Connecting to a CNC machine, pros and cons of USB vs PP vs Ethernet etc.

[Jon.]

Both Ethernet and usb are digital so noise is likely to effect both if large enough, i have my uc300 running an inch away from my 2200w vfd and two inches from a honking great 55v toroidal transformer without issue so sounds like your noise may have been in your power supply, were you using ac filters? either that or there was something massively wrong happening in the next room.

[m_c]

Both Ethernet and usb are digital so noise is likely to effect both if large enough, i have my uc300 running an inch away from my 2200w vfd and two inches from a honking great 55v toroidal transformer without issue so sounds like your noise may have been in your power supply, were you using ac filters? either that or there was something massively wrong happening in the next room.

I suspect Jazz's source of interference was a HF Plasma Cutter, or HF TIG welder, both of which will produce and emit interference that will far exceed anything a properly wired VFD will.
If you get the chance, you might want to try firing one up next to your machine, and see if it still remains as stable, as there's nothing quite like a few hundred volt high frequency unsheilded arc to highlight the slightest deficiency in your shielding/grounding/power filtering/communications.

[Jon.]

Be interesting to find out. Though a grounded metal enclosure around the controller, which should be general practice, would most likely solve the issue. If it didnt id be suprised and very much suprised if the etherenet controller wasnt effected by such levels of noise.

[m_c]

It probably would be, however Ethernet is far better at handling and recovering from noise problems, as it can handle and resend lost data packets, whereas USB doesn't have that capability. I do suspect USB comms could be improved to handle these situation better, but it'll add cost, complexity, and processing overheads.

I know from various USS discussions, Greg struggled to fit all functionality into the USS, so I suspect it was having to do the bare minimum to handle communication. When it came to the ESS, Greg used a larger FPGA, and I do suspect there may be more going on within it to handle communication problems.

I also suspect other manufacturers have looked at the issues from the USS, and implemented strategies to better handle communication faults, as other good quality USB controllers don't seem to suffer from anywhere near as many communication faults.
You have to remember USS was the first successful USB external motion controller for Mach3, and it did achieve a lot, however I do think it's probably time to retire it, or at least update the hardware.

[JAZZCNC]

Be interesting to find out. Though a grounded metal enclosure around the controller, which should be general practice, would most likely solve the issue. If it didnt id be suprised and very much suprised if the etherenet controller wasnt effected by such levels of noise.

All the machines I build use Metal Enclosures and believe me it doesn't help much. Ethernet isn't affected nearly as much and better Motion devices like CSlabs it doesn't affect at all.
I'm just currently testing the Pokey's 57CNC which uses Ethernet and it survived the Tig test but then funnily enough it threw a little wobbly by E-stoping when I was using the Mig welder.? It's behaved since thou so could have been that and the fact i'm using the 5V signal for E-stop. (plus it's rough wired on the bench)