Hi all,
I know these decoders don't have the greatest reputation, but -- well, I've got two of them, set to go into two identical locos, which makes speed matching for MU use much easier. I've spent a week and a half trying to get a Digitrax decoder to match the Atlas -- it's been a headache, and the vague Digitrax manual has me ready to slam my head against a wall...
Anyhoo...
My big problem lies with trying to add some lighting effects to both the front and rear outputs. I'm going by the manual as far as I can tell; enabling dimming, dialing in a dimming effect ... but nothing happens. Headlamps function, but there's no effect -- no mars light, no strobe, no anything I try to dial in.
Anyone know what's going on here? Has anyone been able to successfully program these features in the Atlas HO DMD?
Wondering if it's an issue with the golden white LEDs that were included with these locos, but then again, effects seemed to work okay when I tried installing a Digitrax decoder. I just don't want to spend more money on another decoder, and I sure don't want to try delving through that manual again (fun fact: found half the values for lighting effects listed in the manual bore no correlation to what the loco actually did; had to keep playing by ear until I found what I wanted...).
Thanks for the help -- can't wait to get a pair of Alcos up and running on my road!
-Evan
Your speed matchign problems start with the fact that the Atlas decoder, unliek the Digitrax, does not support all 3 basic speed CVs - CV2 for start voltage, CV5 for top speed, and CV6 for mid throttle speed.
I've never found the light CV values to be off int he Digitrax manual - which manual are you looking at, the full Decoder manual? That has information for ALL Digitrax decoders, including older ones that didn;t have as many lighting effects - so you need to pay attention to which table you are looking it. One is for the older FX decoders, the other is for the newer FX3 decoders. They aren;t the same, and there are at least twice as many options for the FX3 decoders.
Third thing, they do NOT have to be perfect. There's this idea goign around that if you don't make a pair of DCC locos run EXACTLY the same, you will burn on up. Hogwash! Now if one goes 30smph on speed step 10 and the other one goes 60 at the same speed step, it won;t be very smooth and one will be pushing or pulling the othr the whole time. But if they are close it will be fine. And they will get better with a long train behind them, speed matching under a no-load condition doesn;t really prove much.
FOurth, if one is a Digitrax decoder and the other is an Atlas, depending on which Digitrax decoder youa re using, you are dealign with one BEMF decoder and one without. If it's a Digitrax decoder with BEMF, turn it off. CV57=0. It will be easier to match this way.
Fifth, there's nothign to devle through any manual for. SPeed matchign uses the same CVs on ALL brands of decoders. Start with gettign both locos to start up at the same speed step. If one moves on speed step 1 and the other doesn't, increase CV2 until the second one also moves. If one is faster on speed step 1 than another, increase CV2 on the slower one until they are close. DO the same at full throttle, using CV5. In this case adjust CV5 on the faster one to slow it down - you can;t make the slower one go any faster than full throttle. Once they are the same at start and maximum throttle, you cna play with CV6 to adjust the midpoints - or at least adjust the Digitrax one so it runs the same speed at 50% throttle as the Atlas one. This is a time when you really want to be using Ops Mode or Programming on the Main to adjust things - the changes take effect instantly while the locos are moving. That's all there is too it - the rest is just lather, rinse, repeat until you get the speeds close.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Regarding the lighting effects problem, I'm afraid you won't be able to get the lighting effects to function properly with LEDs. These older decoders were used when the engines still used bulbs and would handle the effects. I fought with the same issue at one time. I installed bulbs and they would dim and exhibit all the effects just fine .... put the LEDs in - and nothing, just constant on.
LEDs require an extremely low output to simulate dimming (and other) effects that these older decoders won't support. Even early versions of TCS decoders had this problem as well.
Your only option for the effects to be visible is to either go back to bulbs or purchase a newer decoder that supports LEDs.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
rrinker Your speed matchign problems start with the fact that the Atlas decoder, unliek the Digitrax, does not support all 3 basic speed CVs - CV2 for start voltage, CV5 for top speed, and CV6 for mid throttle speed. I've never found the light CV values to be off int he Digitrax manual - which manual are you looking at, the full Decoder manual? That has information for ALL Digitrax decoders, including older ones that didn;t have as many lighting effects - so you need to pay attention to which table you are looking it. One is for the older FX decoders, the other is for the newer FX3 decoders. They aren;t the same, and there are at least twice as many options for the FX3 decoders. --Randy
I'm looking at the decoder manual that came with my Zephyr -- and I am looking at the FX3 effects table both in the manual and online, as my DT decoder is an FX3 model. Noted a number of discrepancies, including the strobes (single pulse responds to x6, not x4; double pulse responds to x7, not x5) and a few other effects. I imagine I'm doing something wrong somewhere, but everything else worked as anticipated (with some help from the DT tech staff, of course).
Appreciate the ideas -- may just try swapping out some bulbs into the Atlas and see if it changes anything for the better. I'll try and use some of my holiday to really school myself on the intricacies of DCC...
Interesting - I don't use anything more than Rule 17 lighting for my prototype, and even that's pushing it for the era I model, but naturally when I first got my stuff I had to try it all out to see what the different effects were like, and they all seemed to be exactly as listed int he manual. The loco I tried all this on had regular bulbs for lights though. Digitrax doesn't do LEDs too well - in general with flashing effects they don't dim or don't dim enough depending on the resistor, so when the effect needs the light to be dim - it isn't dim. My testing was done with a DH163 series decoder, I don;t have any newer ones as I use pretty much only TCS decoders these days. I tried some of their effects with LEDs and, with proper adjustment of CV64 for dimmed brightness to handle LEDs, they work well. Best I've seen for doing effects with LEDs, NCE decoders are a close second. It's worth the effort to use LEDs when at all possible, especially in tight spaces that aren't easy to get to - you'll only ever had to do it ONCE, they'll never burn out in your lifetime unless you mess up the wiring, in which case they'll burn out pretty much instantly.