Rockwell Automation 999 IMC S Class Compact Motion Controller (Cat. No. 4100-999-122) - Manual (Page 117)

Understanding IMC-S/23x Setups 5-37
Publication 999-122 - January 1997
The usual answer to the Dual Loop Control? question is NO ,
which disables the special dual loop mode. To enable dual loop control
for this axis, toggle to
YES , and press ENTER. The servo control loop
with dual loop control enabled is shown below.
Once dual loop control is enabled for an axis (the dual loop axis), a
corresponding dual loop velocity axis must be selected. The encoder
input of the selected dual loop velocity axis is then used to close the
software velocity loop as shown in the figure above. Toggle to the
desired axis and press ENTER.
The axis selected as the dual loop velocity axis must not be the same
as the dual loop axis (the axis you are setting up) and must also be a
physical axis configured as
MASTER ONLY in the application setup
menu. If you select an axis which is not configured, the message
is displayed and you must select another axis.
!
ATTENTION: There must always be a physical
connection between the two feedback devices used
with a dual loop controlled axis or unpredictable
motion may occur!
*** This Axis is NOT CONFIGURED!