Siemens SINUMERIK 840D sl Function Manual page 168

Detailed description
2.3 Continuous -path mode
• If a synchronized axis is programmed that was last programmed as a positioning axis or
• If the transformation is changed, the block previously processed is terminated with the
• A block is terminated on interpolator end if the following block contains the switchover of
• If the "empty buffer" function is programmed, the previous block is terminated when the
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:
• Positioning axes have been programmed with syntax POS and have a travel time that
• The time taken to position a spindle programmed with syntax SPOS is longer than the
• The current block contains traversing commands for geometry axes and the following
• Synchronization is required
Auxiliary function output during traversal
In continuous-path mode with auxiliary-function output during motion and short traversing
blocks, the path velocity is decelerated prior to PLC acknowledgment of the auxiliary
functions.
The axes are decelerated to standstill respecting the acceleration limits at the end of the
block. At the end of the block acknowledgment is awaited before motion can continue.
Acknowledgment during deceleration
Acknowledgment during deceleration accelerates the velocity back to the programmed path
velocity.
In order to prevent this happening in continuous-path mode, the following machine data can
be used to set a time for the CNC during which the PLC will safely acknowledge the auxiliary
functions for the CNC:
MD10110 $MN_PLC_CYCLE_TIME_AVERAGE (average PLC acknowledgement time)
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spindle (initial setting of the special axis is positioning axis), the previous block is ended
at the interpolator end.
active exact-stop criterion.
the acceleration profile BRISK/SOFT.
For more information about BRISK and SOFT:
Reference:
/FB1/ Function Manual basic function; acceleration (B2)
selected exact-stop criterion is reached.
exceeds that of the path axes. Block change occurs when the "exact stop fine" of the
positioning axes is reached.
travel time of the path axes. The block change is carried out when the "exact stop fine" of
the positioning spindle is reached.
block traversing commands for synchronized axes or, alternatively, the current block
contains traversing commands for synchronized axes and the subsequent block
traversing commands for geometry axes.
Basic logic functions: Continuouspath Mode, Exact Stop, LookAhead (B1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0