Thanks Andy, Busy studying (again) http://linuxcnc.org/docs/2.7/html/hal/basic-hal.html John
> -----Original Message----- > From: andy pugh [mailto:bodge...@gmail.com] > Sent: March-09-19 7:55 PM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] LinuxCNC HAL contol flow > > On Sun, 10 Mar 2019 at 03:46, John Dammeyer <jo...@autoartisans.com> > wrote: > > > But I don't think LinuxCNC nor MachineKit compiles this into C code. So > how is this indirection used? > > Each component reads its inputs and computes its outputs every thread > cycle (servo or base, depending on which one it is addf-ed to) > > The HAL pins are actually pointers to locations in shared memory. > > So, a component reads the memory locations that are its inputs and > writes to the locations that are outputs. Those locations might, or > might not, be the same memory location as the input to another > component. > > There is no logic in HAL. It runs once to connect inputs to outputs. > > -- > 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
