Kevin Johnson wrote:cncdrive wrote:Or maybe the cable suffered mechanical damage or had somekind of unnoticable manufacturing error?!
It looks beautiful and undamaged. I took it with me to the shop where I bought the replacement and he tested it with some sort of box with multiple plugs -- I guess to see that the ground was working and the wires were unbroken. I think it could be some kind of manufacturing error -- it would be a good topic for an electrical engineering student's paper.
I agree with cncdrive the way to go is ethernet .... It's all I recommend.
I suspect as you've noted that they just tested the continuity.
To test a cable you really need a spectrum analyser at one end and a signal generator at the other end with an imposed load of the cable to test a member of frequencies to see the signal degradation in dB
Because the cables are short I suspect that the spectrum analyser would need to be quite sensitive.
An oscilloscope set up with two probes calibrated with a common signal for zero difference between the inputs over a wide spectrum, then apply the the input frequencies and measure the difference between the two probes, again using an imposed resistive load.
Then apply a external imposed noise signal via a calibrated signal generator and measure the impact of external imposed electrical noise
All a bit complex and lab environmentish for most places I suspect.... For a $10 cable.
Usb is fine for a mouse or keyboard but damn it gave me agro when I started out with the usb Smooth Stepper . Never again!
I avoid wireless for similar reasons (but I am running a plasma cutter and two vfd air compressors)
Also consider your mains power supply earthing arrangement, the distance from your earth source as some inductance and noise may be present or induced into the earth over long distances from the earth source
Earthing should be done as a star network topology,
But they are normally wired as a radial (daisy chain).... Not good but acceptable... Most won't have a problem.
Just don't ever wire them as a ring as that is where your ground loops come from
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