Hello!
I just set up an Athearn ALCO PA blue box loco with a Digitrax DH123 decoder. The shell has a mars light set up. I ran a LED to the white wire and one to the yellow wire. My question is with coding. I can't get LED on the yellow wire to stay on when the loco is running in the forward direction. Do I need to put a different decoder in or is there a way to remap this guy up for Mars lighting?
Kenny,
The DH123 is only a 2-function decoder so all you will get is front and rear headlights. (That's what the middle "2" stands for.) If you want Mars lighting, you'll need at least a 4- or 6-function decoder.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
From the Digitrax Tech support Depot
http://ikm.digitrax.com/questions.php?questionid=371
Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum
You'll need a decoder with at least 3 functions - the white and yellow wires for F0 are generally not remappable on most any decoders, so you need at least one more function wire to use for the Mars light.
If cost is the primary factor, the NCE D13SRJ is functionally equivalent to the DH123 except is had 4 function outputs and works better with LEDs (Digitrax decoders don;t do flashing and blinking very well with LEDs). If you didn;t clip off the green and purple wires from the plug, you can just unplug the DH123 and plug in the D13SRJ.
To move up to more features like BEMF, the TCS T4 Xis a better option than the DH163, both for better LED operation and a better BEMF implementation.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
If this decoder does support mapping of the light functions, you can re-map the rear headlight function using CV 34. It is normally set to 2, which programs it to be on when the engine is in reverse. You could re-map it to Function 1 by setting CV 34 to 4, Function 2 by setting it to 8, Function 3 with 16 and so on up to Function 6 at 128. The light will just be on, not blinking or strobing, but that's the limit of the decoder.
It takes an iron man to play with a toy iron horse.
So I switched out decoders to an SD164D. I have a beacon light that I put on top of the cab (yellow wire) and two 5mm LED's (one on the white wire, one on the purple wire). They all light up but I'm still confused about remapping the CVs so the purple is a forward direction Mars light and the yellow is non-directional beacon. I guess I'm better at soldering and wiring than I am at reading the Digitrax manual! Since this is a sound decoder also, when I press F2, the horn blasts and the purple light light up? I guess my question is remapping CV 50 and 52.
You need to modify CV52 for the Mars Light effect, since that is the CV that controls the purple wire. So first you set the effect on the wire, then you cna change the wire to be controlled by a different function key. And you'll probbaly want to put the beacon on the green wire, not the yellow, so that it can be made independent of the headlight direction. There isn't an option for "always on" so it will have to be tied to coming on when you turn the headlight on. Or tied to some other function key not used for the sounds.
Default green wire is F1, for a beacon you set CV51 to 38, then you will get a rotary becaon effect when F1 is on, regardless of direction.
Default for the purple wire is F2, for a Mars light, set CV52 to 34. This will give you a Mars light effect on the purple wire with F2 is on, regardless of direction.
Now that the effects are set, there's the issue of which button controls things. F1 is the bell sound and F2 is the whistle, AND F2 is momentary, so it's not so great at controlling any lighhting other than maybe ditch lights which flash when the horn is sounded.
CV33 controls the forward headlight, CV34 controls the rear headlight. If you make CV33 13, the white, green, and violet wires will all be on when F0 is on, goign forward. If you set CV34 to 14, then the headlight will go out in reverse, but the green and violet will stay on.
JMRI will make this all easier to do, since you cna select from dropdown boxes and check boxes instead of deciphering the tables int he Digitrax Decoder Manual - you need to look in there to find this stuff, the sheet that comes with the decoder does not have all this information, typically they give an example with Rule 17 headlights and ditch lights.
Thanks Randy! I don't have a PR3 (yet!-wife got me a gift certificate to the hobbyshop!) I'll switch the beacon over to the green wire and start futzing with the cv's to get them to work. Liked you pics on your website- Looks like you live in my neck of the woods!