On Sunday 23 October 2016 16:25:46 Danny Miller wrote: > I use the Mesa 7i92. It is EXCELLENT. I prefer it over PCI solutions > just because I can keep the controller separate from the PC without a > lot of wiring. > So, all I have to is find one.
> It works fine with my 1ms servo-thread. I have no reason to see if it > goes further. It offloads all the pulse generation for the steppers > so it doesn't require a lot of the computer. The recommended setup > uses a PLL which compensates for jitter down the ethernet link, it's > probably overkill but it's just a HAL component to add. > > I don't know what other issue I'd run into with latency in a stepper > system. I had no problem at all. I don't know how it'd go with servo > encoders. I've encoder feedback to the spindle on 2 of my machines now. It can be a cast iron kitty to make it work, encoder jitters drive the PID out of its skull at times. I can only use about .5% of the Pgain the steppers use. And thats after I rigged up some hal trickery to average the timeing of the last 4 encoder edges going by which divides the velocity noise by a /4 factor. I don't think that lag in the turnaround for a rigid tap is helped by that as I seem to be getting looser taps than normal since I put that code in. > I discovered it does NOT work with all ethernet ports, my MB had a > very odd onboard ethernet chipset and LinuxCNC didn't start at all. > Adding a PCI ethernet card was an easy answer for me, but not for > someone with that SBC with no PCI, but I doubt that will come up. > > It does require you to dedicate that ethernet port. No routers. Since > that SBC has only one ethernet port, your network access would have to > be through USB. Thats a potential full stop. But on a board with two ports, one could be dedicated to lcnc, while the other was checking for updates. If no routers, how about switches/hubs and an eth0:1 setup? Sharing that port IOW. > No biggie, on my CNC (not an SBC) I just added a wifi USB already. > > Mesa 7i92 are totally available from the mfg: > > http://store.mesanet.com/index.php?route=product/product&product_id=30 >2 Not according to that web page 2 hours ago. Out of stock. But this link say 170 on the shelf? Left hand, please call right hand. :) Either that or the boat finally docked, I understand they've got labor problems at some west side ports. > There are 3 versions which change the port on the end: male DB25, > female DB25, male 26-pin DIL header. But the one in the middle is > always a male DIL26 header. And the 7i92M means its a male db25 on the end? > Danny > > On 10/23/2016 2:07 PM, Gene Heskett wrote: > > On Sunday 23 October 2016 13:54:59 Dave Cole wrote: > >> Connect to a Mesa ethernet controller? > >> > >> Dave > > > > What about the latency? Can it match the 1 to 4 kilohertz > > servo-thread loop I have used? > > > > It's no help that the 7i92 is out of stock on both Peters and Johns > > web pages. How long to source one of those critters? > > > > Or that what I think would be the next step up, as in skipping the > > db25 breakouts in favor of direct i/o is the 7i76E @ $200. > > > > So I guess I am stuck, drooling over the possibilities, but still > > using an old Dell I paid $75 for, with a single core P4 that burns > > 90 watts, and a 5i25, in a box that occupy's at least a cubic foot > > to run this lathe. There IS a limit to the relatively clean space > > under the drawers in this Sheldon cabinet, so the motor driver box I > > am building up from an old rusty box will have to live out where > > swarf will collect on top of it. > > > > I do like the ethernetted idea because theres little effect to > > moving the computer to a cleaner location, a most desirable > > condition. Sigh. And not helped that my giddyup got up and left me > > needing another nap this morning. But I think I can go cobble up > > some hole locations and get this stuff mounted yet today. > > > >> On 10/23/2016 1:46 PM, Gene Heskett wrote: > >>> On Sunday 23 October 2016 12:02:58 Roland Jollivet wrote: > >>>> By the way, while you guys are discussing SBC's, there's also the > >>>> UP board <http://www.up-board.org/> too, which is x86. > >>>> > >>>> Here's a fun video <https://www.youtube.com/watch?v=dPJiShBIPw8> > >>>> on it too. Worth looking at... > >>> > >>> Nice board, pricy tho at a 90 buck starting point. And no pci > >>> buss, so nothing from pico or mesa is usable. Whats available to > >>> plug onto the 40 pin pi header that can duplicate a mesa anything > >>> i/o functionality? > >>> > >>> C'mon crickets, speak up. I looked thru that blog post link to > >>> see what might be found only to see that decently capable boards > >>> for the BBB like the k9 have been discontinued for lack of > >>> interest. > >>> > >>> This is not how we move linuxcnc to the next generation hardware. > >>> > >>> Cheers, Gene Heskett > >> > >> ------------------------------------------------------------------- > >>--- -------- Check out the vibrant tech community on one of the > >> world's most engaging tech sites, SlashDot.org! > >> http://sdm.link/slashdot > >> _______________________________________________ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > > Cheers, Gene Heskett > > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, SlashDot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > 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> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
