Trying to optimize base period, etc.

Also, does the max speed override the program g-code speed settings? My son is the g-code cnc expert, not me. I'm guessing the speed is too fast causing the following errors.

It seems to work if (1) Microsteps are just 2, or (2) Microsteps are (4) AND speeds is 30in/min (.5/s). Is that pretty much my limits or is there something else that I should be tweaking? Accel is 5in/s^2 (don't really know what's realistic). With the 2ustep config I get a base period of 100,000ns. Not sure if this is large, small or average. Just trying to understand real-world configs. Thanks.

Have you read this?
linuxcnc.org/docs/2.5/html/motion/tweaking_steppers.html

does the max speed override the program g-code speed settings?

Yes.

Rick G

nerdsite wrote: I thought 5100ns was pretty good jitter (just according to what I read on this site).

Sorry, my mistake. Yes, 5100 nS is excellent. I was out by a factor of 10.

So, with a 5100nS latency but realtime delays on a 60,000nS base thread, something funny is going on. Maybe an infrequent issue that didn't happen during the latency test?

Have you tried running the latency-histogram?

Yes; however, that doesn't mean I understand it all fully. It seems if I put microsteps, then the calcs change. Do I then need to adjust the step lengths or something for microsteps? If I kicked down the % speed it seemed to not get the following errors @ 4 usteps. However, all seemed to run fine @ 2 microsteps.

nerdsite wrote: Yes; however, that doesn't mean I understand it all fully. It seems if I put microsteps, then the calcs change.

Yes, because at 4 micro-steps it takes 4 x as many steps per second to move at the same speed as it does at full-stepping.

The motor is probably 200 steps per rev. A 4x microstepping it is 800 steps per rev, at 16 microsteps it would be 3200 steps per rev.