HEIDENHAIN TNC 406 - Manual (Page 252)

HEIDENHAIN TNC 406, TNC 416 231
12.1 MOD functions
Position Display Types
The positions indicated in the figure are:
„
Starting position A
„ Target position of the tool Z
„ Workpiece datum W
„ Scale datum M
The TNC position displays can show the following coordinates:
Select the desired display type with the horizontal arrow keys. It
immediately appears in the status field.
Unit of measurement
This MOD function determines whether the coordinates are displayed
in millimeters (metric system) or inches.
„ To select the metric system (e.g., X = 15.789 mm),
set the MOD function CHANGE MM/INCH to MM.
The value is displayed to 3 decimal places.
„ To select the inch system (e.g., X = 0.6216 inch)
set the MOD function CHANGE MM/INCH to INCH.
The value is displayed to 4 decimal places.
Function Display
Nominal position: the instantaneous value
commanded by the TNC 1 NOML.
Actual position: the position at which the tool is
presently located 2 ACTL.
Servo lag: difference between nominal and actual
positions 3 LAG
Reference position; the actual position relative to
the scale datum 4 REF
Distance remaining to the programmed position;
difference between actual and target positions 5 DIST.
Nominal position referenced to the transformed
coordinate system, such as after a datum shift NOM.W
Actual position referenced to the transformed
coordinate system, such as after a datum shift ACT.W
5 4
2 3
1
Z
A
W
M