Book recommendation DCC CVs?

[philiprporter]

I hope this hasn't been addressed already (but searching for DCC CVs and permutations thereof yields zillions of results!) but is there a decent book out there that covers adjustment of CVs in detail?

 

What I'm driving at is that I have recently had to adjust CVs on a Bachmann 105 to alter the brightness of the front lamps with great results, but before doing this I had to alter 'indexing CVs' (with values gained from a very helpful RMWeb post) and I really want to learn and understand more about this, as I am told that adjusting things like indexing CVs (for example) has the capacity to result in unexpected changes if you don't know what you are doing - which I don't!  

 

I'm OK with adjusting CVs to do basic things like alter master volume on a sound decoder or individual sound volume, and I understand how a CV number is made of 8 bits that are either 'on' or 'off', but I really want to understand the world of CVs more fully/in detail and how I can use them to do things like dim lights and how things like the indexing CVs work.

 

I had considered Nigel Burkin's book on the subject (A Practical Introduction to Digital Command Control), but from reviews and book overviews on websites, I can't see whether he covers CVs in detail. The same goes for other books that are available from UK and US authors. I did wonder if its a case of different decoders from different manufacturers use different CVs and in different ways so there is no 'book', but my inexperience is showing here and I don't know if this is the case or not? 

 

So in a nutshell, I want to learn more about how all this CV stuff works in detail, but I'm struggling to find a decent resource-I've looked at DCC Wiki, but when it comes to CVs it seems rather impenetrable - almost certainly reflecting my lack of intellect. 

 

Many thanks, Phil.

 

[johnd]

Have you had a look at the following website -  https://www.nmra.org/

 

After all its they who set the CVs.

[Nigelcliffe]

You won't find a book which covers it, because most CV's are "up to the manufacturers".   Some things are standard, a few things are recommended (though makers don't necessarily follow the recommendations), and the rest are totally up to the manufacturer. 

 

What you describe on index CV's is, in a UK context, probably an ESU decoder.  They have the most complex CV structure of any decoder, but it offers a lot of capabilities to set things, and control what happens. 

 

So, given its unique per manufacturer,  you're reduced to working through the manufacturer's manuals, slowly putting together what you think may be happening.

 

 

For most things, I'd point people at JMRI/DecoderPro, which is free software, which runs on Windows, MacOS and Linux.   It interfaces with many DCC systems, so the computer can issue commands to the DCC system, including decoder programming.   That offers programming of many thousands of decoders, including the really complicated ones such as ESU (where the software correctly sets the indexing, then unsets it when finished).     Once setup and the basics are understood, its probably easier for most people than punching multiple numbers into a handset to change a single parameter. 

 

 

 

- Nigel

 

 

 

[JimFin]

1 hour ago, Nigelcliffe said:

You won't find a book which covers it, because most CV's are "up to the manufacturers".   Some things are standard, a few things are recommended (though makers don't necessarily follow the recommendations), and the rest are totally up to the manufacturer. 

 

 

I would agree with that thought. My understanding is that the NMRA tables indicate the required end result for a specific CV value but it is up to individual manufacturers how they achieve that result.

 

As is often the case with software, there can be many ways to achieve a specific end result, some more elegant than others, some more robust than others but to understand how a specific decoder achieves a specific end result  would mean going into the manufacturers source code and reverse engineering it since I suspect they would all decline to give you access to their intellectual property.

 

Studying some open source material gives a clue as to the approaches required - for example the NmraDcc section on this webpage is a start - http://www.lucadentella.it/en/2018/12/31/dcc-configurazione-decoder-con-cv/

 

BUT unless you want to get into open source programming, its not going to help a lot - so again - 

 

1 hour ago, Nigelcliffe said:

 

So, given its unique per manufacturer,  you're reduced to working through the manufacturer's manuals, slowly putting together what you think may be happening.

 

 

I think that is about the only workable approach.

[WIMorrison]

I suggest that you stick to one manufacturer of decoders - there are several very good comprehensive OEMs (e.g. ESU & Zimo) that are well documented and only use those makers decoders as you will start to understand how that OEM implements his interpretation of the 'standard'. Trying to cover all makers and all variations of decoders would be an impossible task, as has already been suggested.

 

Personally I stick with Zimo, they have an excellent range and their documentation is good covering all decoders in one fairly dense doc.

 

http://www.zimo.at/web2010/documents/MX-KleineDecoder_E.pdf

 

Good luck - if you do create a book of your findings it may be a best seller (at least within the DCC world )

 

 

 

[philiprporter]

Thanks very much indeed everyone-this is all very helpful and clearly I have a steep learning curve ahead, but this has really helped clarify things and point me in the right direction - sincere thanks!

[JJGraphics]

14 hours ago, WIMorrison said:

 

Good luck - if you do create a book of your findings it may be a best seller (at least within the DCC world )

 

 

The problem is that any book would be out of date before it was published as things change so quickly in the world of DCC.

 

John

 

 

Edited January 23, 2020 by JJGraphics

[Crosland]

17 hours ago, JimFin said:

I would agree with that thought. My understanding is that the NMRA tables indicate the required end result for a specific CV value but it is up to individual manufacturers how they achieve that result.

 

As is often the case with software, there can be many ways to achieve a specific end result, some more elegant than others, some more robust than others but to understand how a specific decoder achieves a specific end result  would mean going into the manufacturers source code and reverse engineering it since I suspect they would all decline to give you access to their intellectual property.

 

The NMRA only covers the standard required or recommended CVs, i.e. the minimum set needed to give a functional, standards compliant decoder. As Nigel says the rest really are up to the manufacturer, both end result and implementation. For a complex sound decoder these will far outnumber anything specified by the NMRA. The NMRA do not even touch upon CVs for sound decoders.

 

So the differences really are in the function of the CVs, not the way a particular end result is arrived at.

 

Any comprehensive book on CVs would be out of data before it even reached the shops.

[BromsMods]

For links to manufacturer manuals try here - https://clarahost.clara.net/www.bromsgrovemodels.co.uk/dcc_manufac_manuals.htm

[tractor_37260]

For Loksound V4 and V5 decoders a Lokprogrammer makes easy work of changing all settings and CV's especially when index CV's are used. Use in combination with the relevant Loksound user manual.

All sorts of settings can be adjusted/set : dimming/soft start/set delays in light change over/KD shuffle/sound fade/rea!locating F Key functions etc. no need to know what CV's /settings are required the Lokprog does it all for you - once you get familiar with using the screen tables, a few mouse clicks and it's job done.

 

[Nigelcliffe]

9 hours ago, tractor_37260 said:

For Loksound V4 and V5 decoders a Lokprogrammer makes easy work of changing all settings and CV's especially when index CV's are used. Use in combination with the relevant Loksound user manual.

All sorts of settings can be adjusted/set : dimming/soft start/set delays in light change over/KD shuffle/sound fade/rea!locating F Key functions etc. no need to know what CV's /settings are required the Lokprog does it all for you - once you get familiar with using the screen tables, a few mouse clicks and it's job done.

 

And the JMRI interface does the same, without having to spend £130-160 on the LokProgrammer hardware.    The JMRI interface largely follows that of the ESU software for ESU decoders. 

 

Unless you're loading sounds onto the decoder, when the device is essential,  I don't see a big benefit in buying a LokProgrammer.  

 

- Nigel