Mastering Absolute & Incremental Workpiece Positions in Heidenhain CNC Controls

Heidenhain cnc control uses very easy way to reference Absolute and Incremental Coordinates.
For Absolute Coordinates Axis are referenced as normal
X = X axis Absolute Position (Coordinate)
Y= Y axis Absolute Position (Coordinate)

For Incremental Coordinates “I” is prefixed the Axis which CNC machinist want to access,
IX = X axis Incremental Position or Coordinate
IY = Y axis Incremental Position or Coordinate

Absolute Workpiece Positions (Absolute Coordinate)

Absolute coordinates are position coordinates that are referenced to the datum of the coordinate system (Workpiece Zero Point).

Each position on the workpiece is clearly defined by its absolute coordinates.

Heidenhain Absolute Workpiece Positions Example

Example 1: Holes dimensioned in absolute coordinates
Hole 1            Hole 2           Hole  3
X = 10 mm  X = 30 mm  X = 50 mm
Y = 10 mm  Y = 20 mm  Y = 30 mm

Incremental Workpiece Positions (Incremental Coordinate)

Incremental coordinates are referenced to the last programmed nominal position of the tool, which serves as
the relative (imaginary) datum.

Use Prefix I

To program a position in incremental coordinates, enter the prefix “I” before the axis.

Heidenhain Incremental Workpiece Positions

Example 2: Holes dimensioned in incremental coordinates
Absolute coordinates of Hole 4
IX = 10 mm
IY = 10 mm
Incremental coordinates of Hole 5, referenced to Hole 4
IX = 20 mm
IY = 10 mm
Incremental coordinates Hole 6, referenced to Hole 5
IX = 20 mm
IY = 10 mm