On Monday 07 July 2014 10:32:44 Peter C. Wallace did opine And Gene did reply: > On Sun, 6 Jul 2014, Gene Heskett wrote: > > Date: Sun, 6 Jul 2014 12:58:28 -0400 > > From: Gene Heskett <[email protected]> > > Reply-To: EMC developers <[email protected]> > > To: [email protected] > > Subject: [Emc-developers] 5i25/7i78 question > > > > Greetings; > > > > I am considering, because of the quantization noise in the software > > encoder output, switching my lathe to the 5i25-7i78 combo as it can > > do much higher frequency sampling of the ABZ signals. > > > > However when I dl'd the pdf manual, I find its stepper outputs can > > only source or sink 10 mills when 1 volt away from the supply rails. > > > > My present BOB, a cnc4pc C1G, can do very close to rail to rail while > > sourcing or sinking 24 mills. > > The only real difference between the C1G and the 7I78 outputs is that > the 7I78 has 27 Ohm series resistors in its 74ACT buffer output pins > (and that the 7I78 has differential outputs) It should drive any > step/dir input just fine The 2M542's inputs are fully isolated opto's.
> If you use the outputs single ended you will get twice as much drive > (but ~1/3 the noise immunity) > I don't believe the C1G can do differential output w/o sacrificing pins. OTOH, there are only 2 steppers on the lathe, so I could, but 4 on the mill. So at some point, when I run out of current projects, you'll see an order from me for another 5i25 and a pair of 7i78's. I assume PncConf will by then support the 7i78? Its been a couple months since I ran it, but don't recall seeing the 7i78 in the menu's presented. Thanks Peter. Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
