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It took 25 years for this USB demo/explanation

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Howardlong:

--- Quote from: coppice on June 09, 2021, 09:42:28 pm ---
--- Quote from: Howardlong on June 09, 2021, 09:35:03 pm ---I'm not sure if those are rose tinted glasses, but I had very different experiences, usually resorting to BlackBox PCI serial cards, or PCMCIA cards for laptops if I wanted reliability. Back in those days, I worked on and developed autonomous and remotely managed satellite groundstation solutions: dishes, radomes, rotators etc. used across the world at latitudes of -90 to +78 degrees. It simply wasn't possible to rely on USB solutions for these due to their unreliability. It was pot luck which COM port would be assigned to which adapter at boot time, an untenable solution for remote systems.

--- End quote ---
Most USB connectors are completely unsuitable for those types of applications. The contacts corrode and become quite flaky. That's completely separate issue from the reliability of USB as a system. That's penny pinching on contact material. The erratic port assignment with Windows can be a PITA. Most of the things I've done with numerous USB serial ports has been with Linux, and the only issues I've had have been those flaky contact ones.

--- End quote ---

All USB connections would have been in an HVAC controlled environment housed at the base of the radomes together with the rest of the gear like radios, HPAs, PCs, axis controllers etc in 19" racks. The RF and control cables run up inside the radome: the only electronics not in HVAC is the receive LNAs and LNBs mounted directly at the feedpoint. Control signals are terminated with captive Amphenol multipole connectors. There's never any USB going to the antenna for a multitude of reasons, including cable length limitation, and not least RFI. It's much simpler than that at that point ;-)

We did test running 10Base2 some years ago to improve flexibility and reduce the number of control cables, but RFI was a show stopper.

The problem in this case wasn't anything to do with the reliability of USB connectors, it was to do with configuration and software reliability.

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