Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 445)

Programming Feedrates
Chapter 18
18-19
When the corner angle, A, is larger than the value set for “min. angle for
corner override” in AMP, the programmed feedrate is overridden from
point “a” to point “b,” and from point “b” to point “c.”
The system installer sets these values in AMP:
Min angle for corner override -- minimum angle (A) between
programmed paths before corner override is activated
Corner override distance (DTC) -- vector distance from, and of current
move (b) to point on programmed path (a) where corner override is
activated
Corner override distance (DFC) -- vector distance from end of current
move (b) to point on programmed path (c) where corner override is
deactivated
Corner override percent -- amount that feedrate is to be reduced once
corner override is activated
To use an exact stop function while the automatic corner override mode
(G62) is active, use the G09 instead of the G61. This is because G61 and
G62 belong to the same G modal group and cancel each other if
programmed. Be aware that G09 is non-modal.
Your system installer has the ability to change the rate in which a spindle is
accelerated. AMP allows the option of either a 20 millisecond ramp (2ms
intervals) or an immediate step in spindle speed. By writing the
appropriate PAL your system installer may also in effect generate a spindle
“ramp” for even smoother spindle acceleration. Refer to documentation
prepared by your system installer.
In the default mode (G36), the Acc/Dec feature sometimes limits axis
feedrates far below the programmed feedrate. This occurs when the length
of axis motion in a block is short relative to the length of time necessary to
accelerate and decelerate the axis.
In the default mode (G36), the control limits the axis feedrate in any block
to the maximum speed from which it can properly decelerate to a stop
before that block ends. For example, consider the velocity profile of an
axis moving from Z4.8 to Z4.9 in Figure 18.11.
18.3.6
Spindle Acceleration (Ramp)
18.3.7
Short Block Acc/Dec Check
G36, G36.1