Siemens SINUMERIK 840Di sl Programming Manual page 216

Path Action
5.4 Acceleration behavior
(axis1,axis2,...)
Note
A change between BRISK and SOFT causes a stop at the block transition. The acceleration
pattern for the path axes can be defined in machine data.
Apart from the path-related jerk limitation that is effective in the MDA and AUTO modes,
there is the axis-related jerk limitation that can influence positioning axes and traversing axes
in JOG mode.
Example of BRISK and SOFT
N10 G1 X... Y... F900 SOFT
N20 BRISKA(AX5,AX6)
216
The acceleration pattern set in machine data $MA_POS_AND
JOG_JERK_ENABLE or $MA_ACCEL_TYPE_DRIVE is active for
the programmed axes.
Programming Manual, 11/2006, 6FC5398-1BP10-2BA0
Fundamentals