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
0
+ a
1
*x
1
a
1
: Gradient of the straight line, with a
1
= Δx / Δy
a
0
: Shift of the straight line along the X axis with a
0
= -a1 * X
V
˂\
˂[
<
;
;
9
Syntax
FCTDEF(<Func>,<LLimit>,<ULimit>,<a0>,<a1>,<a2>,<a3>)
Meaning
FCTDEF(...): Defining a polynomial function for PUTFTOCF(...):
y = f(x) = a
0
+ a
1
*x + a
2
*x
2
+ a
3
*x
3
<Func>: Function number
Data type: INT
Range of values: 1, 2, 3
<LLimit>: Lower limit value
Data type: REAL
<ULimit>: Upper limit value
Data type: REAL
<a0>,<a1>,<a2>,<a3>: Coefficients of polynomial function
Data type: REAL
Work preparation
3.13 Tool offsets
NC programming
Programming Manual, 12/2019, 6FC5398-2EP40-0BA0 751

Siemens SINUMERIK 840D sl Specifications

General

Control Type	CNC
Number of Axes	Up to 31
Max Number of Channels	10
Interfaces	Ethernet, PROFIBUS, PROFINET, USB
Interpolation	5-axis interpolation
Operating Temperature	0°C to 45°C
Relative Humidity	Up to 95% (non-condensing)
Display	TFT color display, various sizes
Programming Languages	DIN/ISO
Safety Features	Safety Integrated
PLC	Integrated PLC S7-300
Drive Interface	SINAMICS S120
Data Storage	CF card, USB
Operating System	Windows-based