Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 732)

Program Interrupt
Chapter 29
29-2
An error is generated if anything other than an N-word, a P- or L-word, a
block delete /, or a comment character is programmed in the M96 or M97
block.
An interrupt M-code M96 or M97 may also be programmed within a
interrupt program. If this is the case the interrupt does not become
enabled/disabled until the interrupt currently being executed is completed
and execution is returned to the main program.
Selecting the Type of Interrupt
These M-codes enable or disable two types of interrupt programs, which
we describe on page 29-5. You can use as many as 4 signals to PAL
(switches) to call interrupt programs. The system installer determines what
switch corresponds to which type of interrupt in PAL. Refer to
documentation prepared by the system installer for details on the types
available and switches used to control them for a specific machine
application.
The M-code determines which type and which switch signal is enabled or
disabled by programming an L-word with the M-code. There are 4
L-words:
L0 Interrupt type 1 Switch 0 triggers this
L1 Interrupt type 2 Switch 1 triggers this
L2 Interrupt type 2 Switch 2 triggers this.
L3 Interrupt type 2 Switch 3 triggers this
Program these L-words in each M96 or M97 block. Not programming the
L-word causes the control to assume an L-word of L0 has been
programmed. Refer to documentation prepared by the system installer for
the location and operation of the 4 switches.
If more than one L-word is programmed in a block, the right-most L-word
is the one that is used for that block. Other L-words in that block are
ignored.
Selecting an Interrupt Program
Any legal subprogram or paramacro may be selected as a interrupt
program (see chapter 10 on subprograms or chapter 28 for paramacros).
For a program to be used as an interrupt program it must have a program
name of 5 numeric characters following an O address (see chapter 10 on
program names). This interrupt program must contain an M99 block as the
last block in the interrupt program. This M99 block has all of the same
restrictions as an M99 block for a subprogram as described in chapter 10.