Normal practice is short 2 terminals on the VFD , with a relay , to Start the Motor( usually Forward....not much need for Reverse ) and wire a variable 0-10Vdc signal from the BOB to the VFD to vary the speed of the motor.
Have you got the manual for the VFD? It should contain a diagram with Inputs and Ouputs wired to it as an example.
I'm not familar with the AXBBE, but someone who is will be along soon...
The AXBBE manual will have a similar diagram. Shouldn't be too hard to match them up.