[CAD_CAM_EDM_DRO] Re: Controlling VFDs from your PC?

Group,
Coming from a lightweight in electronics and software... The hardware may
be the easier part here. A DAC would be the most logical thing to use.
However, if one is using a proprietary CNC system, it may be difficult or
impossible to interface the software to the newly added DAC hardware. I'd
propose a crude system of using a M function port to output pulses to a ttl
counter which in turn feeds a DAC or resistor network to control the VFD.
Perhaps each pulse would add 125 RPM?

When the spindle is stopped, it would reset to zero. Of course if you have a
5000 rpm spindle, you may want to increase the size of the steps. Many CNC's
allow program loops, it would be easy to loop however many times needed to
get the desired speed. It's horribly crude but between a few M functions,
you could control spindle on / off, direction and speed.


Peter
THRD, Inc.


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