Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Writing and Executing Motion Programs
299
When coming to a full stop (e.g. Step, Quit, /, or DWELL) at an outside corner with an added arc, Turbo
PMAC will include the added arc move before stopping. When coming to a full stop at an outside corner
without an added arc, Turbo PMAC will stop at the compensated, but unblended, corner point.
PMAC will include the added arc move before stopping. When coming to a full stop at an outside corner
without an added arc, Turbo PMAC will stop at the compensated, but unblended, corner point.
Treatment of Full Reversal
If the change in directed angle at the boundary between two successive compensated moves is 180
o
+ 1
o
(the included angle is less than 1
o
), this is considered a “full reversal” and special rules apply. If both the
incoming and outgoing moves are lines, the corner is always considered an outside corner, and an arc
move of approximately 180
move of approximately 180
o
is added. If one or both of the moves is an arc, Turbo PMAC will check for
possible inside intersection of the compensated moves. If such an intersection is found, the corner will be
treated as an inside corner. Otherwise, it will be treated as an outside corner with an added 180
treated as an inside corner. Otherwise, it will be treated as an outside corner with an added 180
o
arc
move.
Line
Programmed Path
Line
Line
Line
<1
o
Arc
Arc
Arc
Arc
Line
Programmed Path
Tool Center
Path Right
Path Right
Tool Center
Path Left
Line
Arc
Programmed
Path
Tool Center
Path
Arc
Arc
Arc
Arc
Programmed
Path
Tool Center
Path
Arc
Arc
Arc
Arc
Line to Line
Line to Arc,
Inside and Outside
Arc to Arc Outside
Arc to Arc Inside
Reversal In Cutter Compensation
Arc
r
r
r
r
r
r
r
r
Tool Center Path
Note on Full Circles
If a full-circle move is executed while in cutter compensation, and one or both of the ends produces a
shallow outside corner that is directly blended (no added arc – see Treatment of Outside Corners, above),
the compensated arc move will be extended beyond 360
shallow outside corner that is directly blended (no added arc – see Treatment of Outside Corners, above),
the compensated arc move will be extended beyond 360
o
, and Turbo PMAC may produce just a very
short arc, 360
o
shorter than what is desired (making it appear that the circle has been “skipped.”
Although typically this is the result of sloppy programming – an outside corner with a full circle causes
an overcut into the circle – many machine designers may want to permit slight cases of this. Coordinate
system parameter Isx97 defines the shortest arc angle that may be executed; the longest arc angle is 360
an overcut into the circle – many machine designers may want to permit slight cases of this. Coordinate
system parameter Isx97 defines the shortest arc angle that may be executed; the longest arc angle is 360
o
plus this angle.
The default value of Isx97 sets a minimum arc angle of one-millionth of a semi-circle, enough to account
for numerical round-off, but sometimes not enough for compensated full circles. To handle these cases,
Isx97 should be set to a somewhat larger value.
for numerical round-off, but sometimes not enough for compensated full circles. To handle these cases,
Isx97 should be set to a somewhat larger value.