Rockwell Automation 8520-GUM 9/Series CNC Grinder Operation and Programming Manual Documentation Set - Manual (Page 431)

Axis Motion
Chapter 12
12-59
Feedrate Override Switches Disable
An M49 causes the override amounts that are set by the switches on the
MTB panel to be ignored by the control. With M49 active, the override
switches for feedrate, rapid feedrate, and spindle speed are all set to 100%.
They can be enabled by programming an M48 (overrides enabled). See
chapter 10 for details.
Feedhold
Your system installer can write PAL to allow the activation of a feedhold
state through the use of a button or switch. When activated, the control
decelerates and hold the current feedrate for all axes to zero until the
feedhold state is deactivated. For details on using feedhold, refer to
documentation provided by your system installer.
The maximum allowable speed for each axis is set in AMP. If any axis
feedrate exceeds its maximum allowable speed, the control automatically
adjusts the feedrate to a value that does not cause axis speed to exceed its
set limit.
Figure 12.30
Feedrate Clamp
Z
X
F
F
XMAX
F
XMAX
: maximum X axis feedrate
F
ZMAX
: maximum Z axis feedrate
F
p
: programmed feedrate
F : actual feedrate
F
ZMAX
F
p
12159-I
In Figure 12.30, when the commanded feedrate is F
P,
it causes the Z-axis
feedrate to exceed the maximum feedrate (F
ZMAX
). The control then
adjusts the feedrate for both axes so that F becomes the actual feedrate.
When the feedrate is “clamped” to a value below the programmed feedrate,
the control displays a flashing C next to the current axis feedrate. The
displayed axis feedrate is the actual feedrate of the wheel, not necessarily
the programmed feedrate.
12.7.6
Feedrate Limits (Clamp)