Mk.2 interface commands

On the lower case x|y|z commands, what is ? Is it the same as the address in the ‘A’ command?

Traditionally, all the hex commands were w commands, so a single command thread was available. From what I understand from the documentation, w,x,y,z are now available, giving 4 threads to the command sequence. the prefix is used to determine which command thread is being replied to.
Personally, I don’t see much use for this, but in a complex system, this might be valuable.

What I’m discussing is the set of lower case commands that seem to be intended for communicating with Quattros other than the master. I wondered where “destination address” came from.

The normal X|Y|Z commands are really useful, for instance if using the 0x37 command to set charge current and voltage, the two replies would be identical without the X|Y|Z.
I also note that W commands are mode 1 by default, but X|Y|Z commands appear to be mode 2.