they are strictly talking about using quadrature instead of step-direction as the interface between the card and the stepper drive.. Instead of the direction pin designating which direction the stepper would go - it looks at which signal rises or falls first. Very noise tollerant.
Same way you know which direction an encoder is spinning and how far it has rotated. sam ----- Original Message ----- From: "Gene Heskett" <[EMAIL PROTECTED]> To: <[email protected]> Cc: "Jon Elson" <[EMAIL PROTECTED]> Sent: Thursday, February 15, 2007 2:44 PM Subject: Re: [Emc-users] Hardware step generator for 5I20 > On Thursday 15 February 2007, Jon Elson wrote: >>[EMAIL PROTECTED] wrote: >>>"Peter C. Wallace" <[EMAIL PROTECTED]> wrote: >>>>Step/DIR or quadature output selectable per generator. >> >>My UPC has had quadrature output available since I developed it. I >>don't think more >>than one user actually used the feature, and he was using an absolute >>minimum >>driver, just power transistors. But, yes, it seems to have significant >>advantages >>over step/direction! >> >>Jon > > Generally I have to agree Jon, as the smoothest, most accurate mouse any > of us has ever used was the decoded quadrature output amiga mouse of > yesteryear, but it comes to mind, how does one handle the microstepping > when using the quadrature signals if you can't step back and forth > through the lookup table of desired currents using that? > > That would also seem to restrict you to 1/4 step resolutions unless the > lookup table was two full cycles wide. Then one almost needs an index > pulse too... > > Or am I miss-understanding the actual implementation? > > -- > Cheers, Gene > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > Yahoo.com and AOL/TW attorneys please note, additions to the above > message by Gene Heskett are: > Copyright 2007 by Maurice Eugene Heskett, all rights reserved. > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share > your > opinions on IT & business topics through brief surveys-and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
