Oops.... Ray credited us with a feature the PMDX-122 does not provide. The PMDX-122 is buffered and will run Gecko drives even from a 3.3 volt parallel port, but it DOES NOT provide optical isolation for the input status signals. These signals do go through a buffer on the PMDX-122 that will, in most cases, protect the parallel port from damage due to signals applied to the status inputs. It does not isolate ground and thus cannot protect against damage due to external voltages arriving through the ground connection. Likewise for noise from equipment such as plasma cutters.
The folks at CANDCNC.com do offer an less expensive MiniIO card the does provide optical isolation, though you must buy another accessory card if you also want a relay. Regards, Steve Stallings PMDX > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of > [EMAIL PROTECTED] > Sent: Thursday, May 24, 2007 9:10 AM > To: [EMAIL PROTECTED]; Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] I/O card recommendations, please? > > > > > Hi Pat. Long time since we've heard from you. Glad to hear that > you're using EMC2 and that it is working for you. > > I've tried a lot of breakouts and the maker you mention is as > good as they come. The PMDX-122 is about as low cost as you find > for fully isolated. > > You might get away with just a screw terminal breakout if the > stepper drives you're using will handle raw parport output. Note > that Gecko drives will NOT work with a 3 volt parport sig. They > will work with some PCI parports that put out 5 volt. > > A search for "parallel port breakout boards" will get you a list > of 'em in just about the order I've worked with them. The only > one (passive) that I don't see there is a ziplink din rail mount > from automation direct. > > Hope this helps. Good luck. Report back with your progress and > (hint) add a page to the wiki with your projects. > > Rayh > > > > > On Wed, 23 May 2007 16:21:57 -0400, [EMAIL PROTECTED], > "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> said: > >Hi all, > > > >After the success I've had with EMC2 and my minimill, I've > decided to take a whack at converting a little Prazi 5x12 lathe I > have. So far I've got it "steppered" and I have procured a PC on > which I've installed EMC2 from the live CD. So far so good. > > > >On the minimill I'm using a PMDX i/o card with great success. > However, it occurs to me that for the lathe I am not going to > need much of the functionality of this card. (independant pulse > generation, high-current relays, etc.) > > > >It wasn't horrendously expensive (I want to say it was just over > $100) but I'm trying to do the lathe on the cheap, so I'm > wondering if anybody could suggest a less-expensive basic i/o > card that has only the optoisolators without all the extras. > Either preassembled or a kit wuld be fine. > > > >thanks, > >Pat > > > >================== > >Patrick Ferrick KA2AYK > >Town of Webb School > >Main Street > >Old Forge, NY 13420 > >(315) 369-3222 > >(315) 369-6216 (fax) > >================== > > > >------------------------------------------------------------------------- > >This SF.net email is sponsored by DB2 Express > >Download DB2 Express C - the FREE version of DB2 express and take > >control of your XML. No limits. Just data. Click to get it now. > >http://sourceforge.net/powerbar/db2/ > >_______________________________________________ > >Emc-users mailing list > >Emc-users@lists.sourceforge.net > >https://lists.sourceforge.net/lists/listinfo/emc-users > > > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
