Systematic approach to tracking down latency issue

Mike_Eitel wrote: I can not understand why some people's give for good reason good money for good mechanics, and then try to spare few dollars to use chepo parallel port solutions.

I have to agree with you on that.
Parallel port is ....... was a mighty device. I used it to copy files from one PC to another some 20 odd years ago as it was much faster than any floppy at that time. And it never fails to work.
And i have a lot of Mesa boards, a lot!
It all depends on a lot of factors.

Yes. And for light small, or low efforts machines or "just to have fun" etc. Linuxcnc parport solution is a super solution. Good for both worlds. Big THX for the developers.

PCW,

Just trying to understand this a bit better.

Related, but not the same I think.Would a 7i77 or similar outputting +/-10v be outputting a consistent voltage per base servo thread update? Or will it alter voltage depending on encoder count/rate?

I'm guessing it's the former?

Slightly related second question. So if I had a machine moving at 16.66ips(1000ipm) that hit a hard stop and had an f-error configured of anything less than 0.0166, assuming average timings of hard stop impact vs where in the servo thread we are, it'd be reasonable to say that the f-error trip wouldn't happen for 2 servo thread cycles? The first cycle would see some F-error and start accelerating the machine, and the second cycle would find that F-error has been exceeded and disable drives/power off.

Thanks to everyone who has contributed to this topic.

It wasn't clear to me when I set up my machine that the parallel port was such a potentially risky piece of hardware. It did seem like a nice free ride though

From what I understand from PCW the odd latency on 1ms might be acceptable depending on the acceleration of a machine. My machine's acceleration is more like 1/12G.

PCW, can you comment of the appropriate HAL plumbing to minimise these issues?

Time for me to buy a MESA board