Online Tool Offset; Defining A Polynomial Function (Fctdef) - Siemens SINUMERIK 840D sl Programming Manual

3.13.4

Online tool offset

3.13.4.1

Defining a polynomial function (FCTDEF)

Certain dressing strategies (e.g. dressing roller) are characterized by the fact that the grinding
wheel radius is continuously (linearly) reduced as the dressing roller is fed in. This strategy
requires a linear function between infeed of the dressing roller and writing the wear value of
each length. The linear function is defined using the predefined procedure FCTDEF(...) for up
to third order polynomial functions.
Straight line equation
y = f(x) = a
a : Gradient of the straight line, with a
1
a : Shift of the straight line along the X axis with a
0
Syntax
FCTDEF(<Func>,<LLimit>,<ULimit>,<a0>,<a1>,<a2>,<a3>)
Meaning
FCTDEF(...):
<Func>:
<LLimit>:
<ULimit>:
<a0>,<a1>,<a2>,<a3>:
NC programming
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0
+ a *x
0 1 1
Defining a polynomial function for PUTFTOCF(...):
y = f(x) = a
Function number
Data type:
Range of values:
Lower limit value
Data type:
Upper limit value
Data type:
Coefficients of polynomial function
Data type:
= Δx / Δy
1
= -a1 * X
0 V
+ a *x + a *x + a *x
2
0 1 2 3
INT
1, 2, 3
REAL
REAL
REAL
Work preparation
3.13 Tool offsets
3
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