Siemens SINUMERIK 840D Function Manual page 785

NC stop during gear stage change
The spindle cannot be stopped with NC/PLC IS:
DB21, ... DBX7.4 (NC stop)
if:
● The spindle is not yet in oscillation mode for the gear stage change.
● NC/PLC IS:
DB31, ... DBX16.3 (gear changed)
is not set.
Note
Options for aborting:
DB31, ... DBX2.2 (delete distance-to-go / spindle reset)
or
DB31, ... DBX16.3 (gear changed)
with corresponding acknowledgment from actual gear stage:
DB31, ... DBX16.0-16.2 (actual gear stage).
Spindle response after a gear stage change
How the spindle behaves once the gear stage has been changed depends on the following
initial conditions:
● If the spindle was in the stop state before the gear stage change (M5, FC18: "Stop rotate
spindle"), in positioning or axis mode, M5 (spindle stop) is active after completion of the gear
stage change.
● If a direction of rotation
(M3, M4, FC18: "Start spindle rotation"), then the last speed and direction of rotation will
become active again after the gear stage change. In the new gear stage, the spindle
accelerates to the last spindle speed programmed (S...).
● If position control was active before the gear stage change (SPCON), then it is reactivated
after the gear stage change.
The next block in the part program can be executed.
Axes and spindles
Function Manual, 06/2019, A5E47437747B AA
S1: Spindles
18.4 Configurable gear adaptations
785