Path Jerk For Real-Time Events (Channel-Specific); General Information - Siemens SINUMERIK 828D Function Manual

B2: Acceleration
4.2 Functions
• Part program
• Static synchronized action
4.2.15

Path jerk for real-time events (channel-specific)

4.2.15.1

General Information

Overview
So that no compromise has to be made between machining-optimized jerk on the one hand and time-optimized
jerk in connection with the following real-time events on the other:
• NC-STOP / NC-START
• Changing the feedrate override
• Changing the velocity default for "safely reduced velocity" within the context of the "Safety Integrated" function
for the real-time events mentioned, the path jerk can be specified using a channel-specific system variable:
path jerk
$AC_PATHJERK =
Path jerk for real-time events will only be active for the duration of the change in velocity in respect of one of the
real-time events specified above.
Limiting
As the jerk is not a physical variable of any relevance to the drive, no limit is imposed on the jerk set.
Effectiveness
Effective Path jerk for real-time events is only enabled in AUTOMATIC and MDA operating
modes in conjunction with the following real-time events:
• NC-STOP / NC-START
• Override changes
• Changing the velocity default for "safely reduced velocity" within the context of
the "Safety Integrated" function
Not effective Path jerk for real-time events is ineffective for changes in the path velocity that are
attributable to path planning during preprocessing for the channel, such as contour
curvatures, corners, kinematic transformation limitations, etc.
Path jerk for real-time events is ineffective if the programmed value is smaller than
the path jerk calculated during preprocessing for the path section concerned.
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Function Manual, 09/2011, 6FC5397-0BP40-2BA0
Basic Functions