14 I Operating Instructions
I – 1 Fundamentals of Positioning
Example: Coordinates of hole 1:
X =10 mm
Y = 5 mm
Z = 0 mm (hole depth: Z = – 5 mm)
The datum of the Cartesian coordinate system is located 10 mm from 
hole 1 in the X axis and 5 mm from it in the Y axis. See Fig. I.4.
The KT Edge Finder from HEIDENHAIN, together with the 
POSITIP 880's edge finding functions, facilitates finding and setting 
datums.
Nominal Position, Actual Position and Distance-
To-Go
The position that the tool is to move to is called the nominal position 
while the position of the tool at any given moment is called the actual 
position. The distance from the nominal position to the actual position 
is called the distance-to-go. See Fig. I.5.
Sign for distance-to-go
The distance-to go has a positive sign if the axis direction from the 
actual towards the nominal position is negative.
The distance-to-go has a negative sign if the axis direction from the 
actual towards the nominal position is positive.
Fig. I.4 Hole 1
 defines the coordinatesystem
Fig. I.5 Nominal position S, actual position I and 
distance-to-go R