Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 582)

Cylindrical Grinding Fixed Cycles
Chapter 17
17-8
If a plunge shift is made (G84 or G85), it is not made until the spark-out
passes are completed, the dither motion has stopped, and the plunge axis
has retracted to its start coordinate. As the plunge axis decelerates, the
plunge shift (Q) is executed.
Parallel Axes
Parallel axes can be used in the cylindrical grinding cycle blocks in place of
the primary axes to which they are parallel. For example, you can program:
G18;
G83Z__K__U__I__;
where the X axis has been replaced with its parallel axis, U. The integrand
for the X axis, I, is used for the U axis. The active plane becomes the ZU
plane where Z is axis 1 and U is axis 2 of the plane. The cycle begins with
a reciprocating move (Z axis) followed by a plunge move (U axis) of I,
made as the Z axis decelerates. See page 17-16 for details on the G83
cycle operation.
Block Displays while Executing Grinding Fixed Cycles
When executing part program blocks, the main screen of the control
displays a “*” before a block it is executing and a “@” before a block it
has completed. This is typical of any block executed on the control.
Be aware that when block execution involves the reciprocation axis, the
block may appear to be handled differently, but actually is not. What
frequently happens is that the “@” appears before a grinding fixed cycle
block and a “*” appears before the block that follows it even though that
block is being held in pre-block. It is being held while waiting for the
reciprocation axis to reach its secondary reversal point.
Similarly, the G-code display may show the G code of the following block
as active when, again, that block is being held in pre-block waiting for the
reciprocation axis to move to its secondary reversal point.
Cancel Grinding and Reciprocation
Use a G80 to cancel all cylindrical grinding cycles. Programming a G80
cancels a G81, G82, G83, G84, G85, G86, G87, G88, or G89. When
executed, a G80 also stops the reciprocating axis.