LinuxCNC S-Curve Accelerations

Aciera wrote:

Sounds all sensible to me but I really don't feel competent to comment on the proposed path.
I certainly like the structured approach of your initiative, that is something that has been sorely lacking in other attempts.
I think/hope that Rob will be able to give an educated opinion on it and shape it into a concrete roadmap.

Note that Mitsubishi SSCNET requires a servo cycle <= 222us
forum.linuxcnc.org/9-installing-linuxcnc...cnet?start=70#256576
 

defenetly is great to have something faster then 1ms .. ethercat can run at 50us with 16axis but this complex calculations are far slower for now 

I think 250us is very pretty goal (common industrial standard) at any hardware and then reduce it based at used hardware 

endian wrote:

Aciera wrote:

Sounds all sensible to me but I really don't feel competent to comment on the proposed path.
I certainly like the structured approach of your initiative, that is something that has been sorely lacking in other attempts.
I think/hope that Rob will be able to give an educated opinion on it and shape it into a concrete roadmap.

Note that Mitsubishi SSCNET requires a servo cycle <= 222us
forum.linuxcnc.org/9-installing-linuxcnc...cnet?start=70#256576
 
defenetly is great to have something faster then 1ms .. ethercat can run at 50us with 16axis but this complex calculations are far slower for now 

I think 250us is very pretty goal (common industrial standard) at any hardware and then reduce it based at used hardware 

Note than many ethercat drives are also limited to 1khz in position mode. lichuan is, stepperonline/jss i think is and Im pretty sure the delta b3 is. My omrons I think are restricted to 2khz in csp mode.

For 4khz or 8khz usually you are restricted to other modes. At least in the drives I have. There definitely are (much) faster ones, but they are more specialised gear vs generic milling cnc applications.

Point being, 250us sounds great, but I don't know it needs to be any sort of priority cause only few people could use it. But then maybe those few people are important (like the people I know wanting to nanometer scale optical things and MUST have the higher "loop" speed so can't entertain linuxcnc right now)