> > > > As far as LinuxCNC goes, to me it appears the parallel port code given the > > steplen calculations there isn't a way to bring the step > pulse low again during the same BASE_PERIOD interval which in the HAL file > example is 24uS not 10uS. Therefore I interpret the > step pulses to be twice the BASE_PERIOD time. > > > > double step on this page may do that > <http://linuxcnc.org/docs/2.8/html/hal/parallel-port.html > <http://linuxcnc.org/docs/2.8/html/hal/parallel-port.html>>
Nope. From the doc. "What is the maximum step rate? Remember, two periods to make a step. You settled on 16uS for the period, so a step takes 32uS. That works out to a not bad 31,250 steps per second." But then it goes on to show that the real restriction in their example was the dir hold setup time and by changing those parameters the step rate can be increased. The clue in that bit of text is the step len and step hold times are not nanoseconds but BASE_PERIOD events. So my original thoughts are still correct. The BASE_PERIOD is chosen to create the fastest possible step rate within reason taking into account latency. Now the source code makes more sense. Was a bit confusing thinking the steplen was nanoseconds. Thanks John _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
