Exact Stop Mode - Siemens SINUMERIK 828D Function Manual

B1: Continuous­path Mode, Exact Stop, LookAhead

3.2 Exact stop mode

3.2 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 Meaning
Exact stop with modal effect
G60
Exact stop with block-by-block effect
G9
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Function Manual, 09/2011, 6FC5397-0BP40-2BA0
Basic Functions