Mesa Card and Step Generation.

I'm trying to understand a few things in Linuxcnc with the Mesa 5i25 card.

Does the Mesa card only provide software step generation with steppers(without encoders), or hardware as well?
If software only, is there a difference between a Parallel Port vs. the Mesa card.

If I add encoders to the steppers what advantages will this provide with the Mesa 5i25 Card.

Thanks,
Ozcnc

All of our FPGA cards (5I25 included) provide hardware step generation

Encoders can be used for stall detection and linear scales can be used
for more accurate motion by using the step generator in velocity mode
and closing the position loop in linuxcnc

Will the step generation still be dependent on the latency of the pc in both cases.

Thanks
Ozcnc

Yes, but latency requirements are relaxed substantially, and the latency does not limit
the step generation rate but rather the following error.

Latencies in the 50-100 usec range are normally ok for hardware step generation,
and larger latencies (up to 200 usec at which point you will get real-time errors in a 1KHZ servo thread)
can be accommodated with specific tricks in the hal file setup.

Thanks,

Regards,
Ozcnc