Siemens SINUMERIK 840D sl Function Manual page 163

Exact stop criteria "Exact stop coarse" and "Exact stop fine".
The two exact stop criteria "Exact stop coarse" and "Exact stop fine" are used to specify the
applicable tolerance window for reaching the "Exact stop" state of a machine.
Machine axis state
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 $MA_STOP_LIMIT_FINE (exact stop fine)
MD36000 $MA_STOP_LIMIT_COARSE (exact stop coarse)
Note
Tolerance window
The tolerance windows of the exact stop criteria "Exact stop coarse" and "Exact stop fine"
should be so assigned, that the following requirement is fulfilled:
"Exact stop coarse" > "Exact stop fine"
Figure 2-1
Basic logic functions: Continuouspath Mode, Exact Stop, LookAhead (B1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Tolerance windows of exact stop criteria
Detailed description
2.2 Exact stop
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