Siemens SINUMERIK 840D sl Function Manual page 1860

Detailed Description
2.4 Tool radius compensation 2D (TRC)
Part program:
$TC_DP1[1,1]=120
$TC_DP6[1,1]=10
N10 G0 X0 Y0 Z30
N20 G247 G341 G42 NORM D1 T1 Z0 FAD=1000 F=2000 DISCL=5 DISR=10
N30 X40
N40 X100
N50 Y-30
...
Example 2
The following conditions must be true for approach:
• Smooth approach is activated in block N20
• Approach movement performed with quadrant (G247)
• Approach direction not programmed, G140 is valid, i.e., because TRC is active (G41), the
contour is approached from the left
• Contour offset OFFN=5 (N10)
• Current tool radius=10, and so the effective compensation radius for TRC=15; the radius
of the SAR contour is thus equal to 25, with the result that the radius of the tool center
path is equal to DISR=10
• The end point of the circle is obtained from N30, since only the Z position is programmed
in N20
• Infeed movement
– From Z20 to Z7 (DISCL=AC(7)) with rapid traverse
– Then on to Z0 with FAD=200
– Approach circle in X-Y-plane and following blocks with F1500
The following conditions must be true for retraction:
• Smooth retraction is activated in block N60
• Retraction movement performed with quadrant (G248) and helix (G340)
• FAD not programmed, since irrelevant for G340
• Z=2 in the start point; Z=8 in the end point, since DISCL=6
• When DISR=5, the radius of SAR contour=20; that of the tool center point path=5
• After the circle block, the retraction movement leads from Z8 to Z20 and the movement is
72
(In order that this velocity becomes effective in the following blocks, the active G-code
G0 in N30 must be overwritten with G1. Otherwise, the contour would continue to be
machined with G0.)
parallel to the XY plane up to the end point at X70 Y0.
;Tool definition T1/D1
; Radius
Basic logic functions: Tool Offset (W1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0