Siemens SINUMERIK 828D Function Manual page 1293

Process sequence of the gear stage change
If the new gear stage is preselected, the following sequence is implemented:
1. Changeover sequence
The two following NC/PLC interface signals are set:
DB31, ... DBX82.0-82.2 (setpoint gear stage A to C)
DB31, ... DBX82.3 (change over gear stage)
In accordance with the point at which NC/PLC IS:
DB31, ... DBX18.5 (Oscillation speed)
is set, the spindle decelerates to a standstill at the acceleration for oscillation or at the acceleration for speed
control/position control.
Oscillation can be activated at the latest when the spindle reaches a standstill:
DB31, ... DBX61.4 (Axis/Spindle stationary)
with NC/PLC IS:
DB31, ... DBX18.5 (Oscillation speed).
In principle, the new gear stage can also be engaged without oscillation
When the new gear stage is engaged, the following NC/PLC interface signals are set by the PLC program:
DB31, ... DBX16.0-16.2 (actual gear stage A to C)
DB31, ... DBX16.3 (gear is changed)
2. End of gear stage change
The gear stage change is treated as completed (spindle operation type "oscillation mode" is deselected), if the
following NC/PLC interface signal is set:
DB31, ... DBX16.3 (gear is changed)
The new actual gear stage is changed to the servo and interpolation parameter set when the motor is
stationary.
With NC/PLC interface signal:
DB31, ... DBX16.3 (gear is changed)
is used to communicate to the NC that the new gear stage is valid and the oscillation mode can be completed.
NC/PLC IS:
DB31, ... DBX82.3 (Change gear)
is reset by the NCK,
which causes the PLC program to reset NC/PLC IS:
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
S1: Spindles
16.4 Configurable gear adaptation
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