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CV codes

Started by renegade800, February 24, 2012, 06:58:34 PM

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renegade800

where can I find a list of CV codes and associated values for my Dynamis dcc system?  I have the Pro box and can read the values but I dont know what the correct values should be.  Before I got the Pro box, I couldn't resist changing some of the codes to see what they would do and now I have problems.  I have the Kato brand BNSF engines and they have the digitrax decoders and the manual with the Pro box doesn't help at all.  Anyone know where I can find a list of these CV's and values?

Thanks

Rick

richg

Download the manual for the decoders. Go to the Digitrax site. Don't know if the factory equipped locos have the same CV's as a decoder you install yourself.
The Dynamis manual might be some help but there are some differences depending on the manufacturer of the decoder. The Dynamis manual is in the Bachmann site here.
There is a learning curve. Many times just doing a decoder reset and starting over helps a lot.

Rich

jward

you will want to look for the mobile decoder manual on the digitrax web site. the literature which comes with the decoder is just a basic overview. the manual on the web has the full scope of cv's available. 
Jeffery S Ward Sr
Pittsburgh, PA

renegade800

do you need to know any specific number of the decoder installed or are the cv values the same for all digitrix decoders?  Two of my engines came dcc equiped with sound, two dcc equiped without sound and my other two engines were dcc ready and I installed the decoders  The main problem I am having is with the speed control.  My first two egines that I installed the decoders run at a much higher speed than the two that came dcc and sound equipped and I want to slow down the first two to try to match the others so I can put them in a consist.

jward

that sound like a simple adjustment of cv's 2 5 & 6. those 3 values control the start max and mid range voltages. whatever numbers they are set for, try lowering them until they match your other locos.
Jeffery S Ward Sr
Pittsburgh, PA

Len

DCC Standards & Recommended Practices are available on the NMRA web site at:

http://www.nmra.org/standards/DCC/standards_rps/DCCStds.html

CV's are listed in RP-9.2.2, which is available as an HTML web page or downloadable as a .pdf file.

The RP tells you which CV's are NMRA required, available for manufacturer specific use, etc.

Len
If at first you don't succeed, throw it in the spare parts box.

Doneldon

Renegade-

Just to be picky -- there aren't any "CV codes" in your Dynamis system; the CVs and their values are contained within the decoders. Your Dynamis, or most other DCC system, can change the CV values and in many cases read them. Your system will "remember" a few things like engine number or some consisting data, but your command station is a controller, not a memory bank.
                                                                                         -- D

renegade800

I guess I knew that the command station doesnt have any values and that it is just used to send commands to the decoders.  I went to Digitrax site and looked up the different decoders, it appears that most of the decoders use the same values for each CV.  Being fairly ignorant about dcc I wish the manuals were written for those like me that are new to dcc.  The more I read I am starting to pick up on some of it.  Some of the stuff I have read gives a value for a specific CV and I understand that.  What I need to know is what is the range of values for the lower CVs that control speed and does the lower the number slow it down or not.  Do the CV values change if you use a 28 step speed vs a 128 step speed.  My other concern is with Digitrax decoders and the CV values listed, ie: a value listed by Digitrax is 008, with the Dynamis you cant enter 008 only the number 8, does that do the same thing?

jward

for the speed control cv's in the decoders, the values range from 0 to 255. these tell the decoder what voltage to apply. cv2 you want to program low, so that the locomotive just barely starts to move when you crack the throttle.
cv5 is max voltage. you want the value here to be less than 255.

the way i set this cv is simple: set the locomotive to the speed you want, then note what speed step it is on. or in the case of a knob type controller, note how far the knob is turned. subtract the value you programmed for cv2 from 255. divide this number by the number of speed steps (usually 28 or 128) then multiply that number by the number of the speed step you want. this will give you the approximate value to program in cv5. for knob type throttles like the digitrax zephyr, 255-cv2 times the percentage of throttle arc used to obtain the desired speed.

say the throttle is open about 2/3. the formula would be 255 -cv2 x 0.66= desired top speed.

cv6 is mid range voltage. it should be between cv2 and cv5, but where is determined by how you want the locomotive to run. if you want it to accelerate quickly to cruising speed, set cv5 high, above the halfway mark between cv2 and cv5. if you want slower acceleration, to simulate starting heavy trains, set cv6 low. in no case should cv5 be higher than cv5, or lower than cv2.



Jeffery S Ward Sr
Pittsburgh, PA

renegade800

jward

I appreciate the explanation, I think I am starting to grasp the idea of how the values work.  I know I need to do some experimenting and I think I will write down everything I change so I can return to them if the result is not what I want.I have been trying to read up on dcc and decoders and I am starting to pull a lot less hair out.  Again thanks for the help

Rick

blf

Sometime ago, I down loaded some CV lists that had blank areas behind each number so you could write in the values you had set. If you changed something later you could erase and enter the new value. This was done especially so if I had to do a reset I could reenter the values I lost. Each engine had its own chart.Kept a master copy of the different products so I could make as many new copy's as needed. Don't remember where, but was either learning about QSI or Blueline at the time. Bill

Rangerover1944

#11
I too had a lot of difficulty when I first attempted to play with the CV's. The first and most important thing to do was to experiment, and I was as eager as you. Most guys are reluctant to even try to change cv's, afraid of messing it up and destroy the decoder or losing the factory settings. The documentation that comes with the decoder is very important like what's been said. However to keep track of all the cv's, I found a simple solution it's called JMRI/decoder pro. It keeps track of all the cv changes I have made on each individual loco, it keeps a roster of all the loco's I've entered, right now about 35 entries. If I have the same decoder in a different loco and it runs great the way I programmed the cv's, I bring up the page on my roster with for instance #16, the roster entry for the loco I aready reprogrammed the cv's to, then I put the new loco entry #36 on the programme track, add the new loco to my roster, return to the programme for #16 and hit the button "write changes on sheets", and it's done. I don't have to go through all the cv's in order to change each individual one, maybe just a little fine tuning when I test on the the layout. I don't have to remember what changes I made or write them on scraps of paper with crossed out entries, not knowing for sure what I did. With the hit of the button I can go back to a loco I entered 5 years ago and see what I did. The JMRI software is free, the digitrax decoder pro 3 interface cost about $75.00 and money well spent. And MUing with decoder pro is the best I ever used for programming to the same speeds, it's simple and easy.
Introduction to Decoder Pro http://vps880.inmotionhosting.com/~modelt5/assets/video/mrh/JMRI/DecoderPro1_player.swf
JMRI download page
http://jmri.sourceforge.net/download/