# 2, 4, 6, 8 - that's when lights are really great!



## JackM (Jul 29, 2008)

I finally got the speaker in my RDC-3 baffled reasonably well, the Titan card operating, etc. But the headlights and marker lights are acting kinda weird.

At first I thought they were just flashing randomly but then I slowed down the way I adjusted the speed wheel on my NCE controller and noticed that the lights are on only when the speed is an even number. The lights are off when the speed is an odd number.

Since everything else is working properly, I'm guessing I unintentionally set a CV to some oddball number. Although I have some understanding of CVs, I am still somewhat intimidated by them. Can anyone direct me to what the heck is causing the odd-even lights? (I don't remember setting any CVs at all.)

JackM

Kinda fun to watch, but not very prototypical.


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## gswartz (Jan 9, 2008)

I remember reading of a similar incident recently and I believe it has to do with your decoder being set for 14 speed steps rather than 28. Others might chime in and correct me if I'm wrong, and I'll go see if I can find the thread with the similar issue, but check to see what CV29 is set to.


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## Treeman (Jan 6, 2008)

Speed steps not matching is a common problem that makes lights do funny things. Just make sure decoder is set correctly to match your setup.


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## ntpntpntp (Jan 14, 2008)

If I remember correctly, under the 14 speed step protocol the headlight flag is sent as a separate bit within the same byte as the speed value, whereas in 28 speed steps and above the headlight control is a separate command. Therefore if your DCC command station sends 28 step speed commands to a decoder that's expecting 14 steps, the decoder sees the "extra" speed bits as headlight commands and turns the headlights on and off as you move through the speed steps on your throttle.


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## JackM (Jul 29, 2008)

The good news is I got it all working without the even/odd stuff. The bad news is I'm not sure what I did. 

CV29 was zero. I think I tried to set it to 28 but the voice said zero again. I suspect 28 is not the number CV29 needed in order to set to 28 That'd be way too easy. 

Based on a lot of experience, I think there's a 50/50 chance I mess it up again. So if anyone can find that thread I'm sure I'd benefit from it. I don't seem to recall ever hearing about 14 steps, just 28 and 128 

Thanks! 

JackM 

So much knowledge, so little gray matter.


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## Treeman (Jan 6, 2008)

LGB's, MTS used 14 speed steps.


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## Dan Pierce (Jan 2, 2008)

While LGB used 14 speed steps, many of there decoders will do 28 and some 128 steps. 
Check the revision by reading cv7 and cv 106. CV 7 is the rev, cv106 further defines the decoder and is in the massoth list for the softwate on the 55045 computer interface. 
For dc/analog and 28 step operation, CV29 must be a 6. a 4 would be DC and 14 steps. Add 32 for extended addressing.


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