User's Manual

PMAC User Manual
194 Writing Programs for PMAC
Line
Line
Line
Line
Programmed
Path
Tool Center
Path
Failure to See Through
Inside Corner
r
Overcut
Tool
Center Point
at Failure
r
r
Line
Line
Line
Line
Programmed
Path
Tool Center
Path
r
r
Arc
Tool
Center Point
at Failure
(No Overcut)
Failure to See Through
Outside Corner
Line
Line
Programmed
Path
Tool Center
Path
r
Stopping
Point
Arc Radius Smaller Than
Cutter Radius
Arc
Failures in Cutter Compensation
(Not
Executed)
Line
r
Line
Tool Center
Path
Line
Programmed
Path
Inside Corner Smaller Than
Cutter Radius
Overcut
Line
Line
Arc
r
r
Figure 49 Failures in Cutter Compensation
Inside Corner Smaller than Radius
Second, if the compensated path produces an inside corner with one of the moves shorter than the cutter
radius, the cutter compensation will not work properly. This situation results in a compensated move that
is in the opposite direction from that of the uncompensated move, and there will be over cutting at the
corner.
Inside Arc Radius Smaller than Cutter Radius
Third, if the program requests an arc move with compensation to the inside, and the programmed arc
radius is smaller than the cutter radius, then no proper path can be calculated. In this case, PMAC ends
the program at the end of the previous move with a run-time error, setting the coordinate-system run-time
bit in the status word to 1.
Single-Stepping While in Compensation
It is possible to execute moves in single-step mode while cutter compensation is active, but be aware of
several special considerations for this mode of operation. Because of the need for the program to see
ahead far enough to find the next move in the plane of compensation before the current move can be
executed, the execution of an S single-step command may not produce the intuitively expected results.
The single-step command on a move in compensation causes the preliminary calculations for that move to
be done, not for the move to be actually executed. This has the following ramifications:
• A single-step command on the lead-in move for compensation will produce no motion, because the
next move has not yet been found.
• Single-step commands on compensated moves in the plane of compensation will cause the previous
move to execute.
• A single-step command on the lead-out move will cause both the last fully compensated move and the
lead-out move to execute.