EMC stepper pulse speed

Hi, I was reading the EMC site and saw in the begining they talked
about 5khz pulses for steppers with EMC, then later on when talking
about RT linux 20Khz was mentioned...

What are the realistic stepper pulse speeds attainable with EMC and
RT linux..

Also how consistant is the pulse train over this usable speed. Is is
a ragged pulse stream, or a smooth gradual stream that lends itself
to steppers.


WallyK


From EMC web site.....

"Stepper motor control is implemented using a second
real-time task that runs at 100 microseconds. This
task writes the parallel port output with bits set
or cleared based on whether the a pulse should be
raised or lowered. This gives an effective period
of 200 microseconds for a full up-and-down pulse,
or a 5 kilohertz frequency."


"Michael Barabanov and Victor Yodaiken of New Mexico
Tech modified the Linux source slightly, inserting
a real-time scheduler between Linux and the
hardware interrupts it used to receive. Now, your
code can run in the scheduler, with Linux running
when you're done. Tasks can run at cycle times down
to about 50 microseconds or so. That's 20 kilohertz
in real-time on your desktop PC."