Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 731)

Program Interrupts and
Dressing Interrupts
Chapter 22
22-11
In addition to auto-dress as described on page 22-10, grinding cycles for
both cylindrical and surface grinders can be defined to have a pre-dress
feature (identified by the decimal point following the cycle G code, i.e.
G8n.1). Grinding cycles with pre-dress automatically perform a dressing
interrupt before the cycle motions begin, including reciprocation.
The program called for by this pre-dress interrupt is also defined in the
cycle block with the P word. See chapters 16 and 17 for details on which
grinding cycles have pre-dress and their block formats.
During reciprocation or any grinding cycle, dressing interrupts are
executed at the end of the currently executing motion. The current
reciprocation move, and any motions normally generated by the cycle at
this reversal point (any pick, plunge, or dither motions), are decelerated to
their endpoints. The endpoint of reciprocation is either the primary or
secondary reversal point. Once at the endpoint with axis motion stopped,
the interrupt program is executed.
When dressing interrupts are complete, the control returns the wheel to the
same point in the calling program that it was at when the interrupt was
performed (same as type 2 program interrupts).
Normally, the first 4 linear moves (G00 or G01) in the interrupt program
are remembered and retraced when returning to the calling program. This
can be altered by programming a specific M code as discussed later. If a
non-linear (G02 or G03) circular move is performed as one of the first four
blocks of the interrupt, the control remembers only the moves up to that
block. If a circular block is the first block in the interrupt, then the
start-point of that block is all that is remembered. In this case, the control
returns the wheel to the part in a linear move to that start point.
22.2.3
Dressing Interrupt through
Pre-Dress Request
22.2.4
Dressing Interrupt
Execution