On Monday 13 April 2015 14:37:36 Rick Lair wrote: > I have plenty room really, I just don't have the slightest idea what > resistor to use, I know how to get it wired into the system, but not > the nearest clue as which ones to order. > > Thanks > > Rick
That should be relatively easy, but dependent on the noise environment which can be considerable in the general machine shop setting. Assume you think 1 milliamp is a low enough impedance to absorb the noise, then 3.3 volts would mean the resistor to ground from the card input would be 1/.001 x 3.3 = 3.3kohms. Then you want a drop of 5.0-3.3=1.7 volts, so the same mental math gets you 1700 ohms. The nearest value in the grand scheme would be 1800 and entirely suitable. Nice well shielded wiring in a star ground configuration and you could save some power by multipling the above by 10, cutting the current consumption to 100 microamps if the 5 volt refrence is a little puny. At these voltage and currents, any resistor you can physically handle is more than sufficient to handle the job power rating wise. On balance however and knowing the keyboard matrix is in that card (thanks Peter), I would automaticaly choose that option as it gives you the possibility of adding even more tally switch inputs later, while leaving the A/D inputs for future use also, thereby future proofing your hardware design considerably. IOW, do not build a needless, restrictive wall around this by useing an A/D input for a switch. YMMV of coarse. > On 4/13/2015 2:06 PM, Dave Cole wrote: > > Just an alternative idea... run a single thin Cat 5 stranded cable > > back to the 7i70 and forget about it. > > > > If you go with pullup resistors, they can be done nicely on a > > terminal strip (multilevel is best) but that takes space and I don't > > know how much you have. > > > > Dave > > > > On 4/13/2015 11:26 AM, Rick Lair wrote: > >> What would be the best course of action to utilize 0-7 for inputs > >> like this, I am using every available input on the 7i73, instead of > >> dragging a bunch of wire through the pendant arm, back to the 7i70 > >> in cabinet? > >> > >>> Yes they are available as both analog and digital inputs, however > >>> inputs 0 through 7 have no pull-up or pull-down resistors so are > >>> a bit awkward to use with switches. > > > > --- > > This email has been checked for viruses by Avast antivirus software. > > http://www.avast.com > > > > > > -------------------------------------------------------------------- > >---------- BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM > > EDT Develop your own process in accordance with the BPMN 2 standard > > Learn Process modeling best practices with Bonita BPM through live > > exercises > > http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- > > event?utm_ > > source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_ > >SF _______________________________________________ > > Emc-users mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-users 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> ------------------------------------------------------------------------------ BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT Develop your own process in accordance with the BPMN 2 standard Learn Process modeling best practices with Bonita BPM through live exercises http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_ source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
