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.
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 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. 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=302 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. 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
