4 ms·
Completely optically isolated Ethernet couplers requires a power source on each side, but it can be done; the most accessible one is a set of media converters w
by AdrianB1 5y ago
Completely optically isolated Ethernet couplers requires a power source on each side, but it can be done; the most accessible one is a set of media converters with a very short optical patch cable. In this particular case to protect both the garage and generator side keeping the CAT6 cable underground you need one optical double conversion on each side and an independent, sacrificial power supply for the copper part converters. Doable, but too complicated.
- ComputerGuru 5y agoRight, that's the obvious option. I was thinking of a barebones "on the wire" approach but I'm not sure that's possible. The fastest integrated optoisolators I can find seem to all max out at 50MBd/s which simply isn't going to be enough to switch 100BASE-TX (which has a ~125MBd/s rate) without needing some sort of ethernet-aware logic (e.g. a primitive MAC controller) on either end to handle buffer overruns. 10BASE-T should be plenty possible though: it only needs a 16MHz channel and even sampling that 2x at the Nyquist rate of 32MHz is still within the capabilities of the $1 optoisolators. 10Mbps is plenty for an application like this one (and probably most industrial control purposes) but it's not exactly something anyone will publicly confess to wanting or using even if it's in order to pay two orders of magnitude less.
- AdrianB1 5y agoI don't know how the small optoisolators do when the current from a lightning strike can easily arch over several inches or a few feet. The ugly solution with a fiber patch cord on each side gives several feet of electrical insulation.