ACU-RITE 300S READOUTS - Manual (Page 16)

2 I
I - 1 F
undamentals of P
o
sitioning
I - 1 Fundamentals of Positioning
Datums
The workpiece drawing identifies a certain point on the workpiece
(example: “a corner”) as the absolute datum, and perhaps one, or
more other points as relative datums.
The datum setting procedure establishes these points as the origin of
the absolute, or relative coordinate systems. The workpiece, which is
aligned with the machine axes, is moved to a certain position relative
to the tool. The display is set either to zero, or to another appropriate
value (e.g., to compensate for tool radius).
Actual Position, Nominal Position, and
Distance-To-Go
The position of the tool at any given moment is called the ACTUAL
POSITION I, while the position that the tool is to move to is called the
NOMINAL POSITION S. The distance from the nominal position to
the actual position is called the DISTANCE-TO-GO R.