Siemens SINUMERIK 840D sl Function Manual page 1568

Detailed description
2.4 Referencing with incremental measurement systems
Phase 3: Sequence
The machine axis moves at the assigned reference point positioning velocity:
MD34070 $MA_REFP_VELO_POS (reference point positioning velocity)
from the encoder zero mark detected in Phase 2 to the reference point.
The path s
reference point offset:
MD34080 $MA_REFP_MOVE_DIST (reference point distance)
MD34090 $MA_REFP_MOVE_DIST_CORR (reference point offset)
MD34020 $MA_ REFP_VELO_SEARCH_CAM
(Reference point approach velocity)
MD34070 $MA_REFP_VELO_POS
(Reference point positioning velocity)
MD34040 $MA_REFP_VELO_SEARCH_MARKER
(Reference point creep velocity)
Figure 2-9
When the reference point is reached the machine axis is stopped and the actual value
system of the machine axis is synchronized with the reference point value specified by the
PLC user program.
MD34100 $MA_ REFP_SET_POS [ n] (Reference point value)
The reference point value is specified by the PLC user program via:
DB31, ... DBX2.4 / .5 / .6 / .7 (reference point value 1 / 2 / 3 / 4)
The reference point value, which was selected by the PLC user program at the time of the
arrival of the reference cam in Phase 1 (DB31, ... DBX12.7 = 1), is taken over by the NC.
The machine axis is now referenced. As identification, the NC sets the appropriate interface
signal depending on the active measuring system:
DB31, ... DBX60.4 / .5 (Referenced/Synchronized 1 / 2) = 1
22
to be covered is calculated from the sum of the reference point distance plus
ref
Reference point position
Velocity
MD34100 $MA_REFP_SET_POS [0/1/2 OR 3]
MD34080 $MA_REFP_MOV_DIST +
MD34090 $MA_REFP_MOVE_DIST_CORR
Zero Mark
Basic logic functions: Reference Point Approach (R1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Distance
of reference
point cam
DELAY
of reference
point approach