Automatic Calibration With Probe - Siemens SINUMERIK 840D Function Manual

7. Operate the travel key used for referencing in step 2.
The machine axis does not move when the traversing key is actuated!
The NC calculates the reference point offset from the entered reference point value and that
given by the absolute encoder. The result is entered into the machine data:
MD34090 $MA_REFP_MOVE_DIST_CORR (reference point offset)
The status of the absolute encoder is set to "Encoder is adjusted":
MD34210 $MA_ ENC_REFP_STATE = 2
The actual value system of the machine axis is synchronized.
The machine axis is now referenced. As identification, the NC sets the appropriate interface
signal based on which measuring system is currently active:
DB31, ... DBB60.4 / 60.5 (referenced/synchronized 1 / 2) = 1
8. Initiate Power On reset.
Note
Activate reference point offset permanently
The entered reference point offset (MD34090) will only be permanently active after Power
On reset.
If the machine axis is moved after the absolute encoder adjustment without an interim
Power On reset, the reference point offset entered in the machine data can be overwritten,
for example, within internal overrun corrections.
Checking the actual position
Following adjustment of the absolute encoder, we recommend that you verify the actual
position of the machine axis the next time you power up the controller (Power On).
10.9.4

Automatic calibration with probe

Function
In automatic adjustment with a probe, a known position in the machine is approached with the
machine axis from a part program. The position value is stored in the NC as a reference point
value. The position is reached when the probe switches, and the NC then calculates the
reference point offset from the difference between the encoder value and reference point value.
Note
Part program for automatic adjustment
The part program for automatic adjustment using a probe must be created by the machine
manufacturer / user for the specific requirements of the machine.
Freedom from collision
Because actual-value-related monitoring is not active for the machine axes being referenced,
the machine operator must take special care to ensure that collisions do not occur in the
machine while the machine axes are being moved!
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
10.9 Referencing with absolute encoders
R1: Referencing
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