Siemens SINUMERIK 808D ADVANCED Parameter Manual page 261

It describes the offset between the machine zero and the zero point of the absolute
measuring system.
Note:
In conjunction with absolute encoders, this MD is modified by the control during
calibration processes and modulo offset.
With rotary absolute encoders (on linear and rotary axes), the modification frequency
also depends on the setting of MD34220 $MA_ENC_ABS_TURNS_MODULO.
Manual input or modification of this MD via the part program should therefore be
followed by a Power ON Reset to activate the new value and prevent it from being lost.
The following applies to an NCU-LINK:
If a link axis uses an absolute encoder, every modification of MD34090
$MA_REFP_MOVE_DIST_CORR on the home NCU (servo physically available) is updated only
locally and not beyond the limits of the NCU. The modification is therefore not visible
to the link axis. Writing MD34090 $MA_REFP_MOVE_DIST_CORR through the link axis is
rejected with alarm 17070.
34092 REFP_CAM_SHIFT
mm, degrees Electronic cam offset for incremental measuring systems
-
- 1
Description:
Electronic cam offset for incremental measuring systems with equidistant zero marks.
When the reference cam signal occurs, the zero mark search does not start immediately
but is delayed until after the distance from REFP_CAM_SHIFT.
This ensures the reproducibility of the zero mark search through a defined selection
of a zero mark, even with temperature-dependent expansion of the reference cam.
Because the reference cam offset is calculated by the control in the interpolation
cycle, the actual cam offset is at least REFP_CAM_SHIFT and at most REFP_CAM_SHIFT+
(MD34040 $MA_REFP_VELO_SEARCH_MARKER*interpolation cycle)
The reference cam offset is effective in the search direction of the zero mark.
The reference cam offset is only active if existing cam MD34000
$MA_REFP_CAM_IS_ACTIVE=1.
34093 REFP_CAM_MARKER_DIST
mm, degrees Reference cam/reference mark distance
-
- 1
Description:
The value displayed corresponds to the distance between exiting the reference cam and
the occurrence of the reference mark. If the values are too small, there is a risk of
not being able to determine the reference point due to temperature reasons or varying
operating times of the cam signal. The distance travelled may serve as a clue for
setting the electronic reference cam offset.
This machine data is a display data and can therefore not be changed.
34100 REFP_SET_POS
mm, degrees Reference point for incremental system
-
- 4
Parameter Manual
Parameter Manual, 08/2015, 6FC5397-8EP40-0BA1
0.0, 0.0 0.0
0.0, 0.0 -
0., 0., 0., 0. -45000000
3.4 Axis-specific machine data
A03, A11 G1, R1
DOUBLE Reset
- 2/2
A03, A11 R1
DOUBLE PowerOn
- 2/2
A03, A11 G1, S3, G2, R1, S1
DOUBLE Reset
45000000 2/2
Machine data
261