The Passive splitter receives DC power on the RJ45 socket, pins 4/5(+) and 7/8(-).
It routes the DC power to the 2.1mm DC plug and the data and power to the RJ45 Connector.
The Y splitter is used for those applications where one device is POE enabled and another device requires a DC jack input.
The POE-YSPLT-S accepts POE power on the RJ45 Jack and provides power on the DC connect and provides power and data on the RJ45 Plug. Useful for powering multiple devices from a single POE source.