I'm very new to CNC's. I received a SainSmart Genmitsu 3018 Pro as a gift, along with a few upgrade components for when I put it together (Y-axis extension kit, Aluminum Spoilboard, MYSWEETY 500w Spindle motor with power control, and Aluminum Spindle Holder).
My question is about the spindle power controller. It comes with a knob which apparently allows you to manually control the speed at which the spindle spins. Since I am so new to all of this I would rather that the computer/program decide what speed the spindle should be going. Is there a way to bypass this manual feature? Does the fact that the controller has connections for Mach3 have anything to do with this?
Sorry if this is a stupid question, but like I said, I'm VERY new to CNC's.
This is a link to the motor/controller that I received:

https://www.amazon.com/Spindle-Coole.../dp/B01LNBOCDA