Just ordered some wire and am going to send it to the 7i70. Rick
On 4/13/2015 3:02 PM, Gene Heskett wrote: > 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 -- Thanks Rick Lair Superior Roll & Turning LLC 399 East Center Street Petersburg MI, 49270 PH: 734-279-1831 FAX: 734-279-1166 www.superiorroll.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
