Hi, Im installing a Digitrax DH123 into my Proto 1000 RDC Budd. I have an LED headlight, and an LED Backlight. How do I get the front and rear lights to dim with a function button?
Thanks
Charles
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Modeling the Santa Fe & Pennsylvania in HO
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I'm sure Randy will chime in, but I don't think you can do that with a 2 function decoder.
The DH123 has been discontinued, and replaced by the DH126. Still only 2 functions. The headlight, and rear light are your 2 functions, and I think to do anything more than have them on would require another function.
Mike.
My You Tube
Trainman440How do I get the front and rear lights to dim with a function button?
With a 2-function decoder you should be able to use Rule 17 lighting to dim the front and rear headlights automatically. According to the Digitrax website, the DH123 decoders come with FX3 function outputs so it may have that capability. However, if you want to control the lighting with a function button, that might require more functions. I'm sure Randy will know the answer to that.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
I don't think they offer button control of Rule 17, at least, it's not in the decoder manual nor are there any suitable options in JMRI. Only automatic Rule 17 seems to be available. TCS explicitly offers the option to have an F key do the 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.
When I tried to do this about a month ago, with a DH126, I hooked up the F1 and F2 wires, green and purple, and the CVs that I need to change were not even listed, in JMRI, so I asked about it in the Digitrax Users group, and I was told that a 2 function decoder like the DH126, would not support anything more than headlight, and rear headlight, off and on.
The green and purple wires aren't supported by a 2 function decoder. It shows that in the instructions.
I want to know more about this, so I have a ticket opened in Digitrax help desk, they open up at 8:00 am CDST, so we'll see what they say. I always get a quick response from them.
OK, I got an answer from Digitrax:
Yes you can. Set CV49 to a value of 104 and F4 will dim the front light.
That's a copy and paste right from my email from them.
I tried it, and it works. BUT, I'm using the DH126, which is the replacement for the DH123, so try it out.
I'm not sure what your question is? The DH126 is a 2 function decoder. WHy would it have CVs to support additional function output? There's physically no circuitry on the decoder to support the extra wires. The harnesses are all standard, so that's why they have green and violet wires, but the 2 function decoder has nothing connected to them. F0F and F0R, those are the two functions. There are mappings for different function KEYS but not different outputs - remember the F keys, F0-F29, have zero bearing on the physical function wires on the decoder. They can in most cases be freely mapped, plus no one so far has made a decoder with 30 function wires. 2, 4, and 6 are common for number of actual functions. The green wire may be F1, but that doesn;t mean is has to be controlled by the F1 button on your throttles.
mbinsewi OK, I got an answer from Digitrax: Dear Michael Bower, Yes you can. Set CV49 to a value of 104 and F4 will dim the front light. That's a copy and paste right from my email from them. I tried it, and it works. BUT, I'm using the DH126, which is the replacement for the DH123, so try it out. Mike.
That should also work in the DH123. I THINK a value of 120 in CV50 would then do the same for the rear light - dim when going forward, or if going in reverse, hit F4 to dim it.
rrinkerI'm not sure what your question is?
Randy, I was just trying to answer the OPs question, and, find out for myself. I didn't think that dimming could be done, as I understand it, dimming would be another function, but alas! it can be done, as per the answer from Digitrax.
Thanks.
Yeah it's no so much an extra function as 'sort of' assigning two F keys to the same function wire. It's not really doing that either, it's specialized logic in the decoder, part of what Digitrax calls the FX3 effects (which also includes things like ditch lights, flashers, Mars, Gyralite, etc).
BTW, should the case ever arise, on a decoder with more functions, you can safely connect more than one function wire to the same LED or bulb - it will light up when either or both of the functions are turned on. For example, say you have lights A, B, and C in the loco. A and B are independent, but you want C on if A or B is on, bt never by itself. Blue wire is the common like always, but then you cna connect C to BOTH A and B, no programming required.
I think what you just described is the way I run ditch lights, which are connected to the headlight, but not with the rear headlight, where A is the headlight, B is the rear headlight, and C is the ditch lights.
And since they are connected to the headlight, the loco I just tested the dimming affect on, they also dim, which is fine.
Thanks everyone, IT WORKED!
for future reference,
CV49 = 104
CV 50 = 120
Great, it worked on my DH126 too. If you use Digitrax, check out their web site, lots of info, and a great help desk.
You have to set up a login for the help desk, but usually get a response with in an hour or less.
There is also a good Digitrax User group at:
https://groups.io/
They just recently moved from Yahoo to here.