Siemens Sinumerik 840D sl Programming Manual page 502

Path traversing behavior
8.8 Programmable contour/orientation tolerance (CTOL, OTOL, ATOL)
Further information
Read tolerance values
For more advanced applications or for diagnostics, the currently valid tolerances for the
compressor functions (COMPON, COMPCURV, COMPCAD), the smoothing types G642,
G643, G645, OST, and the orientation smoothing ORISON can be read via system variables
irrespective of how they might have come about.
• In synchronized actions or with preprocessing stop in the part program via system
variables:
Note
If no tolerance values have been programmed, the $A variables will not be differentiated
sufficiently to distinguish potential differences in the tolerances of the individual functions,
since they can only declare one value.
Circumstances like this can occur if the machine data and the setting data set different
tolerances for compressor functions, smoothing and orientation smoothing. The variables
then return the greatest value prevailing with regard to the currently active functions.
if, for example, a compressor function is active with an orientation tolerance of 0.1° and
ORISON orientation smoothing with 1°, the $AC_OTOL variable will return the value "1". If
orientation smoothing is deactivated, only the value "0.1" will remain to be read.
502
$AC_CTOL
$AC_OTOL
$AA_ATOL[<axis>]
Contour tolerance effective when the current main
run record was preprocessed.
If no contour tolerance is effective, $AC_CTOL will
return the root from the sum of the squares of the
tolerances of the geometry axes.
Orientation tolerance effective when the current main
run record was preprocessed.
If no orientation tolerance is effective, $AC_OTOL will
return the root from the sum of the squares of the
tolerances of the orientation axes during active
orientation transformation. Otherwise, it will return the
value "-1".
Axis tolerance effective when the current main run
record was preprocessed.
If no contour tolerance is active,
$AA_ATOL[<geometry axis>] will return the
contour tolerance divided by the root of the number of
geometry axes.
If an orientation tolerance and an orientation
transformation are active
$AA_ATOL[<orientation axis>] will return the
orientation tolerance divided by the root of the
number of orientation axes.
Programming Manual, 02/2011, 6FC5398-2BP40-1BA0
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