RE: [CAD_CAM_EDM_DRO] Quadrature?

Here's a couple of links on quadrature encoding

In this link, scroll down to section 3, which has a pretty good description
of quadrature encoding:
http://www.seattlerobotics.org/encoder/200006/servo.html

http://mobots.com/EeC194/Notes/1999_10_21.html

Dave Hylands

> -----Original Message-----
> From: JanRwl@... [mailto:JanRwl@...]
> Sent: Friday, March 22, 2002 1:09 PM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: Re: [CAD_CAM_EDM_DRO] Quadrature?
>
>
> In a message dated 22-Mar-02 02:50:45 Central Standard Time,
> scotr@... writes:
>
>
> > Quadrature. So, what is it? And how should I approach
> it when starting
> > to set up a dro?
>
> Scott: Surely someone much wiser than I will answer this
> more "properly", but here's THIS ignernt old troll's
> answer to your question: "Quadrature" means when two
> "square-wave" signals are 90° out of phase with one-another.
> That is, the second channel (wave-form) CHANGES only when the
> OTHER channel (wave-form) is stable.
>
> These two signals (channels, wave-forms) are usually named
> "A" and "B". If "B" makes a transition from LO to HI when
> "A" is LO, then the (UP/DOWN-) counter counts 1 "UP".
> If "B" should make a transition from LO to HI when
> "A" is HI, then the (UP/DOWN-) counter will count 1 "DOWN".
> This way, the "electronics" can tell whether the encoder
> producing "A" and "B" is moving CW or CCW.