The easiest place to start would be:
- See what the maximum speed your spindle can get to when controlling it with the SLB then note that value down
- See what the minimum speed is that you can get to and note that down
- Update the firmware values for that minimum and maximum speed
- Power-cycle the SLB, then try again to see if it now matches up at least for the Min and Max values. If not, go through the process again until the min and max values line up - at that point the remaining values should also now be fairly close