SYSTEM FOR DETERMINING A STATE OF A TOOL POSITIONING MACHINE

System for providing state information for at least a part of a tool positioning machine (5) embodied as manipulating machine or as coordinate measuring machine. The system comprises the tool positioning machine (5) defining a machine coordinate system and having a base (31) and a machine structure. The structure comprises a tool head and structural components (32-34) for linking the tool head to the base, at least one drive mechanism for providing movability of the machine structure relative to the base (31), a position determining system for deriving at least one coordinate of the machine structure in the machine coordinate system and a controlling unit adapted for controlling movement of the machine structure. The system comprises a calibration setup comprising at least two calibration components which are provided by a touch tool (35) and a calibration artefact (11,11'). One of the at least two calibration components is mounted on the machine structure and defines a moveable reference point, another one of the at least two calibration components is arranged with defined spatial relation to the base (31) and provides a nominal calibration position (13). The calibration artefact (11,11') comprises at least two touching regions which are aligned transverse to one another and the calibration artefact (11,11') and the touch tool (35) are arranged so and moveable by the machine structure relative to each other so that simultaneous contact of the touch tool (35) with the at least two touching regions is providable.