Siemens SINUMERIK 840DE Programming Manual page 193

Continuous-path mode G64/G641 over several blocks
The following points should be noted in order to prevent an undesired stop in the path motion
(relief cutting):
Auxiliary function outputs trigger a stop (exception: high-speed auxiliary functions and
auxiliary functions during movements).
Intermediate blocks, which contain only comments, calculation blocks or subprogram calls
do not affect the movement.
Extensions of corner rounding
If FGROUP does not contain all the path axes, there is often a step change in the velocity at
block boundaries for those axes excluded from FGROUP; the control limits this change in
velocity to the permissible values set in MD 32300: MAX_AX_ACCEL and MD 32310:
MAX_ACCEL_OVL_FACTOR by reducing the velocity at block changes. This braking
operation can be avoided through the application of a rounding function, which "smoothes"
the specific positional interrelationship between the path axes.
Corner rounding with G641
You can activate a modal rounding action by programming G641 and specifying a rounding
radius with ADIS (or ADISPOS in rapid traverse). Within this radius about the block change
point, the control is free to ignore the path construct and replace it with a dynamically
optimized path. Disadvantage:Only one ADIS value is available for all axes.
Corner rounding with axial precision using G642
G642 activates corner rounding with modal axial tolerances. Corner rounding is not carried
out inside a defined ADIS area but theaxial tolerances defined with MD 33100:
COMPRESS_POS_TOL are maintained. Otherwise, the mode of operation is identical to
G641.
Fundamentals
Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
5.3 Continuous-path mode (G64, G641, G642, G643, G644)
Path Action
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