Re: Kulago/Mauch DRO ISA quadrature feedback kit

["Matt Shaver" <mshaver-at-erols.com>]

> From: Doug Fortune <pentam-at-home.com>
> > > What maximum typical step rate can EMC produce on a
> > > 200 MHz (or 500Mz) Pentium?
<...>
> So I return to my original question: how many steps/sec can
> EMC pump out?   I think RTL has a limit of around 100,000
> interrupts per second (with a 500Mhz processor),  and these
> are probably shared among the 3 channels, so perhaps EMC
> can keep up with 30,000 steps/sec per channel.
> 
> Can anyone here with microstep drives confirm a higher
> step rate than 6,000/sec ?

>From a previous post of mine to the CAD_CAM_EDM_DRO list:

> > What step rate can be expected with the present EMC software?
> 
> It can step up to about 50kHz, but it's only usable (for me) up to 4-5kHz
> because each successive increasing step is larger than the last. Since
> stepper motor torque drops off as RPM increases, at some point the motors
> won't be able to make the jump to the next speed (frequency). I have a nice
> Excel spreadsheet that shows this effect if you're (or anyone is)
interested:
> http://users.erols.com/mshaver/stepfreq.xls

On a 350MHzP2 I could run with PERIOD = 11, you might do better on a
500MHzP3. Plug this number into the spreadsheet and you'll see the effect I'm
talking about.

Matt