Siemens SINUMERIK 840D sl, Function Manual

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Detailed description
2.7 Referencing by means of actual value adjustment
Basic logic functions: Reference Point Approach (R1)
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Function Manual, 11/2006, 6FC5397-0BP10-2BA0
2.7.2 Actual value adjustment to the referenced measurement system
Function
If a machine axis has several measuring systems and one of them is referenced, the
remaining measuring systems can be referenced by actual value adjustment to the
measuring system already referenced.
Advantage
Referencing does not take as long because the path to be traversed only has to be
sufficiently along to allow elimination of the backlash in both measuring systems.
If the distance to the traversing range limits is large enough, referencing can be started at
any point along the traversing range of the machine axis in any direction because no zero
mark, reference point cam, etc., is required.
Parameterization
The following machine data must be parameterized for actual value adjustment to a
referenced measuring system:
•
Homing mode: Actual value adjustment to a referenced measuring system
MD34200 $MA_ENC_REFP_MODE[
measuring system] = 6
•
Traverse path for backlash recovery:
MD34080 $MA_REFP_MOVE_DIST[
measuring system] (reference point distance)
Note
Reference point distance greater than zero
To ensure reliable backlash recovery, the assigned value for the reference point distance
must be greater than the maximum backlash of both measuring systems.
Reference point distance equal to zero
The reference point distance can also equal zero. In this case, actual value adjustment is
performed without a traversing movement as soon as reference point approach starts. In
this case, the active backlash should be less than half the increment of the measuring
system whose actual value is taken.