Siemens SINUMERIK 840D Function Manual page 311

4. Measure the actual position of the machine axes referred to the machine zero point.
5. Calculate the absolute offset and enter in MD34090.
The absolute offset is calculated with respect to the machine coordinate system and
depending on the orientation of the measuring system as:
Reference point deviation
After determining the absolute offset and the entry in MD34090, the reference point traversing
for the machine axis must be carried out once more.
Referencing methods
Referencing with distance-coded reference marks can be performed in one of two ways:
● Evaluation of two consecutive reference marks:
MD34200 $MA_ENC_REFP_MODE = 3
Advantage:
– Short travel path
● Evaluation of four consecutive reference marks:
MD34200 $MA_ENC_REFP_MODE = 8
Advantage:
– Plausibility check by NC is possible
– Increase in reliability of referencing result
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
Orientation of the measuring system
Equidirectional
Opposite direction
WARNING
10.6 Referencing with distance-coded reference marks
Absolute offset
(Measured position) + (displayed actual position)
(Measured position) - (displayed actual position)
R1: Referencing
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