DC & DCC

Is the model equipped with a dual mode decoder?  "One that can detect and run on DC layouts?"

Joe

Yes it is, it runs but goes

Yes it is, it runs but goes from reverse to forward at random time. I had done some cv changing with it and will see if a reset fixes

Decoder Issue

Most of the BLI Plymouth Switchers have DCC decoders installed. They will run on DC, but the microcomputer in the decoder is still running the engine. A voltage transient can send the uProcessor into never never land or in your case reverse. Most decoders can be set to run only on DCC by setting bit 2 of CV29 to 0 (zero) (See Configuration Bits page 47 of Paragon 2 Diesel Technical Reference Manual). But the standards do not specify a CV bit or function for locking decoders to run only on DC, so for DC operation CV29 bit 2 must be set to 1.

You should review the Advanced DC Motor Control and DC Motor Control functions and CVs described on pages 14-15 of Paragon 2 Diesel Technical Reference Manual. You may be able to reduce the sensitivity to transients by increasing CV250 DC Track Voltage Read Delay which is normally set to 0 (zero). Note that this will also slow down throttle response. If that does not work, addition of a keep alive would also reduce the probability of transients causing decoder issues. I would also send an email to BLI describing the problem as they may already have a solution.

Please let us know what happens.

ps. Another thought. If you have access to a DCC layout try running the engine on a DCC layout to see if there are any problems. If the engine misbehaves on a DCC layout you may have a bad or scrambled decoder.

DC

Resetting the decoder would be my first step.  Given you are running DC, the only decoder setting that may have any affect is to set the unit to run in DC only mode.  (Check the manufacturer's decoder options for this unit) 

If neither of these options work, the decoder may be defective.  

Joe

Track and wheel cleaning

Hello

I agree with both post above.  Also check the wheels and track.  I know if my dcc loco's are acting up 90% of the time it's dirty wheels or track.  

good luck

Tom R. 

Analog throttle?

It is DC,

,similar to the Athearn Throttles

Or....

Bypass the decoder entirely. Desolder the motor wires at the decoder board and solder them to the pick up wires. The lights may still get scrambled, but the motor will be reliable. Use a very small soldering iron.

pqe

Pulsing s module is the issue

I find that a "DC" signal with any voltage variation leads to confusion with the decoder.  Some manufacturers seem to do better than others, but it may just be the variation in a modules. I know the erratic nature is just that.  The same decoder type in similar drives does not respond the same to the pulse signal all other thing being equal.

I also find when I test using a classic fixed voltage DC signal all decoders respond as they should.  In most cases, the manufacture has a statement to that effect in their wright up on the decoder.  

Most DC power packs sold over the last 20+ years have some pulse signal.  Even those that say you can turn it off really do not turn it off completely.  Still enough pulse in the voltage to confuse the module.  

As Ken and Prof convinced me for my testing, a full wave or classic DC signal is best when running DC tests.  That is particularly true when running a drive with a DCC module.