On Sat, 22 Feb 2014, Sven Wesley wrote: > Date: Sat, 22 Feb 2014 10:12:08 +0100 > From: Sven Wesley <[email protected]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: "Enhanced Machine Controller (EMC)" <[email protected]> > Subject: [Emc-users] Preferred sensors for Mesa cards, NPN or PNP? > > I am going to shopaholic a bunch of proximity sensors to replace mechanical > homing and limit switches for two machines with Mesa cards (5i25/7i77) and > then it struck me, what is the best option? NPN or PNP? > How do they behave if there's no power to them or if they fail? For example > a PNP NO, is it open all the time or only open if the drive circuit has > power? What I am trying to grasp is what type of switch I should use to > trust the machine even if the switch fails (broken switch no operation). > > /Sven
for sinking inputs (like 7I70,7I76,7i77,7I84 field inputs) The best is NC PNP type. These will fail open (= limit) with short to ground or open wire faults > ------------------------------------------------------------------------------ > Managing the Performance of Cloud-Based Applications > Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. > Read the Whitepaper. > http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
