Re: [CAD_CAM_EDM_DRO] EMC Encoders

Ethan Vos wrote:

> Thanks for the info.
>
> Questions:
>
> When will your board be ready?

I'm hoping by the end of August, but that may be premature. I have a couple
of
other production jobs that need to be finished, too. The software conversion
needed so that EMC can talk to the auxilliary I/O through the real time
section (so that the two separate sections of the software don't step on each
other's toes) needs to be finished and tested.

> If I buy a new computer can I get an ISA slot?

Only if you make sure it has one, as very few new models do have them.

> What is the highest # of steps per second that EMC will support? I read in
> the Aug 11, 2000 release notes that it was 5,000, but that was dated July
> 14, 1999.

For software-generated step pulses, it depends on the CPU speed. I think
you can get 5000 steps/sec out of a 100 MHz Pentium with steppermod.o,
but freqmod.o would be slower. A 233 MHz pentium should be able to
do about 10000 steps/sec with freqmod.o.

With my board, it doesn't matter, as the CPU is NOT generating the step
pulses, just telling the rate generator how fast to make them. I have run it
up to 20,000 step/sec, but that is just the limit on my fastest stepper
driver.
It can go to,300,000 steps/sec on each axis.

>
> What would be the maximum on your board?

300,000 steps/sec, given normal settings for the setup and hold times on
the step/dir signals, and the step pulse width, which are all programmable.

> I have an existing machine with 1000 step/rev motors and 4 rev/inch lead
> screws. The limit of the lead screws is 10 inches per second which would be
> 40,000 steps/sec. If none of the above work, what's the next step?

Ahh, well it DOES sound like you might want to use software stepping in
the meantime, and wait for my board. by the time you've really gotten
everything
working together, I should have my board ready.

Jon