Aerotech UNIDEX 600 Series, User Manual

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Parameters U600 User’s Guide
C-44
Aerotech, Inc.
Version 1.4
C.2.101. VFF
This axis parameter enables or disables the Velocity Feed Forward portion of the servo
loop. Once enabled, this function minimizes the position following error. A one enables
this function, while a zero disables it.
C.2.102. VGAIN
This axis parameter scales the velocity command within the servo loop. VGAIN is used
only In tachometer based (velocity command) systems, VGAIN is multiplied by the
velocity command and added to the velocity command output to the servo amplifier. This
parameter is used to reduce position error during the constant velocity portion of the
move, (much like VFF would be used in a torque loop) by feed forward.
Note, that you can use the AutoTune feature, within the AerTune.exe utility (on the Tools
menu) to automatically determine servo loop gains for a torque mode axis.