I have an end of an ethernet cable but I don't know where it goes. I want to see if it is connected to a device at the other end.
Looking at the pinout you have a TX+/TX- and an RX+/RX- pair of wires. From Google I have seen something about auto-negotiation and I believed this was the way to detect it, however when connected to an oscilloscope, I can't see anything.
Is there a specific way in which to detect if the cable is plugged in? (Thinking of using voltage if I could see some.) Is it possible to detect this? Well, it must be, because how do hubs/switches detect if something is plugged in?
Are there any resources which can help?
EDIT: I have tried using a scope connected directly to the pins, using DC blocking capacitors, and a transformerless differential line receiver but I havent had any change in the bogus 200V reading im getting.
Has anyone done this before? Is there a circuit which is known to work?