Runs on DCC but not on DC

[PaulDeS]

I just received my second DCC On-Board engine (4-8-4 Niagara) to go along with aF& style diesel, also DCC On-Board. I ran both for a while, in both systems. After a time of running in DCC I decided to switch my layout to DC, ran an old DC engine with no problem but now neither of the new DCC On-Board engines will run in DC.

Any idea as to what happened. Both engines run fine in DCC but do nothing in DC

[richG]

I suspect you have to adjust some CVs to run on DC. At least that is what I had to do with a Tsunami equipped steamer.
According to the Bachmann Quick start guide, you have to enable the Analog mode. The Quick start guide does not say how to do this. You must have documentation that came with the locos.

Rich

[Jim Banner]

I just received my second DCC On-Board engine (4-8-4 Niagara) to go along with aF& style diesel, also DCC On-Board. I ran both for a while, in both systems.

Are you saying that for a while you successfully ran your Niagara and ?? diesel on dc and on DCC?  But now these two locomotives will no longer run on dc?

If so, that means that something has changed between the time they worked and the time they would not work on dc.  Do you have a DCC system that lets you change CVs?  If so, did you change any?  Once we know that, we can give you some advise without just making wild guesses.

[Yampa Bob]

Yes, I would like to know what controller you are using.  This is interesting.

[PaulDeS]

Problem now solved, thanks to RichG for suggesting that a CV must be out of order.
Yes, both engines did run in both DCC and DC when I first put them on the layout. I'm using an MRC Prodigy Advance2 system and it turns out that when I changed each engines address to a 4 digit road number the MRC system automatically changed CV29 from 6 to 34. After downloading a CV29 table from MRC's website I found that CV29=34 disabled analog operation. Fortunately the table indicated that setting CV29 to 38 would restore analog operation. By the way if I used a two digit address CV29 was automatically set to 2 which also disabled analog. For a while to only thing that worked was to set address at 3 and CV29 at 6 (the original settings), this allowed DCC and DC operation but isn't too convenient for multiple train operation.
So now everything runs as intended,  aren't computers great.

Thanks again

[Hunt]

Problem now solved, . . .

What you have discovered is what some of us familiar with DCC refer to as an undocumented feature. You will discover even more strange implementations by MRC of the NMRA DCC Standards and Recommended Practices. MRC seems to just do their own thing. Sometimes the folks at MRC seem to be as surprised about some of the undocumented features that surface in MRC DCC command stations and decoders as the rest of us.

That said, I always suggest … one of the first thing to do when using DCC is to change CV29 on any decoder to disable Power Source Conversion. This eliminates several possible unexpected anomalies. Very important to do this if running on an old club layout that was converted from  DC power to DCC.


Those going back and forth between DC and DCC be prepared to face the need to start over and reset the decoder’s CVs back to their factory CV value at anytime.

[Yampa Bob]

The more I read about these CV issues, the more I appreciate my E-Z Command Controller.  I turn the knob, the loco moves...that's all I can handle at my age.  My doctor told me not to be involved with anything that might increase my blood pressure.  I didn't tell him I was a model railroader.   

[Hunt]

The more I read about these CV issues, the more I appreciate my E-Z Command Controller.  I turn the knob, the loco moves...that's all I can handle at my age.  My doctor told me not to be involved with anything that might increase my blood pressure.  I didn't tell him I was a model railroader.   

Based on my experiences assisting folks with DCC for many years,  there are more DCC issues created by Operator Assume than anything else.

[Redtail67]

When taking my final examination for Locomotive Engineer...the answer to one of the questions on Train Order opreations resulted in my having a "Head On" collision about 2 miles from the switch.

The Rules Examiner asked my why I made the decision to advance to the next siding rather than clear at "Caldwell"?

I tried my best to impress this man with my knowledge of the rules and somewhere in the explanation of my actions I stated "...I assumed".

Imediately jumped up ran to the blackboard and wrote:

"ASS"   "U"  "ME"

Then stated:  "When you assume with train orders Mr. Hargrove you make an "ASS" of "U" and "ME", not to mention that you and your head end crew as well as the other trains crew are now in DEAD!

Never forgot that lesson!

Redtail67

[Midnight Flyer]

The more I read about these CV issues, the more I appreciate my E-Z Command Controller.  I turn the knob, the loco moves...that's all I can handle at my age.  My doctor told me not to be involved with anything that might increase my blood pressure.  I didn't tell him I was a model railroader.   

Great HUMOR

[Santa Fe buff]

When taking my final examination for Locomotive Engineer...the answer to one of the questions on Train Order opreations resulted in my having a "Head On" collision about 2 miles from the switch.

The Rules Examiner asked my why I made the decision to advance to the next siding rather than clear at "Caldwell"?

I tried my best to impress this man with my knowledge of the rules and somewhere in the explanation of my actions I stated "...I assumed".

Imediately jumped up ran to the blackboard and wrote:

"ASS"   "U"  "ME"

Then stated:  "When you assume with train orders Mr. Hargrove you make an "ASS" of "U" and "ME", not to mention that you and your head end crew as well as the other trains crew are now in DEAD!

Never forgot that lesson!

Redtail67

is that real?