I realize that some decoders will many more CV#s in use than others, but do the basic functions have the same CV # regardless of the manufacturer? If so, I'm sure I can find a list on line, and quit pestering you folks with a lot of my novice questions.
My only DC equipped loco is an On30 Bachmann Davenport which came new with DCC installed. I bought it mainly to get started in DCC. I knew it was pretty much bottom of the line, but I was surprised it came with almost no info about the decoder. I asked "The Bach-Man" a few days ago, but no answer yet, except:
"I'll ask tomorrow, but I expect they're the standard decoder cvs." That lead me to believe there might be a universal standard. Thanks.
- Harry
Here you are, the PDF with the instructions for the basic decoder that B-mann equips their loco´s with:
PDF manual
I hope it will help.
Regards; Michael.
Swedish Custom painter and model maker. My Website:
My Railroad
My Youtube:
Graff´s channel
Harry,
Some CV's are Mandatory, some are optional. Some more can be assigned by the manufacturer of the decoder.
All NMRA compliant decoders will have the mandatory CV's. The optional CV's are exactly that. The CV will always be for that function but it's up to the manufacturer to include it or not. The NMRA CV list can be found here.
Martin Myers
Loys Toys did a pretty good job of explaining CVs and the NMRA standard.
http://www.loystoys.com/info/configuration-variables.html
Hope this helps.
Rich
Alton Junction
Two common ones that the low-level Bachmann decoders don't have are CV 5 and 6, which control top speed and midrange speed respectively. These allow you to limit the engine's top speed, so say an industrial switcher like yours might be set so even at "full power" it's only going say 10-15 MPH.
Though not a standard, I find decoders with Back EMF are nice. They have an automatic "cruise control" so if you have an engine running at say 15 MPH it will apply more power or less power to the motor so it keeps running at that constant speed, whether going uphill or downhill.
No, there is no universal standard. There are conventions put forth by the NMRA, but some decoders are not fully compliant, nor are they all capable of doing all the things all similar decoders do across the manufacturers. For example, the ESU LokSound decoders don't have the same CV's doing a given process as do the Soundtraxx Tsunami decoders, and the same applies for the QSI's. Your Bachmann engine is probably loaded with a 'stripped' Tsunami which has unique characteristics. There are recent threads here where this is explained. If you do a search under "Search our community" to the right, and probably lower on this page, you will probably come up with several.
-Crandell
Thanks everyone. All of your replies are very helpful. I'm gonna fool around a little with my decoder and see if I can get the hang of it.
Crandell, I assume the basic functions (i.e. CV #1 = address) are the same for all NMRA decoders - is that correct?
HarryHotspur I assume the basic functions (i.e. CV #1 = address) are the same for all NMRA decoders - is that correct?
I assume the basic functions (i.e. CV #1 = address) are the same for all NMRA decoders - is that correct?
I think the answer to this is yes and no. If the decoder is NMRA compliant the basic configuration variable numbers should be as shown at the following link: http://www.nmra.com/standards/DCC/standards_rps/RP-9.2.2%202007%20July.pdf
Note that this is similar to the link mfm37 posted above, except this is a later revision. If you look at the table in the link, you'll see that there are only 3 or 4 CVs that are mandatory. Then there are 4 that are recommended. Finally there are a bunch that are optional. So, as I understand it, for a decoder to be compliant all it needs to have are the mandatory CVs. So far as the CV values go, the only value that the NMRA defines as mandatory is a value of 3 in CV 1.
Even though the CV numbers (or really definitions) might be the same from decoder to decoder, the different decoder manufacturers might define a different value or range of values that can be entered into each CV. The only way you know what CVs the decoder supports, and the values that each CV will accept, is to have a copy of the decoder instructions available to you.
Graffen posted a link to the decoder instructions that he believes are appropriate to the decoder installed in your engine. If you look at that link it appears that there are about 13 CVs supported by the decoder, and in most cases either the range of acceptable values or the factory default value is listed.
CV 3 is an example of a CV that can have a different range from decoder to decoder. The default value is 3, but the CV will accept values between 1 and 99. However, some DCC systems will allow a short address between 1 and 127. So if you happen to have one of these other systems, and for some reason want your loco to have a short address of 105, you can sit there all day long trying to program CV1 to 105 and not get anywhere.
Thanks, maxman. Great explanation. I think I'm getting there.