Originally Posted by
PCW_MESA
On typical drives there will be random latency in the 10 to 50 microsecond region. It typically cannot be much less than this because the
actual change in stepper drive voltage has to wait for the next (asynchronous) chopper or PWM cycle. (and these typically are in the 50 KHz region or slower).
The slow change in step motor current in response to this voltage change will further slow the actual torque response to the step input.
There may also be significant constant latency on drives that have (enabled) features like step "smoothing"
This makes little practical difference since even a 50 usec timing difference will not make a significant addition to a step motor
driven CNC machines error budget.