Intel H310 Technical Manual page 26

(3) COM (9-Pin): RS232/RS422/RS485 Serial Port Header
*Notice: COM header can function as RS232/422/485 port header. In normal settings COMfunctions
as RS232 header. With compatible COM cable COM can function as RS422 or RS 485 header. User
also needs to go to BIOS to set 'Transmission Mode Select'
specialized cable to connect different pins of this port.
(4) GPIO (10-pin): GPIO Header
COM
GPIO
Pin 1
Pin NO. RS232
Pin 1 DCD
Pin 2 RXD
Pin 3 TXD
Pin 4 DTR
Pin 5 GND
Pin 6 DSR
Pin 7 RTS
Pin 8 CTS
Pin 9 RI
(refer to Page-33)
2
Pin1
21
6
*RS422 *RS485
(optional) (optional)
TX- DATA-
TX+ DATA+
RX+ NC
RX- NC
GND GND
NC NC
NC NC
NC NC
NC NC
at first, before using