This document specifies an OPC UA Information Model which provides subtypes of BaseDataVariableType with an additional Variable, to be used in different scenarios, which need to show a relationship to a value which should act as a reference value.

This document also specifies an OPC UA Information Model, using created subtypes of BaseDataVariableType, for the representation of relative spatial locations of objects. The Relative Spatial Location (RSL) concept provides add-ins, which enable to enhance objects with location information and bring them in relationship.

For the use of the RSL concept a discrete subtype of BaseDataVariableType is defined to describe a location with position in cartesian coordinates and orientation in Euler angles inclusive a unique mathematic definition. The usage of this type is based on transformation of coordinate systems by frames, consisting of a position and orientation, which is typically used in robotics or vision systems to describe and calculate the location of an object or position.