Siemens SINUMERIK 840D Function Manual page 303

Initial situation:
The machine axis is positioned on the reference cam.
Zero mark search direction:
The direction of the zero mark search results from the settings in the machine data:
● MD34010 $MA_REFP_CAM_DIR_IS_MINUS (reference point approach in minus direction)
● MD34050 $MA_REFP_SEARCH_MARKER_REVERSE (direction reversal on reference
cam)
Phase 2: Sequence
The synchronization in Phase 2 can be performed via the falling or rising edge of the reference
cam. The parameterization is performed via:
MD34050 $MA_REFP_SEARCH_MARKER_REVERSE[<axis>] = <value>
Value
0
1
Note
If the actual velocity of the machine axis at approach of the reference cam has not yet reached
the target velocity of Phase 2 within the parameterized tolerance limits, Phase 1 will be
restarted. This will be the case, for example, if the machine axis is positioned on the reference
cam when reference point approach is started.
MD35150 $MA_SPIND_DES_VELO_TOL (spindle speed tolerance)
Case 1: Synchronization with falling reference cam edge
During synchronization with falling reference cam edge, the machine axis accelerates to the
parameterized reference point creep velocity opposite to the parameterized reference point
approach direction (traversing direction of Phase 1)
After leaving the reference cam, the machine axis waits for the next encoder zero mark:
DB31, ... DBX12.7 == 0
As soon as the encoder zero mark is detected, Phase 2 comes to an end. The machine axis
continues at constant velocity and reference point approach is continued with Phase 3.
● MD34040 $MA_REFP_VELO_SEARCH_MARKER (reference point creep velocity)
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
Meaning
Synchronization with falling reference cam edge
Synchronization with rising reference cam edge
10.5 Referencing with incremental measurement systems
R1: Referencing
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