On Thursday 19 March 2020 21:43:28 Peter C. Wallace wrote: > On Thu, 19 Mar 2020, Gene Heskett wrote: > > Date: Thu, 19 Mar 2020 21:33:22 -0400 > > From: Gene Heskett <[email protected]> > > Reply-To: "Enhanced Machine Controller (EMC)" > > <[email protected]> > > To: [email protected] > > Subject: Re: [Emc-users] A hal question? > > > > On Thursday 19 March 2020 19:03:27 Peter C. Wallace wrote: > >> On Thu, 19 Mar 2020, Gene Heskett wrote: > >>> Date: Thu, 19 Mar 2020 18:41:42 -0400 > >>> From: Gene Heskett <[email protected]> > >>> Reply-To: "Enhanced Machine Controller (EMC)" > >>> <[email protected]> > >>> To: [email protected] > >>> Subject: Re: [Emc-users] A hal question? > >>> > >>> On Thursday 19 March 2020 17:27:55 Peter C. Wallace wrote: > >>>> On Thu, 19 Mar 2020, Gene Heskett wrote: > >>>>> Date: Thu, 19 Mar 2020 17:02:59 -0400 > >>>>> From: Gene Heskett <[email protected]> > >>>>> Reply-To: "Enhanced Machine Controller (EMC)" > >>>>> <[email protected]> > >>>>> To: [email protected] > >>>>> Subject: [Emc-users] A hal question? > >>>>> > >>>>> Greetings; I am trying to reduce the f/r error in an ATS667 > >>>>> based encoder. > >>>>> > >>>>> The index pulse is turned upside down by a reversal of spindel > >>>>> direction. Tts the nature of the beast to remain in this stable > >>>>> state until the approach of the triggering ferrous metal causes > >>>>> the first reversal which the edge ignores, and then goes back > >>>>> true or false as the ferrous piece crosses the center. > >>>>> > >>>>> So I break into the index signal path with a comp looking at the > >>>>> velocity to generate an nearly instant direction signal and use > >>>>> it to diddle an xor which will restore the upside down index > >>>>> signal to same side up, this is then fed to an edge detector > >>>>> which fires on the positive going edge, giving a consistent to > >>>>> the degree reset back to the encoder regardless of spindle > >>>>> direction. > >>>>> > >>>>> Does anyone see any problems with that? The reversal of the > >>>>> pulse at the spindle reverse point should become the out of time > >>>>> and possible way early pulse that sets it up to actually trigger > >>>>> as the piece crosses the center of the ATS667. According to my > >>>>> thinking anyway. > >>>>> > >>>>> Poke it full of holes if I'm wrong. > >>>> > >>>> No index patching is needed as the index is only looked at when > >>>> going in one direction > >>> > >>> which I would naturally define as a + output at velocity-out? > >>> > >>> The text reads like it resets the counter to zero everytime this > >>> index pulse goes true, although that isn't stated, could be false. > >>> Confusing to be sure, so which edge is the active edge when > >>> waiting to start a G76 or G33.1? rising or falling? the first > >>> edge as the index piece is approaching could have have some timing > >>> error, while the 2nd edge as the pole piece crosses the centerline > >>> of the hall elements should be pretty accurate. > >> > >> At the FPGA pin the default index polarity is falling edge (but you > >> can change this with the index_invert pin) > > > > Doesn't exist. Or is this one of the fixes in the latest 7i90.zip? > > Its always been there > > on a 7i90 encoder 0 it should be > in a halshow this pin is invisible, but its not an error either!
setp hm2_7i90.0.encoder.00.index-invert true (or false, halshow says its done either way. How many other self-creating pins does this thing have? halshow reports this: setting parameter 'hm2_7i90.0.encoder.00.index-invert' to 'false' Parameter 'hm2_7i90.0.encoder.00.index-invert' set to false But it still does not show when clicking on encoder.00. Does anyone have an excedrin headache number for this? > > > Thank you Peter. Stay safe now. > > > > 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) > > If we desire respect for the law, we must first make the law > > respectable. - Louis D. Brandeis > > Genes Web page <http://geneslinuxbox.net:6309/gene> > > > > > > _______________________________________________ > > 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. > > > > _______________________________________________ > 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) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
