The switch is a 8 Gigabit L2 switch with 4-Port PoE+.
Power is supplied via a 53.5V 1.31A barrel connector.
The UART is broken out to unpopulated header J2
The footprints R27 (0201) and R28 (0402) are not populated. To enable serial console, 50 ohm resistors should be soldered – any value from 0 ohm to 50 ohm will work. R27 can be replaced by a solder bridge.