Re: EMC problem/question

Jon & Paul:

Jon, thanks for responding. I tried to fire up freqmod with some luck.

On 6 Aug, Paul wrote:
>
> Hi Jon
>
> Been playing around with the PERIOD parameter on a P166...
>
> 0.000016 - Instant reboot as soon as freqmod loads.
> 0.00016 - Freqmod loads, but the system then hangs.
> 0.0005 - Freqmod loads, Tkemc starts, and the axis will move. A
> snail will beat a G00 move.
>
> I know the computer is way under powered for freqmod, but it was
> fun trying to get it to work. Also found out what happens if the
> numbers are too small <g>

I just tried this on a 450MHz PIII. At values of PERIOD between 16 and
40 us I could get motion but it didn't seem right. It wasn't as smooth
as steppermod and would stop, buzz and lose steps at times. Some
values of PERIOD seem better but I didn't get a feeling a value could be
found to give "good" performance.

I tried a value of 10 us which nearly locked the machine. Once the
start-up hit "loading freqmod.o" it slowed to a snails pace. I closed
that window but this didn't speed things up, it was like the real time
process was still going. I was able to do a normal shutdown but even
this was very slow, all the way to power down.


For now I'll stay with steppermod and un-plug my opto-isolation
circuit. This is an easy way to solve the problem Jon pointed out. I
have a little more confidence in the hardware and am using an add on
ISA parallel port. So I feel OK running without opto-isolation. But
I'm sure I'll be back to freqmod later. :-)

Thanks.

Hugh Currin
Klamath Falls, OR