Siemens SINUMERIK 808D Function Manual page 153

Different motion sequences during referencing:
Referencing type
With reference cam (MD34000
REFP_CAM_IS_ACTIVE = 1)
Without reference cam
(MD34000
REFP_CAM_IS_ACTIVE = 0)
V - reference point approach velocity (MD34020 REFP_VELO_SEARCH_CAM)
C
V - reference point creep velocity (MD34040 REFP_VELO_SEARCH_MARKER)
M
V - reference point positioning velocity (MD34070 REFP_VELO_POS)
P
R - reference point offset (MD34080 REFP_MOVE_DIST + MD34090 REFP_MOVE_DIST_CORR)
V
R - reference point coordinate (MD34100 REFP_SET_POS)
K
What is the minimum length of a reference cam?
Example of case: Synchronizing pulse before cam, reference coordinate before synchronizing pulse = synchronizing pulse
search with falling cam edge.
The reference cam must be long enough, so that when the cam is approached with the reference point approach velocity,
the braking operation ends at the cam (the axis comes to a standstill at the cam), and the cam is exited in the opposite
direction with the reference point creep velocity (exit with constant velocity).
To calculate the minimum length of the cam, the larger of the two velocities must be inserted into the formula:
If the machine axis does not come to a halt at the reference cam (interface signal "Reference point approach delay"
(DB380x.DBX1000.7) is reset), alarm 20001 is output. Alarm 20001 can occur if the reference cam is too short and the
machine axis travels over it when decelerating in phase 1.
If the reference cam extends to the end of travel of the axis, an inadmissible starting point for referencing (after the cam) can
be excluded.
Function Manual
01/2017
Synchronizing pulse
(zero mark, BERO)
Synchronizing pulse before cam,
reference coordinate before synchro-
nizing pulse = without reversal:
(MD34050
REFP_SEARCH_MARKER_REVERS
E = 0)
Synchronizing pulse on cam, refer-
ence coordinate after synchronizing
pulse on cam = with reversal:
(MD34050
REFP_SEARCH_MARKER_REVERS
E = 1)
Reference coordinate after synchro-
nizing pulse
Motion sequence
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