In the Setup Manager you can define the Machining Coordinate System (MACSYS). This defines the orientation of the part (to be machined) on the machining center. The Setup is defined parallel to a pre-defined UCS.

If the model contains more than one UCS, you can redefine the Setup
UCS by clicking on the Setup name, then clicking the UCS button
. You can then select the UCS from the drop-down list, or
select it manually on the screen.
Note: Once the document contains a toolpath, you cannot change the NC Setup Report.