Remapping lights Digitrax

[trainforfun]

Hi guys
would like to remap the rear headlight wire ( yellow ) to the front headlight . ( white wire is damage )
What would be the value of CV29 or CV49 to get that ?
I use JMRI to program CV .

Facts :
Digitrax DZ126 decoder
I use the normal direction of travel .
128 steps
4 digits address

I don't feel to go thru a pile of Digitrax books to get the answer ...
I know Pete you don't like Digitrax but this is what I have !!!!

Thanks

[trainforfun]

Found it !

CV33 = 2
CV34 = 1

Change front to rear and rear to front .

[peteski]

Self-solved. Nice!

Remember, few years from now, if you have to reset the decoder for some reason, you will be wondering why the headlight stopped working. Unless you are using JMRI to store your decoder settings or make a note somewhere (like inside the locos). 

[tehachapifan]

Also, in case you are not already aware, Digitrax has a pretty handy CV calculator at:

http://www.digitrax.com/support/cv/calculators/

It may still take some time to fugure out how to use it sometimes.

[trainforfun]

Self-solved. Nice!

Remember, few years from now, if you have to reset the decoder for some reason, you will be wondering why the headlight stopped working. Unless you are using JMRI to store your decoder settings or make a note somewhere (like inside the locos). 

I always make a sheet describing everything I did whan modifying a loco or reprogramming .
Very handy for some locos that are normally working in reverse than some others .
A case like this one with the white wire not working or worst fou finish the decoder installation and you realize the motor was installed upside down ...
Instead of reworking the wires you just reprogram !!

[trainforfun]

Also, in case you are not already aware, Digitrax has a pretty handy CV calculator at:

http://www.digitrax.com/support/cv/calculators/

It may still take some time to fugure out how to use it sometimes.

Wow this is great I didn't know they had that !

[peteski]

I always make a sheet describing everything I did whan modifying a loco or reprogramming .
Very handy for some locos that are normally working in reverse than some others .
A case like this one with the white wire not working or worst fou finish the decoder installation and you realize the motor was installed upside down ...
Instead of reworking the wires you just reprogram !!

See, I would much rather rewire the motor (or even fix the broken wire).  But I also realize we all have different priorities and different skills.

And what you mentioned about using CV to reverse the motor direction is a common misconception which for some reason doesn't seem to die out.

The "direction" bit you are talking about in CV29 does not only reverse the motor - it also reverses the headlight direction. It is not useful when only the motor is miswired. It would be useful if the entire decoder was installed backwards.

What the direction bit is really designed for is when the model has a plug-n-play decoder installed (which means that the orientation of the decoder is fixed) but the specific loco ran reverse from the established forward direction. For example, some railroads ran hood diesels long-hood forward.  That would be a perfect reason to set the direction bit in CV29.

[trainforfun]

The other problem is some model locomotives are designed with the brushes at the rear and some with the brushes up front . So when they built the model they turned the motor 180¤ lenghtwise to fit with other models .

That mean the orange and grey wires that connect the brushes have to be reversed to keep the loco going in the same direction shown on your throttle ...

When everything is done and working and I realize the engine is not working in the right direction I don't feel to reopen it and turn the motor 180¤ lenght wise .

Much easier to change the setting ( motor and lights )  , specially if you use JMRI on the computer , and keep track of the change .

[peteski]

The other problem is some model locomotives are designed with the brushes at the rear and some with the brushes up front . So when they built the model they turned the motor 180¤ lenghtwise to fit with other models .

That mean the orange and grey wires that connect the brushes have to be reversed to keep the loco going in the same direction shown on your throttle ...

When everything is done and working and I realize the engine is not working in the right direction I don't feel to reopen it and turn the motor 180¤ lenght wise .

Much easier to change the setting ( motor and lights )  , specially if you use JMRI on the computer , and keep track of the change .

The location of the brushes is not relevant. Rotating the motor 180 degrees would change its direction (in the original DC powered model).  Unless the manufacturer made a mistake, every DC model (regardless of the motor orientation in the chassis) is designed to go "forward" when the right rail has positive voltage on it.  The plug-n-play light-board replacement decoders also have front and rear.  If you flip the direction bit in CV29 on those decoders then the headlights and motor will  be reversed.   Of course you can further confuse things by remapping headlights  (F0F and F0R) to further confuse customize the install.  But at that point you would have accomplished the goal of virtually flipping the motor's polarity.  Hey, it is your model - whatever works for you.

[nickelplate759]

See, I would much rather rewire the motor (or even fix the broken wire).  But I also realize we all have different priorities and different skills.

And what you mentioned about using CV to reverse the motor direction is a common misconception which for some reason doesn't seem to die out.

The "direction" bit you are talking about in CV29 does not only reverse the motor - it also reverses the headlight direction. It is not useful when only the motor is miswired. It would be useful if the entire decoder was installed backwards.

What the direction bit is really designed for is when the model has a plug-n-play decoder installed (which means that the orientation of the decoder is fixed) but the specific loco ran reverse from the established forward direction. For example, some railroads ran hood diesels long-hood forward.  That would be a perfect reason to set the direction bit in CV29.

So, I somehow wired the motor backwards on an install of a TCS M4 tonight.  Fixing that isn't easy (cause I would have to splice wires or solder in the middle of the board which I'm bad at).    The direction bit in CV29 is not the solution, just as Pete says.  Is there a programming solution? to this screw-up?

<edit>  RTFM  Yes there is!

First use CV29 to reverse direction. Now the lights are backwards.
Set CV49 to 10h (16) and CV50 to 0 (any base you like).

Done!

[peteski]

So, I somehow wired the motor backwards on an install of a TCS M4 tonight.  Fixing that isn't easy (cause I would have to splice wires or solder in the middle of the board which I'm bad at).    The direction bit in CV29 is not the solution, just as Pete says.  Is there a programming solution? to this screw-up?

<edit>  RTFM  Yes there is!

First use CV29 to reverse direction. Now the lights are backwards.
Set CV49 to 10h (16) and CV50 to 0 (any base you like).

Done!

Yes, the great software fix  . . .

How about this:  most DCC throttles indicate the travel direction of your loco. Forward/Reverse (relative to the actual front of the loco, since locos do have front and back).  After this triple CV modification exercise (to fix a hardware problem), does the direction indicator on your DCC throttle show the models direction correctly or is it backwards?

[nickelplate759]

Yes,  everything shows and goes the correct direction.