. Can it be set to 128 by default at all?
Bachmann have included some info about their decoder (Zimo MX644C) where it refers to various settings to obtain function/sounds. The F button has options; Latch or Trigger.
I don’t know what that means!!

Glad to read you have managed a reset.
128 may remain but always check as sometimes I find mine is at 28 steps when turning it on.
Latch or Trigger. Simply means that when a Function is turned On it can remain on (Latched) or turns on then goes off again (Trigger) An example may be a loco whistle of horn. You would normally have that set to Trigger so as Pressing the appropriate F button the whistle sounds and release the button it stops and is ready to be sounded again. Latching may for example be used for lighting where you press the required F button and it latches that function On until that F button is pressed again.

Try reading what values are currently set in CV3 and CV4. If they are above say 10, reduce them to a value of just 1 or 2 and retest loco for moving off and slowing down. If the loco responses as expected then you can consider increasing these CV values a little to suit what acceleration and deceleration rates you require. Remember the higher the value number the longer it will take the loco to move off and reach the set speed or to slow down and stop.

Thanks for your reply.
I used to work where we had latching relay’s in control panels, so should have known what that meant. Was over 30 years ago though……
Your explanation of the values for CV3 & CV4 is superb.
Been on your web site, again, printed off the section on CV settings, will see if I can put it into practice.