gmane.linux.distributions.emc.user

tomp | 4 Dec 10:06

Re: How can I calculate the INPUT_SCALE value?

john,

i wasnt aware that emc used floats ther
it is unusual in cnc to do so, but thats an observation

the 'nice number' refers to the numerator and denomimator
which are outside if emc
which are inside the driver

unless these 2 are nice numbers ( ints divisible by 4 )
then the home pulse delivered to control is longer than the real home pulse
this can lead to trouble in homes that do not coincide always.
when both are ints divisble by 4, then the home pulse is same size as 
mfctr intended

floating point has to do with emc
nice numbers have to do with driver

integer counts per user unit of measure might be an advantage to emc
because most cnc manufacturers use integers there (Fanuc Heidenhain )
and there are some that use floats (PMAC EMC )

the general public (non-emc?) would think ints when thinking counts per 
unit of measure

fwiw
tomp

John Kasunich wrote:
> tomp wrote:

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Alex Joni | 4 Dec 15:35

Re: How can I calculate the INPUT_SCALE value?

Hi Tom,

I think it's an unnecessary loss of precision to use ints for the SCALE.

> the general public (non-emc?) would think ints when thinking counts per
> unit of measure

I use numbers like "21747792.6624" on some commercial robot controls I work 
on, using ints there would probably hurt especially with the kinematics 
calculations.

Since it already does floats, I see no reason to "dumb" it down  ;)

Regards,
Alex

----- Original Message ----- 
From: "tomp" <tomp-tag@...>
To: "Enhanced Machine Controller (EMC)" <emc-users@...>
Sent: Thursday, December 04, 2008 11:06 AM
Subject: Re: [Emc-users] How can I calculate the INPUT_SCALE value?

> john,
>
> i wasnt aware that emc used floats ther
> it is unusual in cnc to do so, but thats an observation
>
> the 'nice number' refers to the numerator and denomimator
> which are outside if emc
> which are inside the driver

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