RE: RTLinux vs RTAI and EMC

["Tim Goldstein" <timg-at-ktmarketing.com>]

Dale,

If you take a 500 line encoder (not a particularly high resolution) that
gives you 2000 steps per motor rev. Now is you have 2:1 belt reduction
(very common. But on the low side for most servos motor for best
performance) that puts you at 4000 steps per screw turn. Now if you are
using 10 tpi acme screws (again a common setup) you now have 40000 steps
per inch of travel. So if you want only 60 ipm you need 40 kHz.
Certainly not a very impresive rapid rate, but sure will push freqmod.

Tim
[Denver, CO]


> -----Original Message-----
> From: emc-at-nist.gov [emc-at-nist.gov] On Behalf Of Dam
> Sent: Sunday, June 09, 2002 10:44 PM
> To: Multiple recipients of list
> Subject: Re: RTLinux vs RTAI and EMC
> 
> 
> 
> Tim,
> 
> I've done some testing of freqmod on an AMD K6-2  450 Mhz.  
> With period 
> set at 0.000016 the pulses on my scope sure look like 16us 
> high and 16us 
> low, that figures to be 31.25k Hz. How fast do you need?  I'm still 
> trying to figure out the ini parameters for using my own step & 
> direction servo drive.
> 
> Dale
> 
> Tim Goldstein wrote:
> 
> >Ray,
> >
> >Unless the speed of freqmod can be drastically increased then 
> >steppermod is needed for step and direction servos (Gecko, Mr Bill, 
> >Rutex).
> >
> >Tim
> >[Denver CO]
> >
> >
> >>Do you really need steppermod.  Freqmod will work nearly as
> >>well but not 
> >>quite as fast.
> >>
> >
> >
> >
> >
> >
> 
> 
> 
>