Exact Stop Mode - Siemens SINUMERIK 840D sl Function Manual

B1: Continuous-path mode, Exact stop, Look Ahead

4.2 Exact stop mode

4.2 Exact stop mode
Exact stop or exact stop mode
In exact stop traversing mode, all path axes and special axes involved in the traversing motion
that are not traversed modally, are decelerated at the end of each block until they come to a
standstill. 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:
● The program run time is considerably longer compared to continuous path mode due to
the deceleration of the axes and the wait time until "Exact stop" status is reached for all
machine axes involved.
● In exact stop mode, undercuts can occur on the workpiece surface during machining.
Status "Exact stop"
The state of the machine axis based on the position difference relative to its position setpoint
at the end of a traversing motion is also called an exact stop. The machine axis reaches the
"exact stop" state, as soon as its following error is less than the specified position difference
(exact stop criterion).
Application
Exact stop mode should always be used when the programmed contour must be executed
exactly.
Activation
Exact stop mode can be activated on a modal basis or in blocks in the part program:
G command
G60
G9
180
Meaning
Exact stop with modal effect
Exact stop with block-by-block effect
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Basic Functions