Siemens SINUMERIK 808D Function Manual page 161

Phase 5: The position control remains active and stops the spindle in the programmed position. The IS "Position reached
with exact stop fine" (DB390x.DBX0000.7) and "... coarse" (DB390x.DBX0000.6) 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 (respectively defined in MD36010 STOP_LIMIT_FINE and MD36000 STOP_LIMIT_COARSE).
Positioning from standstill, spindle not synchronized
The spindle is not synchronized after the control has been activated. The first movement of the spindle must be positioning
(SPOS=...).
Positioning with stopped, non-synchronized spindle:
Sequence
Phase 1: Programming SPOS accelerates the spindle with the acceleration in MD35210 GEAR_STEP_ POSCTRL_ACCEL
(acceleration in position control mode) until the maximum speed entered in MD35300 SPIND_POSCTRL_VELO (position
control activation speed) is reached.
The direction of rotation is defined by MD35350 SPIND_POSITIONING_ DIR (direction of rotation during positioning from
standstill), if no input results from SPOS programming (ACN, ACP, IC). The spindle is synchronized with the next zero mark
of the position actual value encoder.
Phase 2: When the spindle is synchronized, the position control is activated. The spindle rotates at the maximum speed
stored in MD35300 SPIND_POSCTRL_VELO until the braking start point calculation identifies the point at which the
programmed spindle position can be approached accurately with the defined acceleration.
Phase 3: At the brake application point, the spindle is braked down to standstill with the acceleration set in
MD35210 GEAR_STEP_ POSCTRL_ACCEL (acceleration in position control mode).
Phase 4: The spindle has reached the target point and is stationary. The position control is active and stops the spindle in
the programmed position. The IS "Position reached with exact stop fine" (DB390x.DBX0000.7) and "... coarse"
(DB390x.DBX0000.6) 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 (MD36010 STOP_LIMIT_FINE and
MD36000 STOP_LIMIT_COARSE).
Positioning from standstill, spindle is synchronized
The spindle has already been turned by one spindle revolution with M3 and M4 and was then brought to a standstill with M5.
Positioning with stationary, synchronized spindle:
Function Manual
161
01/2017