Siemens SINUMERIK 840Di Function Manual page 151

State of the machine axis
The state of a machine axis that refers to the position difference relative its setpoint position
at the end of a traversing motion is also designated as 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).
Parameter assignment
The tolerance windows of the exact stop criteria are specified with the following machine
data:
• MD36010 STOP_LIMIT_FINE (exact stop fine)
• MD36000 STOP_LIMIT_COARSE (exact stop coarse)
Fig. 2-1
Exact stop criterion: "Interpolator end"
With exact stop criterion "Interpolator end", the block change to the next block takes place as
soon as all path axes and non-modal special axes involved in the traversing motion have
reached the position programmed in the block in terms of the setpoint value. That is, the
interpolator has executed the block.
The actual position and the following error of the relevant machine axes are not taken into
consideration for exact stop criterion "Interpolator end". Thus, depending on the dynamic
response of the machine axes, this can result in a relatively large smoothing of the contour at
the block changes in comparison to the exact stop criteria "Exact stop coarse" and "Exact
stop fine".
Continuous-Path Mode, Exact Stop, LookAhead (B1)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Note
Tolerance window
The tolerance windows of the exact stop criteria "Exact stop coarse" and "Exact stop fine"
should be assigned such that the following applies: "Exact stop coarse" > "Exact stop
fine"
Tolerance windows of exact stop criteria
Detailed Description
2.2 Exact stop
2-3