This is an interesting thread and illustrates the vast flexibility of DCC.
I would like to relate my experience with CV29 which is different from above. I have a SPROG 2 and a DIgitrax system and I have programmed CV29 on the Digitrax programming track, the Digitraz on the main, and using the SPROG and I have NEVER had the experience that changing CV29 reset any other CV on the loco.
The brochures that come with NCE decoders give a list of values for CV29. These are standard for all decoders, or should be. If not, the decoder is not fully DCC compliant.
Changing the value of CV29, does change the direction, I usually set CV29 to decimal 34 or 35. These are both 28/128 speed steps and NO analog DC. 34 is normal direction is forward based on the wiring and 35 reverses the normal direction.
I keep a 3x5 card with a list of how I set the motor CVs on a loco, and note the value of 29. With JMRI you can just print a list of the CVs also.
My experience with Digitrax and more than one loco running during an OP session is that consisted locos do not respond as quickly as the main one. With Digitrax you define the "lead" loco and then add locos to make the consist. I have noticed that the second units seem to hesitate slightly in their response when consisted. However, this may be an illusion to me because it is not a lot of time. And it may be different on other systems. I generally just set the same address on both locos when I plan to run a consist semi-permanently. Response is the same on both. I do use consists some when a set is going to be together for only one or two op sessions.
A note on NCE consists learned at the local club. If you consist locos with an NCE system. They only work with that system. They will not run if take them to another layout. You have to de-consist and re-consist on the new layout. the local club has had members show up with consists and it took a while to figure out why they would not run.
I understand that the SPROG 2 which I have will do fine programmiing all CVS including all Sound and that is my experience. I have been told however that it is not capable of downloading and installing new sound files. For that you need a QSI programmer for QSI and PR3 for Digitrax and I think Soundtraxx has their own device.
