Siemens SINUMERIK 840Di Function Manual page 261

Part program (excerpt, schematic)
; Setting of path acceleration and path jerk in the event of external intervention:
N0100 $AC_PATHACC = 0.
N0200 $AC_PATHJERK = 4. * ($MA_MAX_AX_JERK[X] + $MA_MAX_AX_JERK[Y]) / 2.
; Synchronized actions for the purpose of varying the override (simulates external
intervention):
N53 ID=1 WHENEVER ($AC_TIMEC > 16) DO $AC_OVR=10
N54 ID=2 WHENEVER ($AC_TIMEC > 30) DO $AC_OVR=100
;Approach
N1000 G0 X0 Y0 SOFT
N1100 TRANS Y=-50
N1200 AROT Z=30 G642
; Contour
N2100 X0 Y0
N2200 X = 70 G1 F10000 RNDM=10
N2300 Y = 70
N2400 X0
N2500 Y0
M30
Fig. 4-2 Switching between path jerk specified during preprocessing and $AC_PATHJERK
Acceleration (B2)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Examples
4.2 Jerk
4-3