Centroid Community CNC Support Forum

I have a small 704 mill with a 1100 watt BLDC spindle motor that uses a power supply and push button controller converted to cnc using the acorn and am trying to add spindle control to it using the cnc12 . I have watched all the videos on spindle set up but for the life of me its unclear if I need both the kb controller with a signal isolator SI-5 as my current board has provisions for external control Thanks in advance for any help