Siemens SINUMERIK 840D Function Manual page 791

Spindle in axis mode
If the spindle is in axis mode, the parameter set index "0" is selected in the servo (note
MD35590 $MA_PARAMSET_CHANGE_ENABLE!).
The gear stage change behavior depends on the setting in the machine data:
MD35014 $MA_GEAR_STEP_USED_IN_AXISMODE (gear stage for axis mode in M70)
If there is no gear stage configured for axis mode (MD35014 = 0), no implicit gear stage change
takes place in M70 (default setting!). The last gear stage is saved internally and is reactivated
with the associated parameter set during the next spindle programming.
If, however, a gear stage is configured for axis mode (MD35014 = 1 ... 5), a gear stage change
to gears 1 ... 5 takes place during the execution of M70. When changing from axis mode to
spindle mode, the gear stage loaded with M70 remains activated. The gear stage which is
activated in spindle mode prior to M70 is not automatically loaded again.
See also "Configurable gear step in M70 (Page 805)."
Load gearbox transmission ratio
It is possible to configure positive or negative load gearbox factors for each gear stage and in
axis mode.
The setting is undertaken separately for numerator and denominator via the machine data:
MD31050 $MA_DRIVE_AX_RATIO_DENOM[n] (load gearbox denominator)
MD31060 $MA_DRIVE_AX_RATIO_DENOM[n] (load gearbox numerator)
The setting range is the same size for positive and negative load gearbox factors.
It is not possible to enter the value "0".
Note
If an indirect encoder is configured, and the load gearbox transmission ratio changes, then the
reference is lost and the NC/PLC interface signal:
DB31, ... DBX60.4/60.5 (referenced/synchronized 1 or 2)
is reset for the relevant measuring system.
Further information
For further information about control and servo parameter set, please refer to:
● G2: Velocities, setpoint / actual value systems, closed-loop control (Page 31)
● Programming Manual Advanced; Programmable servo parameter set
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
S1: Spindles
18.4 Configurable gear adaptations
791