This cable provides a convenience way to connect to your Raspberry Pi or BeagleBone Black serial console port. Inside the big USB plug is a Prolific's PL-2303TA compatible USB to Serial conversion chip and at the end of the 36" cable are four wire - power (red), ground (Black), RX (White) and TX (Green). The power pin provides the 5V @ 500mA direct from the USB port and the RX/TX pins are 3.3V level for interfacing with the most common 3.3V logic level chipsets.
Because of the separated pin plugs, this cable is ideal for powering and connecting up to the debug/login console on the Raspberry Pi or BeagleBone Black. Enable the SSH server in your Pi or BeagleBone Black, connect the pins as shown to power the board and establish the RX/TX link, then connect with a terminal program at 115200 baud.