Velocity Reduction According To Overload Factor - Siemens SINUMERIK 802D sl Function Manual

Velocity = 0 in continuouspath mode
Regardless of the implicit exact stop response, the path motion is braked down to zero
velocity at the end of the block in cases where:
● The time taken to position a spindle programmed with SPOS is longer than the travel time
● A synchronization process needs to be carried out (see Section "General").
Auxiliary function output during traversal
If the traversal time is not sufficient due to the programmed path length and velocity of the
block with auxiliary function output, the path velocity for the block is reduced such that the
acknowledgment of the auxiliary function can arrive with a PLC cycle time.
If the acknowledgment is not received within one PLC cycle time, the following prepared
block cannot be processed and the axes are braked to rest with setpoint = 0 (without
considering the acceleration limits).
If the acknowledgment is not received by the end of the block in long blocks in which the
velocity has not needed to be reduced on account of the PLC acknowledgment time, the
velocity is maintained until the end of the block and then reduced as described above.
If the acknowledgment arrives while the axis is decelerating, the axis is not accelerated back
up to the requested velocity.
3.4.2

Velocity reduction according to overload factor

Function
This function lowers the path velocity in continuous path mode until the nontangential block
transition can be traversed in one interpolation cycle whilst respecting the deceleration limit
and taking an overload factor into account. With the reduced velocity, axis-specific jumps in
velocity are produced with a nontangential contour at the block transition. The jump in
velocity prevents the path velocity dropping to zero. This jump is performed if the axial
velocity was reduced with the axial acceleration to a velocity from which the new setpoint
can be reached with the jump.
The magnitude of the setpoint jump can be limited using an overload factor. Because the
magnitude of the jump is axial, the minimum jump of the path axes which are active during
the block change is considered during block transition. With a practically tangential block
transition, the path velocity is not reduced if the permissible axial accelerations are not
exceeded. In this way, very small angular changes in the contour can be overtraveled
directly.
Turning, Milling, Nibbling
Function Manual, 11/2012, 6FC5397-1CP10-5BA0
of the path axes. The block change is carried out when the "exact stop fine" of the
positioning spindle is reached.
Continuous Path Mode, Exact Stop and LookAhead (B1)
3.4 Continuous-path mode
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