Commissioning: Axis-Specific Machine Data; Supplementary Conditions - Siemens SINUMERIK 840D sl Function Manual

K3: Compensations
5.3 Backlash compensation
Preconditions
The following preconditions must be satisfied for an axis to be compensated:
● Direct and indirect measuring system, mechanically coupled:
– MD30200 $MA_NUM_ENCS = 2
– MD31040 $MA_ENC_IS_DIRECT[ 0 ] = 0 or 1
– MD31040 $MA_ENC_IS_DIRECT[ 1 ] = 1 or 0
● Measuring system calibration has been released:
MD34102 $MA_REFP_SYNC_ENCS = 1
● Both measuring systems are referenced:
– DB31, ... DBX60.4 (referenced/synchronized 1 / 2) = 1
– DB31, ... DBX60.5 (referenced/synchronized 1 / 2) = 1
5.3.3.1

Commissioning: Axis-specific machine data

Delay time
The delay time, during which the closed-loop control smoothly transitions from the indirect to
the direct measuring system, is entered in the machine data.
MD32960 $MA_POSCTRL_DUAL_FEEDBACK_TIME = <delay time>
If the delay time is zero, then the function is inactive, and only the active measuring system
(DB31, ... .DBX1.5 / .6 (position measuring system 1 / 2) ) is active for the position control.
Note
After activating the "Dual position feedback" function, all of the existing measuring system
compensations and monitoring functions remain unchanged and active; this means that they
may have to be deactivated by the user (e.g. backlash compensation values deleted).
5.3.3.2

Supplementary conditions

Referencing and flying measurement
Also when the "Dual position feedback" function is active, the "Referencing" and "Measuring"
functions refer to the active measuring system (DB31, ... .DBX1.5 / .6 (position measuring
system 1 / 2) ).
References
● Function Manual Basic functions, Chapter "R1 Referencing"
● Function Manual Extended Functions, Chapter "M5 measuring"
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Function Manual, 10/2015, 6FC5397-1BP40-5BA3
Extended Functions