Kuka uses a relative rotation system, Fanuc an absolute one What's important is that an order in one system is the opposite in the other In other words : ==> Rz, Ry , Rx in a relative system = Rx, Ry, Rz in an absolute system.
Sorry for the late answer, I didn‘t get a message upon your comment. Yes ABC at Kuka are rotations around the ZYX axes of the tool coordinate system. My ‚toy‘ is a business gift from Fanuc and if I remember well their answer why they have put A on the X axis was that this is related to their CNC machines. So nothing to do with Kuka.
Sorry I never worked with an ABB robot so far, but at the end of the following page a lot of the conventions used by the manufactures are listed. Alternatively download and install ABB RobotStudio and just give it a try. robodk.com/blog/robot-euler-angles/
My robot controller doesn't have ROBROOT yet, but you are right that today ROBROOT is located at the robot base of the individual robot and the idea of WORLD is more to be a common coordinate system of a complete robot cell that might contain multiple robots. Nevertheless, WORLD and ROBROOT are identical until you define a non default $ROBROOT.
Good question as they are really well done. These are commercial gifts I got from Fanuc Europe who are based here in Echternach (Luxembourg). Unfortunately you cannot buy them and I think I understood that it's an exclusive Fanuc Europe gadget. I would try to contact your local Fanuc marketing office.
