Siemens SINUMERIK 840Di Function Manual page 1471

2.6.2 Calibration by entering a reference point offset
Function
If adjustment is performed by entering a reference point offset, the difference between the
actual position displayed on the HMI user interface and the real actual position in the
machine is determined and passed on to the NC as the reference point offset.
Sequence
Proceed as follows to perform an adjustment by entering the reference point offset:
1. Determine the position of the machine axis relative to the machine zero point, for
2. Establish the actual position of the machine axis displayed by the NC on the HMI user
3. Enter the reference point offset as the difference between the actual positions determined
4. Identify the absolute encoder as calibrated:
5. Initiate POWER ON reset.
6. Check the machine axis position displayed on the HMI user interface.
Reference Point Approach (R1)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
example, by:
– Measuring the position (e.g., laser interferometer)
or
– Moving the machine axis to a known position (e.g., fixed stop)
interface.
under Items 1 and 2:
MD34090 $MA_REFP_MOVE_DIST_CORR (reference point offset)
MD34210 $MA_ENC_REFP_STATE = 2
Note
The encoder adjustment does not become active until the next time the encoder is
activated (e.g., when the controller is powered up).
2.6 Referencing with absolute value encoders
Detailed Description
2-31