Siemens SINUMERIK 840D sl Function Manual page 162

Detailed description
2.2 Exact stop
Effects
If a block change cannot be executed in continuous path mode, all axes programmed in this
part program block (except cross-block traversing special axes) are stopped. In this case,
contour errors do not occur.
The stopping of path axes during machining can cause undercuts on the workpiece surface.
2.2 Exact stop
Exact stop or exact stop mode
In contrast to continuous path mode, in exact stop or exact stop mode, all path axes and
non-modal special axes involved in the traversing motion are decelerated until they reach a
standstill at the end of each block. The transition to the next block occurs only when all axes
involved in the traversing motion have reached their programmed target position with subject
to the selected exact stop criterion.
This results in the following response:
• All path axes and non-modal special axes involved in the traversing motion are
• The program run time is considerably longer compared to continuous path mode due to
• In exact stop mode, undercuts can occur on the workpiece surface during machining.
Use
Exact stop mode should always be used when the programmed contour must be executed
exactly.
Activation
Exact stop mode is activated in the part program by programming the following G-functions:
G function
G60
G09
10
decelerated at the end of the block until they reach a standstill.
the deceleration of the axes and the wait time until "Exact stop" status is reached for all
machine axes involved.
Meaning
Exact stop on, modal
Exact stop on, non-modal
Basic logic functions: Continuouspath Mode, Exact Stop, LookAhead (B1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0