DCC Back To DC

[wally]

When you run a Bachmann DCC equipped engine on a DCC equipped track, do you need to reprogram the engine to run on DC again? Thanks Wally

[ABC]

It depends, did you or somebody else program it to run on DCC only, or is it set to stop on DC by the manufacturer? If the answer to any of these question is yes then you will need an advanced DCC system like the Dynamis to change the CVs. The Bachmann E-Z Command System is not capable of this. But, unless you or someone else tampered with it, it will run fine on DC, but I would suggest removing the decoder and replacing it with the two little jumpers, which really seems to improve DC performance. If the decoder is in the board then this is not an option and too much of a hassle, so in this instance just leave it as is. But if it's a Spectrum or other loco with an 8-pin socket, then you can replace the decoder with the jumpers.

[Jim Banner]

ABC,
Have you actually taken a locomotive that was programmed for DCC only operation and changed its address with an E-Z Command, then tested it to see if it would run on dc?  As you know, in addition to changing CV1, the E-Z Command can also change CV29.  It sets or clears bit 0 depending on NDOT, and clears bit 5 to enable 2 digit addressing.  I suspect it does this by setting CV29 to one of two standard values depending on the NDOT that you select.  This would automatically set bit 2 to enable power source conversion.  But bottom line, I have not tested this either.

Wally,
If the decoder programming has not been changed from the factory presets, you can freely switch between dc and DCC operation without having to reprogram anything or move any jumpers.

I believe but have not confirmed that you can reset a locomotive with a Bachmann decoder back to using dc or DCC with a Bachmann E-Z Command by using the instructions for  REPROGRAMMING DECODERS WITH PREVIOUSLY ASSIGNED DIGITAL ADDRESSES (bottom of page 3 in the manual.)

Unplugging the decoder, if it is a plug in type, and installing the jumper plugs may improve the operation on dc.  But then you would have to remove the jumpers and plug the decoder back in to operate on DCC.  Most people that switch frequently between dc and DCC just leave the decoder alone and live with having to turn the throttle up a bit more to get the locomotive to start on dc.

Jim

[wally]

I am using a MRC prodigy express system. I changed the decoder address from 3 to the first 2 cab numbers on my spectrum 2-8-0 and 4-4-0. When I tried to run them again on DC they would not start.Thanks Wally

[PaulDeS]

Wally,

I use an MRC Prodigy Advance and when you change the loco address it changes CV29 to a value that stops DC operation. If you program CV29 to a value of 38 you will be able to run DCC and DC.

Paul

[Jim Banner]

I did the test I suggested above and yes, the Bachmann E-Z Command does reset the decoder to dc control (analogue control) enabled when you use the procedure to change the address on a decoder programmed to an address over 10.  Unlike what the instructions imply, the address does not have to be over 10 for these instructions to work.  It can be any address, known or unknown.  Bottom line, even if your buddy accidentally messes up your option to run on dc with his Prodigy Advance/Express, you can straighten it out again with your E-Z Command.

Just for the record, I did the test on two locomotives, one a Bachmann DCC on board and the other an Atlas retrofitted with a Digitrax DH143.  During testing, I also confirmed that if the headlights were left turned on when the locomotive was last run on DCC, they work when run on dc and are direction to boot.  This included the rear light on the Atlas locomotive which has a bit of special programming.  It is set up so that the direction has to be reverse AND f0 has to be on AND f1 has to be on for the the rear light to light.  I have several locomotives programmed this way so that when coupled back to back, only one of the other headlight comes on, depending on direction, but the rear lights never come on unless you turn on function 1 as well.

Jim