Something I just stumbled on then, page 5 shows drive specifications and in the step and direction part has max frequency: Differential motion 500Khz and open Collector 200Khz
With motor tuning set at, steps at 10,000 and vel. 2500 gives me 416,667 steps/second = 416Hhz, If the drive is reading in open collector mode that’s double its maximum.
Problem is I don’t know enough about it to know what the difference between differential and open mode is to say that’s it, nor how to change it.