Rockwell Automation GMLC Reference Manual - Manual (Page 314)

Publication GMLC-5.2 - November 1999
Position Lock CAM 277
Slaving to the Actual Position
When you select Actual from the Slave to menu, the actual position of the
master axis generates the position-lock cam motion on the slave axis, as
shown below.
Actual position is the current position of a physical or virtual master axis
as measured by its encoder or other feedback device. This is the usual
selection—and the only selection when the master axis is a master only
axis (physical or virtual)—because it is most often necessary to
synchronize the actual positions of two axes.
Slaving to the Command Position
When you select Command from the Slave to menu, the command
position of the master axis generates the position-lock cam motion on the
slave axis, as shown below.
Command position (only available when the master axis is a servo or the
imaginary axis) is the intended or commanded position of the master axis,
as generated by any previous motion blocks. Because virtual axes are
equivalent to physical master only axes, only actual position is available.
Slave Axis
Command Position Master Axis
Actual Position
Master Position
Position-Lock Cam
Slave Axis
Command Position Master Axis
Command Position
Master Position
Position-Lock Cam