Thanks for the quick response!
I havent found anything relevant to the dual resolver tracking in the conveyortech manual It shows how to make the robot follow the motion master, but no reference to having that motion masters position dependant on the other. I've attached a moch-up of the "Theoretical Motion Master Heirarchy" I'm looking for. Note both conveyors are external and only have resolver feedback back to the robot controller. Also, I really wouldnt be switching bases per se. I need a base that is the combination of the two resolver outputs so both conveyors can be moving at the same time while picking a part thats on a motion path that is the combination of the two conveyors resolvers.
My experience is limited with Robots in general, but I would think this would be akin to have the TCP track a part on a weld positioner thats mounted on top of a rotary table. My application isn't that, but thinking its probably somewhat more common.
Just spitballing, I mocked up another scenario I'm wondering if it might work. If I attached the new conveyor resolver as connected to the robot flange, then left the Robot as tracking conveyor A, might this provide the expected result?