[grounding] Grounding (PE / GND) of a system containing many OEM electronics

[m k]

Have you been around so long that old ISA was the first analog card bus?
If so then much have changed since then.

Mini-PC is one of the newer things.
Some have an add-on card slot, but it's probably pretty short.

How much data is needed?
Unshielded 100M Ethernet would isolate, standard allows a distance up to 100m.

Industry seems to try it so that higher frequencies are in a single cage.
Cabinet walls are also pretty thick.

[uer166]

@uer166: "tying all the secondary grounds of the various boards together where the SE analog signals live with a low impedance" -> That we have never considered but I remember seeing something similar being mentioned in EN 60204-1:


Is that similar to what you mentioned?

Yeah this is exactly what I meant. Though the image shows a cable, I meant more generally wide/low impedance ties that can be a cable, a big flat grounding braid, chassis, etc. IMO the issue is not "screen current" that it solves, but rather reducing the voltage drop between the boards' ground references to which your "accurate single ended" signals are referenced to.

[Limhes]

Thanks for the clarification! This goes on the list of strategies to be tested.

Thanks all once again, very much appreciate the input.