Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 734)

Program Interrupt
Chapter 29
29-4
The system installer determines:
- in AMP, if a signal to execute an interrupt program is delayed
until the end of a currently executing block, or executed
immediately.
- in AMP, whether an interrupt program request is recognized
when an interrupt switch is turned on, or only when the switch
makes the transition from off to on. This helps prevent the
accidental execution of an interrupt program.
- whether to write PAL to allow the use of 4 interrupt signals (4
switches). One of these signals can call a type 1 interrupt; the
other three call a type 2 interrupt.
Interrupt programs:
- should normally be disabled during thread cutting. The execution of
an interrupt program during a threading pass can cause undesired
results.
- can only be executed when the control is in the automatic mode.
Interrupt requests that occur during MDI or manual modes are
ignored.
Consider tool tip radius compensation during an interrupt request:
Compensation
Status:
The Status Remains:
Active (G41 or G42) Active throughout execution of the interrupt unless canceled
with a G40. Different tool radii (selected with a T-word) and
different compensation directions (G41 or G42) can be
programmed in the interrupt program. It is the programmer’s
responsibility to make sure the correct compensation direction
(G41, or G42) is active and the correct length and radius offset
is active (as programmed with the T-word) before the M99
return from interrupt command is executed.
Not Active Can be activated by programming either a G41 or G42 in the
interrupt program. Compensation must be turned off with a
G40 in the interrupt program before the M99 return block is
executed.
29.2
Interrupt Request
Considerations