On Saturday 12 September 2020 22:38:06 Peter C. Wallace wrote: > On Sat, 12 Sep 2020, John Dammeyer wrote: > > Date: Sat, 12 Sep 2020 19:13:43 -0700 > > From: John Dammeyer <jo...@autoartisans.com> > > Reply-To: "Enhanced Machine Controller (EMC)" > > <emc-users@lists.sourceforge.net> > > To: "'Enhanced Machine Controller (EMC)'" > > <emc-users@lists.sourceforge.net> Subject: Re: [Emc-users] Mini-PC > > > > Mini USB cable arrived via Amazon today so I could power the HDMI to > > VGA dongle. After that it was quick work to move cables from the PC > > and monitor to the Pi4. cid:image002.jpg@01D68936.9A816960 USB uses > > mouse, keyboard and power for the dongle. A 5V,2A wall wort for the > > Pi4. The Ethernet cable goes to the to the Mesa 7i92H down in the > > cabinet and it's powered from the system power supply. > > > > I had loaded the new LinuxCNC Pi distribution a couple of times a > > few days ago. Second time lucky and it finally worked with the > > 7i92H. I had also moved over the HAL and INI files from my PC > > version LinuxCNC. > > > > Deep breath. Switch on Master Power. Wait for it to boot and then > > click on the desktop icon for the mill. Why is it that these short > > cuts throw up that stupid dialog asking if I want to run it directly > > or in a terminal window. Why isn't there checkbox that says yes > > always? > > > > Anyway. LinuxCNC booted. I clicked on the ON button. Tried the > > spindle. Worked. Homed everything. That worked. Then suddenly it > > complains that the task with 1000000 is too slow and it will only > > tell me that once. > > > > Ran a few G-Code samples. Ethernet connection reported once that a > > read to the 7i92H had failed. Had to stop and restart LinuxCNC > > since that also took out the master relay. No reboot needed though. > > > > Ran some more G-Code. Tried the G01 G93 X1 A60 F0.707. Worked > > fine. > > > > So other than latency warnings and unreliable Ethernet > > communications it could be used to run the mill. But I wouldn't > > trust it. > > > > Now this could be a power supply or grounding issue. I think > > mounting the Pi in a proper metal box, adding a heatsink or even a > > fan and using a power supply with more than 2A capability would go a > > long way to getting rid of spurious issues. It's even possible that > > the latency issue is due to the translation to VGA from HDMI but I > > always thought that the latency issue was not a problem with > > Ethernet based Mesa boards. > > > > cid:image006.jpg@01D68936.9A816960 > > > > John Dammeyer > > Latency is less of an issue since LinuxCNC is not doing very high > speed things, but you still to run the servo thread reliably. > > The read error means that a read request timed out 5 times in a row > (default timeout is 80% of the servo thread period) > > You might try 2 ms servo thread. Others have needed that on a > RPI4
I am running a 1 ms servo-thread and a 5ms jog-thread and moved all the non time critical stuff to that slower thread. Stuff to service the twin jog dials etc is in the slower loop. I did that to make life easier on the pi3, and its worked so well I haven't undone it since putting a pi4 in a year ago. I am not using an ethernet card, but the 7i90HF rpspi driven interface. My ethernet is used for more normal stuff like keeping it updated. > > Peter Wallace > Mesa Electronics > > > _______________________________________________ > 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) 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 Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
