Rockwell Automation 8520-ARM2 9/Series CNC AMP Reference Manual Documentation Set - Manual (Page 583)

Probing Parameters
Chapter 31
31-5
Function
This parameter is used by both the G38 and G38.1 probing cycles.
Enter the distance from the start-point of the probing cycle to a point where
the feedrate is to be slowed. The feedrate should be slowed at a reasonable
distance from the expected end-point of the probing move to allow a more
accurate measurement of the axis position when the probe is fired. At this
point, the feedrate will slow from the Approach Feedrate “E” to the
Probing Feedrate “F”.
This parameter may also be entered directly in the probing cycle block of
the part program with an “R” word. If the “R” word is present in the
probing cycle block, the value entered here is ignored.
Axis Parameter Number
Single Process Process 1 Process 2
All [603] [20603] [21603]
Range
0.00000 to 99999.00000 mm
or
0.00000 to 3936.96850 in.
Notes
This is a per process parameter. The value set here applies to all axes
assigned to that process.
This parameter may also be changed on the control by using the fixed
cycle parameter table.
This parameter is for mill and surface grinder applications only.
31.5
Approach Distance (R)