Here is a couple crap explanations... Printer port https://www.youtube.com/watch?v=f7dI0JYC5q4&t=
mesa https://www.youtube.com/watch?v=btYsWPriZVU&t= On Sun, Jun 23, 2019 at 5:06 PM andy pugh <bodge...@gmail.com> wrote: > On Sun, 23 Jun 2019 at 22:47, Peter C. Wallace <p...@mesanet.com> wrote: > > > > > So that begs the question. Am I the first to try using a 7i92H to > replace two > > > parallel ports for LinuxCNC? If it has been done is there not a simple > > > template for even just one of the DB-25 with simple step/dir, limit, > estop, > > > machine enable? > > > > No, but it does require some hal knowledge and understanding that the > card is > > electrically compatible with parallel port breakouts but the hal file > setup is > > compleley different due to the fact that the fast I/O is done in hardware > > > In theory you could use the software stepgen and drive the Mesa GPIO > in the base thread (that functionality is available in the driver) but > at that point you might as well use an actual parallel port. > > The way to think about this is to draw a box around the Mesa card that > moves the stepgen, pwmgen, encoder counters etc into the Mesa card, so > the HAL connections that used to go to the stepgen now go to the Mesa > card. > > In general the pin names are just the same, but prefixed by the board name. > > So: > > net Xpos cmd <= joint.0.motor-pos-cmd > net Xpos-cmd => stepgen.0.position-cmd > > becomes > > net Xpos cmd <= joint.0.motor-pos-cmd > net Xpos-cmd => hm2_7i92.0.stepgen.00.position-cmd > > And then the link from the stepgen to the physical pins is determined > by the FPGA firmware. > > The downside is that you have to find a firmware to suit the hardware > pinout. > The upside is MHz step rates. > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > — George Fitch, Atlanta Constitution Newspaper, 1916 > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
