Re: Digest Number 3

> ______________________________________________________________
> _________________
>
> Message: 4
> Date: Sat, 8 May 1999 09:09:43 -0500
> From: "Steve Lindsay" <slindsay@...>
> Subject: Re: Digest Number 1 & homebrew DRO
>
> I didn't know that US Digital had a PC inerface card. This would
> be the way to go for a dro. Life is probably much similar
> this way

<snip>

>I would think an
> interface card
> would be faster
> and US Digital is probably doing a lot of the work on the
> hardware/interface
> that
> I was doing in code.

Steve,

This is correct. They buffer the incoming quadrature pulse train,
therefore it is very difficult to miss a pulse. I haven't been able to
out crank mine (the PC I'm using is a 16mhz 286!). They also do up to
(software selectable) 4x quadrature count on board.

>
> ______________________________________________________________
> _________________
>
> Message: 24
> Date: Sat, 08 May 1999 23:52:42 -0700
> From: garfield@... (Gar Willis)
> Subject: Re: interface board
>
> On Sat, 8 May 1999 20:10:15 -0500, "Steve Lindsay"
> <slindsay@...> wrote:
>
> >If US Digital has encoders to read from a linear strip this
> >would cure the problem of slippage.

This is correct.

>
> Well, they DO, but doggonit they (or you should really read
> "HP") don't
> have a linear resolution that in quadrature comes out to some nice
> English (or even Metric) quantum.

It is quite simple to apply any multiplier you wish in software. You can
have it read in cubits per degree it you want.

In the code I wrote you specify the unit of measure multipier, the
quadrture multiplier, etc. in a setup file.