On November 15, 2007 at 14:20, tgrugett said...
Are the two commands required for each function?
Yes. (Though I think it's clearer to describe as "two signals for each command").
Are they
two different commands for assignable control?
I don't know what you mean, but I think the answer is no.
Is one
a press and the other a release?
No.
It uses two IR signals to communicate the one command. I don't know why Pioneer chose to design it that way.
You could use such a design to get support for more than 256 different commands in each device. One or more of the single part signals are reserved for use only as the prefix of two part commands, each of which could introduce up to 256 two part commands.
But, so far as I know, Pioneer never actually has more than 256 commands per device, so they should have been able to pack the whole command set into single part commands. They just chose not to.