Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 640)

Skip and Gauge probing Cycles
Chapter 19
19-2
ATTENTION: We do not recommend using a skip block from
any fixed cycle block (such as multi-pass face grinding or a
turning). If you do choose to execute a skip block in a fixed
cycle mode, be aware that the block that is skipped when the
trigger occurs can be a cycle generated block. If this is the case
the cycle will continue normal execution skipping only the
portion of the cycle that was executing when the trigger
occurred. If the generated block skipped is a crucial portion of
the cycle, damage to the part or machine tool can occur.
Use external skip functions to terminate the execution of motion
commands in a block when the control receives a signal through PAL.
When the program block is terminated any remaining axis motion
generated by the block that has not been performed remains unexecuted
(other non-motion commands are still performed). The control continues
normal program execution at the beginning of the next block following the
skipped block.
The external skip function is controlled by G31, G31.1, G31.2, G31.3, and
G31.4. Your system installer determines what signal (such as a touch
probe, manual switch, etc.) corresponds to each G31 code in PAL. Your
system installer can choose different signals to correspond to G31.2,
G31.3, and G31.4. G31 and G31.1 are functionally the same, always using
the same external signal and the same AMP defined feedrate. With proper
PAL programming, you can also use a G04 dwell in seconds as an external
skip function.
The format for G31 external skip blocks is:
G31 X__ Z__ F__;
Where : Is :
G31 any of the G codes in the G31 series or G04. Use the one that is configured to
respond to the current external skip signal device that is being used.
X, Z the endpoint of the move if no external skip signal is received. These also
determine the direction that the wheel travels in.
F the external skip function feedrate. If no value is entered here, the external skip
function executes at either the currently active feedrate, or the feedrate defined
for it in AMP (based on whether the AMP parameter Use AMP Skip Feedrate is
set to ”NO” or ”YES”). A value entered here replaces the currently active
feedrate and supersedes the AMP defined feedrate.
The G31 series of G codes always produces linear motion, regardless of
the current mode active at their execution. After their completion, the
control returns to the operating mode active before the external skip block
was read (G00, G01, G02, G03).
19.1
External Skip
Functions (G31 codes)