Digitrax CV Settings puzzling

Model Railroader Electronics and DCC
1

OK I admit it. I am not good at puzzles. And that is what I have when I look at the Digitrax manual. I work best with examples.

I have got another DZ123 installed in yet another Spectrum H16-44 and it works fine (I am doing 6 of these identical units for my layout this week).

I want both lights to be on when in motion, but bright in forward and dim at the non-directional end of the loco. I thought this was what the manual said for Rule 17 lighting. But when I set the CV 49 and 50 to value 8, I get on in one direction and off at the other end of the loco.

I someone could point me in the right direction of programming the CV for dim opposite direction of travel I would probably be able to see where this is explained in the manual.

Thanks in advance for any help.

2

Try CV49 = 104, CV50 = 120

To understand why/what/where/how [banghead], you need both the Decoder instructions and the Mobile Decoder manual.

http://www.digitrax.com/ftp/decodermanual.pdf

He’s right!.. (104) I goofed.

3

I’m seeing CV49=104, CV50=120…

4

Ok, thanks for the values. That will give me on bright in direction of travel and opposite end light on dim?

Now, where did those numbers come from? I am looking at the tables IVb and IVc in the manual and trying to see how you built up the answer to 104 and 120. If you have a minute, where did each digit in the answer come from on the table?

Thanks again. I am reading, but not making much headway.

5

The quick and easy cheating way is on page 43. It’s a ditch light example, but you won’t have ditch lights hooked up.

By the tables:

From Table IVB, an 8 give Rule 17 dimming. That’s which effect will be active.

From Table IVC, a 6x (in hex) is a forward ditch light, or Rule 17 dimming, a 7x is the rear. That is how the effect will work.

So, on CV 49 you have 8 plus 16x6 =104.

CV50, 8 plus 16x7=120

If this isn’t a lot of fun. download Decoderpro, http://jmri.sourceforge.net/download/

install it, and set it up to use the Loconet simulator. The nfollow the directions, and it can do a lot of the work for you.

6

… And I did it backwards. I started with DecoderPro to get a grasp and then checked it up in the book to verify and understand what was required.

But even with this I read 104 but typed 108 in the original post. [:-^] What can I say…

7

When I first got a Digitrax decoder, I just kept entering numbers in CV 49 and 50 until I found 104 and 120 did what I wanted. [D)]

Especially now that TCS decoders have Back EMF, I doubt I’ll ever buy a Digitrax decoder again - TCS is MUCH easier to work with, the little fold-out that comes with the decoder explains exactly how to calculate what to put in each CV to get the result you want.

8

Thanks for the lesson, fellows. I haven’t learned the x6-ing and x7-ing reading of the values and hex has another meaning for me just now. That is the starting point, it looks like. I also have decoder pro installed, but haven’t yet got to using it at all.

Just now, I am converting all these H16-44s one after the other, plopping them on the track to check them out, and thought I would see about the lighting. I could wait until I have learned the decoder pro routines then copy the settings over from one to the others I guess.

9

Take the time to learn decoder pro, and you won’t have to understand hex, or any of that stuff. I’ve worked with it for years, so it is second nature to me. But take advantage of the tools you have!

10

DEC, HEX, BIN is not the end of the world. Most Digitrax tables give you both values. Also Windows calculator can be setup for standard or scientific. In scientific you get DEC, HEX, BIN conversions a mouse click away.

But if you take the time to work with DecoderPro, it will all fade away.

11

I want to do the Rule 17 headlight thing too. If I’m reading this right all I have to do is (on the programming track) go to those CV values and adjust them to what it says. Then I’ll have a dim light trailing and bright leading? Will it dim (leading side) if I stop but don’t change direction?