On Thu, Nov 29, 2018 at 11:54 AM Peter C. Wallace <[email protected]> wrote:
> On Thu, 29 Nov 2018, Chris Albertson wrote: > > > Date: Thu, 29 Nov 2018 11:47:23 -0800 > > From: Chris Albertson <[email protected]> > > Reply-To: "Enhanced Machine Controller (EMC)" > > <[email protected]> > > To: "Enhanced Machine Controller (EMC)" <[email protected] > > > > Subject: Re: [Emc-users] Spindle Encoder AEDR-8300 Encoder Ring > > > > The effective pulse width is always zero if you look at the leading edge. > > Pulse length does not matter. > > > > If you care about being the same in each direction then look at the > leading > > edge when going in the normal direction and if running in reverse look at > > the trailing edge of the index pulse. > > > > The quadrature sensor will tell you the direction. Look at the last data > > from the A/B channel to determine direction then decide what index edge > to > > use. > > > > The worst case is when a person turns the spindle by hand with the motor > > powered off and moves the spindle back and forth many times triggering > the > > index from both directions. The above should track this well. But in > > real life, you never see this worst case. But still, it can be handled > > with just a few lines of code. > > > > Doesn't need any lines of code, its easily doable in hal, but as I said > there > is no application with normal LinuxCNC spindle sync-ed operations. > "Hal" is not code? It is a text file that contains instructons. Also, the reason MK is not finding wider application in machine control is because every little decision is made by asking "is this needed on a milling machine?" so after some years of this MK is very spacialized to the needs of machine tools. Maybe that is good? > > > > > > > On Thu, Nov 29, 2018 at 11:13 AM Peter C. Wallace <[email protected]> > wrote: > > > >> On Thu, 29 Nov 2018, David Berndt wrote: > >> > >>> Date: Thu, 29 Nov 2018 12:13:25 -0500 > >>> From: David Berndt <[email protected]> > >>> Reply-To: "Enhanced Machine Controller (EMC)" > >>> <[email protected]> > >>> To: [email protected], Peter Blodow <[email protected]> > >>> Subject: Re: [Emc-users] Spindle Encoder AEDR-8300 Encoder Ring > >>> > >>> Ok, thanks guys. I'll go with a seperate encoder to pickup a once per > >>> rotation count. Are there any requirements about on/off span in > relation > >> to > >>> A/B. The "centering" of the index pulse sounds like it could be a bit > >>> fiddly, and getting the pulse perfect would probably be difficult as > >> well, > >>> presumably linuxcnc won't be comparing A/B to index for any reason, > just > >>> needs that index pulse (+A/B count scaled at 1RPS). > >> > >> Mesa encoder hardware has the option of gateing index with the > quadrature > >> state but thsi is currently unused > >> > >> The only disadvantage I see from a wider index pulse is that the index > >> location would differ in different spindle directions. I dont think > there > >> is > >> any circumstance in normal LinuxCNC machining operations where this > makes > >> any > >> difference at all. > >> > >> Peter Wallace > >> Mesa Electronics > >> > >> > >> _______________________________________________ > >> Emc-users mailing list > >> [email protected] > >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > > > > > > -- > > > > Chris Albertson > > Redondo Beach, California > > > > _______________________________________________ > > 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 > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
