Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 736)

Program Interrupts and
Dressing Interrupts
Chapter 22
22-16
If an interrupt occurs during a block retrace, the interrupt is performed.
The block retrace is aborted at that point and no further retrace is
allowed. Block retrace still returns any moves that have already been
retraced before the interrupt occurred.
When an interrupt request is performed, the control will decelerate the
axis to a stop. If there is not enough distance remaining in the block to
properly decelerate the axis, the control will perform any remaining
deceleration in one 20ms step at the end of the current block (often
causing overcutting or excessive machine loading). This condition is
not typical since normal acc/dec limits feedrate so there is always
enough block to properly decelerate the axis. In cases when the normal
acc/dec feedrate check is disabled (G36.1 mode for very short blocks)
this occurrence can be much more frequent.
END OF CHAPTER