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20
Chapter 2 Hardware Installation
Chapter 2
COM (Serial) Ports
COM 1 and COM 2 can be selected among RS232, RS422 and RS485 in the BIOS (the “SIO
NUVOTON6106D” submenu of the Advanced menu).
COM 3 and COM 4 are fixed at RS232.
The serial ports are asynchronous communication ports with 16C550A-compatible UARTs that
can be used with modems, serial printers, remote display terminals, and other serial devices.
Connecting External Serial Ports
Your COM port may come mounted on a card-edge bracket. Install the card-edge bracket to
an available slot at the rear of the system chassis then insert the serial port cable to the COM
connector. Make sure the colored stripe on the ribbon cable is aligned with pin 1 of the COM
connector.
BIOS Setting
Configure the COM ports 1/2/3/4 in the Advanced menu (“SIO NUVOTON6116D” submenu) of
the BIOS. Refer to the chapter 3 for more information.
COM 3/4: RS232
DCD-
RXD
TXD
DT
R-
GND
RT
S-
RI
-
DSR
-
CTS-
1
2
9
10
COM 1/2: RS232/422/485
Please refer pin definitions
at right.
1
2
9
10
I/O Connectors
Pin
RS232
RS422 Full Duplex
RS485
1
DCD-
TX-
DATA-
2
RD
TX+
DATA+
3
TD
RX+
N.C.
4
DTR-
RX-
N.C.
5
GND
GND
GND
6
DSR-
N.C.
N.C.
7
RTS-
N.C.
N.C.
8
CTS-
N.C.
N.C.
9
RI-
N.C.
N.C.
COM 4
COM 2
COM 3
COM 1
COM 1/COM 2
