> On 29 Apr 2020, at 12:34 pm, John Dammeyer <jo...@autoartisans.com> wrote:
> 
> 
> 
>> -----Original Message-----
>> From: Peter C. Wallace [mailto:p...@mesanet.com]
>>>> 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."
> 
> 
>>> 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.
>>> 
>> 
>> The steplen _is_ specified in nanoseconds, and you can generate 1 step per 
>> base
>> thread invocation by using the double step mode (reset mode)
>> 
>> This is described in the hal_parport manual
>> 
>> 
> I couldn't find that reset mode in the hal_parport.  At least not how you 
> could have a step that lasted 5uS when the base period was 35uS.  How's that 
> timing calculated?

setp parport.0.reset-time 5000
 In the doc I linked earlier
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users

Reply via email to