Hey Jim,
as you stated here, this jumper does not affect the serial communication between VFD and Onefinity Controller.
Nonetheless this jumper, which could not be found in the Huanyang Manual that can be found at Buildbotics or at Automation Technologies Inc., is of great importance for all who have a Huanyang VFD Model with a potentiometer on the Front panel:
A potentiometer can be connected to any VFD, but those models who additionally have a Potentiometer on the Front Panel they need a Jumper or something that lets you choose which potentiometer to use: The one on the Front panel, or the other that you wire to the Analog Terminal Inputs:
!
Source: Huanyang Manual, page 12.
Note that if you bought a VFD without potentiometer on the Front Panel, don’t worry, you can at any time connect a potentiometer to the Analog Terminals showed above.
So of course I saved well the information about the jumper you gave me, in order to make it available.