Location Variables Location Variables Locations can be specified in two ways in eV+: transformations and precision points. A transformation is a set of six components that uniquely identifies a location in Cartesian space and the orientation of the motion device end-of-arm tooling at that location. A transformation can also represent the location of an arbitrary local reference frame. A precision point includes an element for each joint in the motion device. Rotational joint values are measured in degrees; translational joint values are measured in millimeters.
These values are absolute with respect to the motion device's home sensors and cannot be made relative to other locations or coordinate frames. Coordinate Systems The following figure shows the world coordinate system for an Omron Adept SCARA robot and an Omron Adept Cartesian robot. Ultimately, all transformations are based on a world coordinate system. The eV+ language contains several instructions for creating local reference frames, building relative transformations, and changing the origin of the base (world) coordinate frame. Therefore, an individual transformation may be relative to another transformation, a local reference frame, or an altered base reference frame.
Different robots and motion devices designates different locations as the origin of the world coordinate system. See the user's guide for Omron Adept robots to determine the origin and orientation of the world coordinate frame. eV+Language User's Guide, v2.x, 18318-000 Rev A Page 102