Siemens SINUMERIK 840D sl Function Manual page 1632

Detailed Description
2.1 Spindle modes
Phase 3
Spindle speed > Position-control activation speed
When the position-control activation speed stored in machine data:
MD35300 $MA_SPIND_POSCTRL_VELO
is reached:
• Position control is activated (if not already active)
• The distancetogo (to end point) is calculated
• Acceleration in machine data:
Spindle speed < Position-control activation speed
To reach the end point, the spindle is accelerated up to the speed defined in machine data:
MD35300 $MA_SPIND_POSCTRL_VELO (position-control activation speed).
This is not exceeded.
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.
Phase 4
Spindle speed > Position-control activation speed
The spindle brakes from the calculated "braking point" with machine data:
MD35210 $MA_GEAR_STEP_POSCTRL_ACCEL
to the end point.
Spindle speed < Position-control activation speed
At the point, which is determined by the braking start point calculation in Phase 3,
the spindle decelerates to stillstand with the acceleration given in the following machine data:
MD35210 $MA_GEAR_STEP_POSCTRL_ACCEL
.
Phase 4a:
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 decelerated to stillstand with the acceleration given in the following machine
data:
MD35210 $MA_GEAR_STEP_POSCTRL_ACCEL
.
22
MD35210 $MA_GEAR_STEP_POSCTRL_ACCEL (Acceleration in position control mode)
is activated (or this level of acceleration is maintained)
Basic logic functions: Spindles (S1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0