> > > > Even th D-525-MW motherboard? I can latency-test for an hour or 2 on this > machine I'm building up right now, and not show any worse than 5.1 > microseconds for base thread latency, and If I run without that thread, > which I don't use anyway, and the worst case latency is 4850ns. Thats > right alongside the figures I've seen quoted for the STM-32. >
I think we might be looking at different numbers. The interrupt latancy on the uP is 12 to 17 cycles depending on the chip. Let's assume we run at 100MHz, so a cycle 10ns. so that is 120 to 170ns. But I doubt this is what the tool you are using measures. I think it measure maximum uncertainly or "jitter" of a loop period. So what it really measures is the time where the OS has interrupts disabled. If you were to run a thread on a timmer-based interrupt on the uP with no OS loaded the "jitter" would be effectily zero, Some picoseconds I'd guess. But any OS needs to disable interrupts to access shared memmory or maybe for some IO drivers. But if writing motion control on a uP you would not use software to make pulses so the jitter in the loop is not jitter in the pulses. the uP (unlike the Intel x86) has a"ton" on external, programmable hardware so you can make pulses using that hardware and have near perfect hardware generated waveforms Windows security can be "bullet proof". Someone who is very concerned about someone hacking their CNC miling machine could run their Windows 10 Machine on LAN that is firewalled or even "air gapped" from the Internet. Or they could run Windows in a VM. Or they could run Linux or MacOS. or IOS. > > > There is nothing special about Linux other than it provided a cheap > > and easy to get RT OS. > > And security. Windows may be improving, but connected directly to the > net, how long before its owned. I went from amiga to linux in 1998, and > have not been touched since. That of course includes using another linux > product, dd-wrt, between my local network, and the network at large on > the other side of my cable modem. > -- Chris Albertson Redondo Beach, California _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
