Re: [Emc-developers] Re: [Emc-users] pci motion control card

[Robin S. <li...@re...>]

On Wednesday 22 October 2003 18:53, Abdul R Rafiq wrote:
> I have designed a simple stepper pulse generator(divide by N type).  the
> output is described as:
>
> fout(in kHz) = (1000 / ((N + 1) x 2) ) x Clock (in Mhz)
>
> the counter is16bit.  65535 >= N >= 1
>
> with a 500khz clock, fout min is 3.8Hz, and fout max is 125Khz.  with 1 Mhz
> clock, fout min is 7.6Hz and max is 250khz.
>
> Is there a requirement of step rates below 3.8Hz or 7.6Hz in any
> application? 

not really .. so long as you can do a step and then output 0hz until the next 
step is required, thats fine .. imagine an XY stage doing a long line that 
has a slop of 1:100000, you would need say 1000hz on the X axis and 0.01 hz 
on the Y axis ... mostlikely you would output 0hz .. and then output Fmin for 
a few clock cycles unti one pulse has gone past, then 0hz again ...

> I dont think stepper motors work at very low step rates, but
> I may be wrong.

they work all the way down to DC, 1 step a year is just fine ... 

when is this board likely to be released? and (roughly) how much do you 
expect it to sell for?

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