CV 29

[maxman]

mreagant

Is there any disadvantage to doing that even though I won't be running it on a DC?

There have been instances of misbehavior of locos ( i.e. running away) if the analog operation (DC) is not disabled.  General recommendation for non-DC users is to disable.

[mreagant]

I get the joke--I have a math degree.  However, I'm not sure I understand why it is necessary to calculate a value when the manual provides a table of values for CV 29 that explain the results of entering a specific value.  Sort of like refining your own crude oil to get gasoline for your car  The reason I asked the question was that I wasn't certain if 51 would have other effects beyond the change of direction that would matter.  I now see that 35 is a better mix of what I need.   Actually, the default is 6 so adding 1 would change the direction and leave DC operation ON.  Is there any disadvantage to doing that even though I won't be running it on a DC?

Thanks for all your help.

Mike

 

[MisterBeasley]

betamax

Since it is bit 0, a value of 1 is added to the value currently in CV29 to change that.

Remember, there are 10 kinds of people in the world - those who understand binary arithmetic, and those who don't.

If you don't get the joke, use the calculator that Randy pointed out.  Strictly speaking, you don't want to "add" 1.  You want to toggle just that bit, so if it's already 1, you need to subtract 1 or you will alter a different bit.  I think the default value of NDOT is zero, so normally adding would be the correct operation.

[richhotrain]

mreagant

I've just installed a Digitraxx 163PS.

The on-line manual table for CV 29 settings seems to say that a value of 51 will reverse that direction as well as disable DC operation.

Have I read this correctly or is there another/different setting to get  a short hood forward setting for forward?

Mike,

The correct designation is Digitrax DH163PS.

For DC Operation Off and 28/128 Speed Steps:

34=Forward
35=Reverse

So as Randy indicated, the CV29 setting should be 35 in your case.

A CV29 value of 51 is for a 28/128 Speed Table setting.

Rich

[betamax]

There is a setting called NDOT that sets direction of travel.

It is within the CV29 group. Since it is bit 0, a value of 1 is added to the value currently in CV29 to change that.

[rrinker]

 If you are using the 28 step speed table it is. If you are not using a speed table, the correct setting is 35 for long address, no DC, reverse normal direction of travel.

This handy calculator is useful: http://www.2mm.org.uk/articles/cv29%20calculator.htm

        --Randy

 

[mreagant]

I've just installed a Digitraxx 163PS in a P2K SD7 and because the DCC plug is on the far end of the board from the cab I have to plug it in so that the decoder lays over the board  toward the cab. That sets the forward direction for the long hood.  The on-line manual table for CV 29 settings seems to say that a value of 51 will reverse that direction as well as disable DC operation.

Have I read this correctly or is there another/different setting to get  a short hood forward setting for forward?

Thanks

Mike