Siemens sinumerik 840d Programming Manual page 167

04.00
5
840D 840D
NCU 571 NCU 572
NCU 573
Special case denominator polynomial
Command PO[]=(...) can be used to program a
common denominator polynomial for the geometry
axes (without specification of axes names), i.e. the
motion of the geometry axes is then interpolated as
the quotient of two polynomials.
With this programming option, it is possible to
represent forms such as conics (circle, ellipse,
parabola, hyperbola) exactly.
Example
POLY G90 X10 Y0 F100
PO[X]=(0,–10)
The constant coefficient (a
polynomial is always assumed to be 1, the specified
end point is not dependent on G90/G91.
The result obtained from the above example is as
follows:
X(p)=10(1–p )/(1+p
2
where 0<=p<=1
As a result of the programmed start points, end
points, coefficient a
values are as follows:
Numerator (X)=10+0*p–10p
Numerator (Y)=0+20*p+0*p
Denominator = 1+2*p+1*p
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SINUMERIK 840D/840Di/810D/FM-NC Programming Guide Advanced (PGA) − 04.00 Edition
810D 840Di
PO[Y]=(10) PO[]=(2,1)
) of the denominator
0
) and Y(p)=20p/(1+p )
2 2
and PL=1, the intermediate
2
2
2
2
5.4 Polynomial interpolation, POLY
Geometry axes traverse linearly to
position X10, Y0
Geometry axes traverse along quadrant to
X0, Y10
Y
10
Special Motion Commands
5
X
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