Datum Correction - HEIDENHAIN TNC 415 Technical Manual

14 Datum correction

The PLC datum correction function is used to shift the zero or datum point with the PLC program.
Each axis (X, Y, Z, 4, 5) is assigned a double word (D528 to D544) for the correction value. The
datum correction is activated by Marker M2716 during a strobe. The correction is computed in the
actual value display; the display then relates to the shifted coordinate system.
Example:
Actual position display for X axis without correction = 50
Correction in D528 = +20
Strobe marker M2716 set, i.e. correction is active
New actual position display X= +70
The corrections can be transferred to double words, D528 to D544, from different memory areas:
- Enter values in MP4210.0 to MP4210.47 and they will also be in D768 to D956; now copy values
via PLC program into D528 to D544.
- Define corrections in the NC program in function FN19 and they will also be in D280 or D284 (see
description of FN19); now copy values via PLC program into D528 to D544.
A description of the machine geometry via machine parameters MP7510 and following (e.g. cylinder
surface) must have the same reference position as any datum shift.
Address Function
D528 Datum correction for X axis
D532 Datum correction for Y axis
D536 Datum correction for Z axis
D540 Datum correction for IV axis
D544 Datum correction for V axis
Marker Function
M2716 Strobe marker for datum correction
01.98 TNC 407/TNC 415/TNC 425 14 Datum correction 4-221