On Tuesday 26 March 2019 07:19:19 andy pugh wrote: > On Tue, 26 Mar 2019 at 06:35, Chris Albertson <albertson.ch...@gmail.com> wrote: > > The loops do need data. They need a target position or a target > > velocity. These targets are sent across an SPI (or I2C or Ethernet > > or,..) interface from a Linux machine. But you MUST de-couple the > > timing. Linux can not be feeding one target number at a time. > > Drawing the boundary becomes more difficult when you add in probing, > threading and spindle-synchronised motion. And it appears I may have to put a C1G rev4 back in service just for limit and home switches, the 7i76 takes too long to recognize a closed home switch.
I've not more than though of it, but have wondered if it would be possible to set up a 10 kilohertz base thread that accessed the parport, while leaving the 1 kilohertz stuff on the 7i76? I just had to slow the home_search to 120 degrees a sec to get a rotary's home switch to be recognized, otherwise it just sails on by. By putting the home/limit switches on the parport, limiting me to 5 switches which is not enough, would any response time be gained? I got the home switches I ordered yesterday, but I can readily see that they are going to have to be mounted on a springy material, seriously complicating the switch mount, otherwise they'll be smashed flatter than a coors can before the machine can get stopped. Or I use search_vels no faster than cutting vels if even that fast. This machine, with its puny motors, can still make x-y moves slightly above 200 ipm. I will probably set the homes as I intended, but it means I'll have to use very leasurely homeing moves. After switch closure, I'll have about 10 thou to get stopped before a hard smash stop. To rig more clearance means some elastomeric on the frame to cushion the button push. That will imply glue to hold it in place failures... Not what I intended when I ordered 100 of this switch for <$3. I also rxed the bigger cable chains, and got one of them installed before dinner last night, one to go. Otherwise no room left for switch wiring. 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> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
