Re: EMC configuration help

["Ian Wright" <Ian-at-iw63.freeserve.co.uk>]

Hi Ray (and other 'experts'),

I am a bit confused by how the INPUT SCALE and OUTPUT SCALE values work.
Initially I assumed that they work just as you described but, when I set up
my copy of EMC to work in Metric mode I found that this seems not to be. The
way I have mine set up is with UNITS = 1 and INPUT SCALE = 1200 which
represents a 1mm pitch screw driven through a 3:1 belt reduction from a 200
step motor in half-step mode (400 half steps x 3 x 1 = 1200). However, if I
have OUTPUT SCALE also set to 1200, the display reads ten times too high
(1/10th mms) so I have it set to 120.000 - the display reads right in whole
millimetres and the machine still moves the right amount - so, in this case,
the setting of OUTPUT SCALE seems only to affect the way the readout appears
on screen and not the number of pulses the PC sends out.

----- Original Message -----
From: "Ray" <rehenry-at-up.net>
> >
> > What do the _two_ numbers represent? Why use INPUT_SCALE (I do not
> > have feedback via DRO)?
>
> I think that the appropriate way to think of these is that the input scale
> represents how many pulses you need to input to the motor amp to get one
> unit of motion.  Output scale is the number of pulses the encoder will
> send for one unit of motion.  Motor or axis in and out rather than PC in
> or out.


Ian
--
Ian W. Wright
Sheffield  UK
www.iw63.freeserve.co.uk