Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 697)

Skip, Gauge, and Probing Cycles
Chapter 27
27-23
“Probe Trips During Deceleration” Warnings
An axis deceleration can occur before the probe trips caused by the
programmed endpoint of the G26 block being to close to the position at
which the depth probe trips. In this situation, the control having failed to
receive a probe fired indication, has begun to decelerate to the G26
programmed endpoint. During this deceleration the probe trips and
feedback is switched over to the adaptive depth probe. The warning
message “PROBE TRIP DURING DECL” is displayed. The axis then
begins accelerating to the location defined by the integrand word. This can
cause rough servo response as the feedback is switched from the axis
encoder to the depth probe during a deceleration. This error can also be
generated in subsequent G26 blocks after the adaptive depth probe is fired,
when the adaptive depth axis word is programmed in a G26 block in the
opposite direction that the integrand is requesting. See Example 27.2 for
details on correctly programming the axis word.
Probe trips during deceleration can also occur as a result of the control
thinking the G26 block is complete (axis within the in position band)
however the probe trip occurs while the following error is collapsing.
Solve this problem by moving the programmed endpoint of the adaptive
depth axis further into the part or use a lower feedrate to reduce following
error.
Unexpected Probe Trips
An error message is generated if the adaptive depth probe is not depressed
at the start of the block and it suddenly starts generating counts during
motion of a non G26 block in excess of the AMPed probe trigger tolerance
amount. When this unexpected probe trip occurs the control will enter
cycle stop. No axis deceleration ramp occurs for this condition. The total
probe deflection will equal the AMPed probe trigger tolerance plus the
existing following error for that axis at the point of the unexpected trip.
If the probe trips while the axis is performing a manual jog, the control will
display an error message. The axis will continue the jog unless the
maximum probe deflection is reached. The system installer determines the
maximum probe deflection in AMP. Manual jogs always use feedback
from the adaptive depth axis, not the adaptive depth probe.
Zeroing the Adaptive Depth Probe
Use this feature to create a zero point for your adaptive depth probe. The
adaptive depth probe only recognizes positive probe counts (those that
occur with deflection greater than the probe zero point).