gobbleygook DCC

[rrinker]

This is where knowing something about bits and bytes would come in handy. The packet specification in the NMRA standards allows for 7 bits for the address field. 7 bits allows for any number from 0-127. Lenz's original pre-DCC system could only addres 99 locos. CVP just imitated that. Digitrax and NCE built theirs to use the entire 7 bits.
Then came the extended packet format and 'long' addresses using CV17 and 18. Rather than fix this discontinuity and possibly tick off one or more manufacturers, the NMRA just skirted the issue and left it open to wide interpretation. Most decoders don't care - the difference is in the command station.

Digitrax: 1-127 is short, 128+ is long, no exceptions
Lenz: 1-99 is short, 100+ is long, no exceptions
CVP - same as Lenz
NCE - 1-127 is short, 128+ is long but ALSO 1-127 can be long.

This can lead to issues when moving a loco between different systems - for example if I have loco 102 on a Digitrax system I cannot run it without reprogramming on CVP or Lenz. If I have 102 configured on a CVP or Lenz system, it won't run on DIgitrax. On NCE, I can have loco 50 and 050, one short, one long - and they are two different locos!

--Randy