Siemens SINUMERIK 840D sl Function Manual page 261

Second measuring system
If an axis has a second measuring system, the compensation value must also be determined
for this and entered in the machine data:
MD32450 $MA_BACKLASH[ <measuring system 2> ]
When the measuring system is switched over, the associated compensation value is
automatically used.
Evaluation factor dependent on the parameter set
For a mechanical backlash dependent on the parameter set, the parameter set-specific factor
is entered into the machine data, which is then applied to the compensation value of the
backlash (MD32450 $MA_BACKLASH).
MD32452 $MA_BACKLASH_FACTOR[ <parameter set 1 ... n> ] = <factor>
Effective compensation value
The effective compensation value K
K = ( MD32450 $MA_BACKLASH[ <active measuring system> ] ) * ( MD32452
P
$MA_BACKLASH_FACTOR[ <parameter set> ]
Backlash compensation mode
The machine data is used to set as to whether, after the control powers up, the last effective
backlash compensation value is restored.
MD32454 $MA_BACKLASH_MODE = <value>
<Value> Meaning
Preconditions
The measuring system active after the control powers up must be adjusted and synchronized:
● MD34210 $MA_ENC_REFP_STATE[<active measuring system>] == 2
● DB31, ... .DBX60.4 - 5 == 1 (measuring system 1 / 2: Referenced, synchronized)
References
Function Manual Basic Functions; Chapter "R1: Referencing" >
Extended Functions
Function Manual, 10/2015, 6FC5397-1BP40-5BA3
1 The backlash compensation value is restored at power on
0 The backlash compensation value is not restored at power on
of a parameter set is calculated as follows:
P
K3: Compensations
5.3 Backlash compensation
261