Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 611)

Cylindrical Grinding Fixed Cycles
Chapter 17
17-37
P -- dress program number
The number entered here must be a legal program number (a program that
has been saved as a subprogram or macro using the O word followed by a
number of up to five digits). This dress program is used for the pre-dress
operation. Refer to page 17-10 for details on the P word and it’s format.
A D word (number of pre-dressing operations) is not valid in this cycle. If
a D word is programmed with the dress program number, its value is
ignored for the G89.1 cycle but available for any other cycles activated
later in the part program that allow the D word.
Modal Parameters
Once programmed in the G89 cycle, the R plane, the two plunge distances
(I and Q), the distance of the blend move (K), and the medium (E), fine
(,F), and blend (,E) feedrates are modal in the G89 cycle. They need only
be programmed once while in the G89 mode. These modal parameters are
all cleared when the G89 mode is canceled.
Failing to Program Plunge Increment or their Feedrates
If you do not program a plunge increment or it’s corresponding feedrate,
they will default to zero and that plunge phase is skipped. For example if
you do not program a coarse plunge distance R, then the coarse plunge
phase is not performed. In this example, the rapid to R plane is extended
to the next programmed plunge start point (typically I). Programming a
zero for a plunge phase or feedrate also will result in that phase being
skipped (except F0 which is a single digit feedrate).
ATTENTION: Failing to program a clearance plane (R) in this
cycle will cause the control to skip the coarse plunge and rapid
to the end point of the next programmed plunge. For example,
if the medium plunge (I) is programmed but no R plane is
programmed the axes will rapid to the start point of the medium
plunge. Injury to the operator or damage to the machine can
occur. Any plunges distances not programmed will always be
performed at the feedrate of the previous plunge. If none of the
plunge phase increments are programmed, the axes will rapid to
the end point (shoulder point) of the cycle.