Siemens SINUMERIK 840Di Function Manual page 1524

Detailed Description
2.1 Spindle modes
The braking start point calculation identifies when the programmed spindle position can be
approached accurately at the acceleration defined in machine data:
MD35210 $MA_GEAR_STEP_POSCTRL_ACCEL.
At the time identified by the braking start point calculation in phase 1, the spindle brakes to
standstill with the acceleration from machine data:
MD35210 $MA_GEAR_STEP_POSCTRL_ACCEL.
Phase 3
At the time identified by the braking start point calculation in phase 2, the spindle brakes to
standstill with the acceleration from machine data:
MD35210 $MA_GEAR_STEP_POSCTRL_ACCEL.
Phase 3a:
When the SPOS command is activated the proximity of the end point is such that the spindle
can no longer be accelerated up to machine data:
MD35300 $MA_SPIND_POSCTRL_VELO.
The spindle is braked to standstill with the acceleration in machine data:
MD35210 $MA_GEAR_STEP_POSCTRL_ACCEL.
Phase 4, 4a
The spindle is stationary and has reached the end point. Position control is active and holds
the spindle in the programmed position.
NC/PLC IS:
DB31, ... DBX60.6 (position reached with exact stop coarse)
and
DB31, ... DBX60.7 (position reached with exact stop fine)
are set if the distance between the spindle actual position and the programmed position
(spindle setpoint position) is less than the settings for the exact stop fine and coarse limits.
This is defined in machine data:
MD36010 $MA_STOP_LIMIT_FINE
and
MD36000 $MA_STOP_LIMIT_COARSE.
Phase 3:
At the time identified by the braking start point calculation in phase 2,
the spindle brakes to standstill with the acceleration from machine data:
MD35210 $MA_GEAR_STEP_ POSCTRL_ACCEL.
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Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Spindles (S1)