On Tuesday 18 August 2020 18:58:01 Frank Tkalcevic wrote: > An off topic question, not directly LinuxCNC related... > > How are motors on a serial bus controlled and synchronised? > > My only real control experience is with LinuxCNC with Mesa and > parallel port hardware where commands and feedback and precisely > timed. Sending commands and receiving feedback over a serial link I > would expect to cause synchronising problems, and the bandwidth would > reduce the update rate. > > How are these issues handled? I tried googling this, but didn't find > much - I wasn't sure what to search for. > By running the serial connection at many megabaud speeds. With spi, I am issueing 32 bit command words with the pi's gpio's, writing to the 7i90 at 40 megabaud, and reading the 7i90's replies at 25 megabaud. With a transmission line only an inch long, its bulletproof.
> Thanks, > Frank > > > > > > > _______________________________________________ > 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
