I don't understand how the TCS WOW programming works?

[gdelmoro]

Based on the WOW guided programmer

There are 4 CV's that are used to program sounds, volume motor control and others. These SAME CV's are used no matter if you are programming a specific sound volume or start voltage. It just doesn't make sense to me. If I program CV 201 to 1 for one function and then re-program it to 43 for a different function doesn't it wipe out the 1 I originally entered and negate that program?

[tstage]

Gary,

It's probably like how CV49 & CV50 work.  CV49 is known as a primary index and CV50 is known as a secondary index.  You have to change both primary AND secondary CVs to a particular value in order to access a particular "bit" of another CV - e.g. for changing lighting or sound effects.  Which bit (there are 8 bits to a single CV) is determined by what values are given to CV49 & CV50.

The changes to the primary and secondary indexes are temporary then revert back to their default after you make the value change to a 3rd (and sometimes 4th) CV.  Does that sorta make sense?

Tom

[gdelmoro]

I think so.

In this case CV 201 is the primary.  They have several primary values that control several functions. after you enter the primary you can program that option by entering a value in CV 202, 203 & 204.

Is that correct?

[rrinker]

Yes, that's how the indexed CVs work. TCS sort of avoids the use of calling them "indexed CVs" by logically breaking the index part into the various modes - light mode, sound mode, etc. rather than the somewhat haphazard distribution of CVs sometimes seen in other decoders - some of the others seem like the developers were like "oh, we need another CV" and just used the next available number, or didn't leave enough space so that when an update came out that offered an additional sound channel along with another independent volume control, the CV for that couldn't go next to all the other volume controls and got stuck somewhere else. 

 The main reason indexed CVs exist is that most systems can't address CV numbers higher than 255. ANd wiuth all the new sound features plus 29 functions, there just weren;t enough CVs to set all that stuff. The latest NMRA spec does address CVs up to 1024, and specifies what ranges are used for what, with large chunks left as "manufacturer defined" which menas little hope that eventually all of the various decoders will be programmed somewhat similarly. The NMRA standard does specify that CVs 31 and 32 should be used for the index, giving a total of 64k pages (each page having 256 CVs), of which 4k of them are reserved by the NMRA. That's a LOT of CVs and should be enough no matter what anyone comes up with in the future - 16 MB of configuration memory. 

                       --Randy