That unit was probabally well in excess of $1k, fortunately it has the manual, you will need it!
You will have to scale the command signal to the resultant frequency output, either in the control software or in the VFD parameters, Firstly, do you have a 4 pole motor? if so do you want to run it at 2x speed? (120hz)
To calibrate it, set the mechanical ratio to 1:1 set a speed in the software at the rated rpm of the motor, and then scale the s/w or VFD so that the frequency out is 60hz. The motor will then track the frequency above and below the normal operating Hz.
Any other mechanical ratio and you will have to calculate accordingly.