Rockwell Automation 8520 9/Series CNC Lathe - Manual (Page 433)

Programming Feedrates
Chapter 18
18-7
Use on the MTB panel to override the
rapid feedrate for G00 mode in four increments:
F1 ---- percent value set in AMP by your system installer
25%
50%
100%.
Important: Normally this override is not active for any dry run motions
(see chapter 7) unless otherwise specified in PAL by your system installer.
Important: This override is also effective for jog moves that use the rapid
feedrate (see jogging using the button in chapter 4).
Feedrate override switches disable
An M49 forces the override amounts that are set with the MTB panel to be
ignored by the control. With M49 active, the overrides for feedrate, rapid
feedrate, and spindle speed are all set to 100 percent. You can enable them
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 holds 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.