

hello. There is a project I want to make.
This is switching Ethernet communication.
I'm trying to make it using 'multiplexer'.
But a problem arose. There is no connection between the RJ-45 signal and the gnd of the 'multiplexer' chip.
The 'multiplexer' chip has an analog signal range of
-15VDC ~ 15VDC.
The potential (voltage, GND) between RJ-45 and the 'multiplexer' must be correct for the signal to be distributed through the 'multiplexer'. I am curious how I can make it have gnd.