Re: EMC problems

[John Sheahan <jrsheahan-at-optushome.com.au>]

> Fred,
> 
> I think you're PERIOD=0.00005 is still way too small. Try something like
> 0.005 and work your way to shorter period times. Make sure you have the
> decimal place in there.
> 
> - Keith

Suggested tuning for PERIOD

 50uS (sorry, do write it as 0.00005) was a number which worked for me
 on an ancient 150MHz pentium pro for freqmod.o
 16uS is too fast on that old box, locks, but would probably work fine on
 any current PC. 

 If the period is too small, computer will lock up. The timer interrupt
 service routine does not complete before a new one comes along.

 If the period is too big, motor control will be less smooth and
 velocity will be limited, but will run. 

 So to tune this, 
  decide which backend (steppermod.o or freqmod.o) you
 are using, 
 get it running with a nice safe PERIOD,  (numbers between
    PERIOD=0.005  and PERIOD=0.00005  appear to work 
 reduce PERIOD until things lock up, then reboot and
 double the number that just locks up for best performance.

can those that know more about this area please correct/improve the 
above method

john