Asus RS120-E4/PA4 - Manual (Page 60)

Chapter 4: Motherboard information 4-12
6.. USB.port.connector.(10-1.pin.USB34)
By default this connects to the front panel to support two USB 2.0 ports.
7.. Serial.port.connector.(10-1.pin.COM2)
This connector is for a serial (COM) port. Connect the serial port module
cable to this connector, then install the module to a slot opening at the back
of the system chassis.
The serial port module is purchased separately.
P5M2-R
®
P5M2-R
Serial.port2.(COM2).connector
PIN 1
COM2
P5M2-R
®
P5M2-R.USB.2.0.connectors
USB+5V
1
USB_P3-
USB_P3+
GND
USB+5V
USB_P4-
USB _P4+
GND
NC
USB34