RS-232 Programming Russound CAV6.6 - Target Path?

["Phrogz" <gavin@xxxxxxxxxxxx>]

Hi there, I'm about to be the owner of a CAV66 that I will be
controlling from my computer. I'm writing a library to control it (in
Ruby, for those who care), but the RNET RS-232 protocol PDF that
Russound offers on their website seems to be a little short on details.

Specifically, what are bytes 9-12 as listed in the samples at the end
of the PDF, and as detailed in a couple byte-by-byte break downs of
example packets?

For these bytes, one of the breakdowns says:
Value   Field                                    Description
02       Target Path, Num Levels
02       Target Path, Level 1               Root Menu
00       Target Path, Level 2               Run Menu
00       Source Path, Num Levels       No Source Path is used

I assume that the "Num Levels" byte indicates how many following bytes
will be used, but I can't see anything in the spec that explains what
the various "levels" are, or when they should be used. "Root Menu"?
"Run Menu"? Is this a tree hierarchy of commands that sets a state for
the processing, or something?

I've written to Russound Tech Support, but so far they've just said
"Our documentation is complete; hex programming is hard. Most people
use the examples at the end of the document." Unfortunately, various
examples use different values for these bytes, and I'd like to know
what they mean.

Does anyone have a deeper insight on this spec?

If not, does anyone know of any open-source code others have written
(in any language, really) for working with the Russound RNET packet
protocol?