Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 571)

Cutter Diameter Compensation
(G40, G41, G42)
Chapter 21
21-53
Interference
This error occurs when compensation vectors intersect. Normally when
this intersection occurs, a backwards motion error is generated; however, a
few special cases exist that are caught only by interference error detection.
Figure 21.50
Typical Interference Error
Compensated path
Programmed path
Error is generated
because compensated
vectors cross
Compensated path
necessary
to cut arc
r
r
r
Disabling Error Detection
If so desired, all of the above error detection (with the exception of circular
departure-too-small cases) can be disabled for a specific block or portion
of a part program. To disable the error detection for a specific block, the
system installer must have defined an M-code in AMP. By programming
this M-code in a block, all error detection for cutter compensation may be
disabled. Error detection is disabled until another M-code defined in AMP
to re-enable error detection is programmed in a block.
Important: Circular departure too small cases cannot be disabled. The
control cannot execute a compensated path when this error occurs.
The default condition is error detection enabled. Default values for these
M-codes are:
M-code: Error detection:
M800 disables
M801 enables