Lots of folks have connected a relay to an ethernet port to loop it back. When the relay is open, the connection goes away.
I am looking for a way to do some centralized polling of ports like that. I don’t want to have to build some kind of small ardueno board and burn an IP for each one. But I can’t think of a way around using an IP unless the device, such as a managed switch can do an snmp trap for each port. Maybe it will become a product if it doesn’t exist. Telemetry on a stick. Two terminals for a contact closure. POE powering. Pollable and trap sending. Hopefully something like this already exists?
