Well, I'm stumped. The digitrax manual says for a dimmable light enter a value of 8 as the second digit of CV 49. I'm thinking that the function must be programmed to be on in forward and reverse, so the first digit would be 2, which means the hex CV programmed would be 28. I am using a powercab and quickly found my mistake, or so I thought. I was entering the number 28 which was hex. A quick conversion told me I should enter 40 into CV 49. It just acts like a normal headlight and wont dim. What am I doing wrong?
The 2 in the first hex digit is for NON DIRECTIONAL lighting. Continue down a little bit int he table and you'll see first digit of 6 is for 'Special Logic for Fwd Ditch Light or Rule 17 dimming'
The 8 for the second digit is correct, so what you want is x68 hex or 104. If there's a rear light hooked up to F0R and you want the same effect, you put x78 hex or 120 in CV50.
In fact if you move one page further on in the decoder manual, page 43 gives exactly the example of setting up the forward and reverse lights for Rule 17 dimming.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I looked at the online documentation, and it says to set bit 8 of CV 49 for the front headlight, and CV 50 for the rear headlight. Bits count from the right side, so you want 256 decimal or 100 hex in those words.
EDIT: I see Randy has a different answer. While I was typing mine, I thought of the thread about how confusing the Digitrax manuals were.
So, try them both and let us know if either of us figured this out.
It takes an iron man to play with a toy iron horse.
Awesome, I got it working now, thanks! Guess I should have printed page 43 also... I only printed pages 39-42, oops. Thanks again!
MisterBeasley I looked at the online documentation, and it says to set bit 8 of CV 49 for the front headlight, and CV 50 for the rear headlight. Bits count from the right side, so you want 256 decimal or 100 hex in those words. EDIT: I see Randy has a different answer. While I was typing mine, I thought of the thread about how confusing the Digitrax manuals were. So, try them both and let us know if either of us figured this out.
Guarantee it's 104 for the front and 120 for the rear. 68 and 78 in hex. It's not really confusing at all. Not sure where you're seeing the bit maps for CV49 and 50, I'm looking at the decoder manual and all they ahev is the hex table. Plus I know another reason it can't be x100 hex. You can;t put x100 hex in a single 8 bit value. The maximum number 8 bits can hold is 255.
And I was typing my response while you were posting, Mr. Beasley. setting CV 49 to 104 worked. The effect I'm setting up is a Mars light and a headlight on an F7. I wanted the headlight dim in reverse. I somehow managed to get the mars light working by myself.