Configurable Gear Step In M70 - Siemens SINUMERIK 840D Function Manual

The determination of the transition condition has an effect firstly on the gear stage change time
and secondly on the accuracy of the approach to the preset gear stage change position.
Block change
The block change is stopped and the machining blocks are not started until the gear stage has
been changed by the PLC (DB31, ... DBX16.3).
End of gear stage change
Once the gear stage change has been completed, the spindle returns to open-loop control
mode and will automatically change to the closed-loop control mode defined by SPCON
or SPCOF.
All gear-specific limit values (min./max. speed of gear stage, etc.) correspond to the check-
back values of the actual gear stage.
Supplementary conditions
● The spindle must have at least one measuring system.
● Position-controlled operation must be possible and must have been activated.
● Generally, it must be possible to execute SPOS from the part program, from a synchronized
action or via FC18: "Start spindle positioning" without errors.
Unless all requirements can be met, the function described cannot be used successfully.
Activation
The function of gear stage change at fixed position
is activated by the configuration:
MD35010 $MA_GEAR_STEP_CHANGE_ENABLE = 2
18.4.9

Configurable gear step in M70

Technical background
In some machines the spindle needs to be in a particular gear stage during axis mode.
Possible reasons:
● Only one optimization (K
servo parameter set for axis mode (index 0). The machine data for this parameter set should
not be rewritten.
● There is only one mechanical transmission ratio which, unlike the others, possesses little or
no backlash compensation. The spindle can only follow a path motion or transformations
(e.g. TRANSMIT) together with other axes in this gear stage.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
, feedforward control, filter) to suit a gear stage can be found in the
V
S1: Spindles
18.4 Configurable gear adaptations
805