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
