Please follow the instructions below for adopting an AC motor drive for spindle motor control. 1. Wiring: PIN4 and PIN5 of the Delta CNC controllers are the spindle analog outputs. Please refer to the drawing below. 2. Parameter Setup: Parameter #399 needs to be set up as an analog spindle. Please see the screen shot below for an example of setting up the #399 Bit 0~5 as 10200.