Table 5–1 Serial port configurations
COM
Port
Address IRQ
Interface BIOS
Setup
for COM2
Connector
COM1 3F8h*,
2F8h,
3E8h, 2E8h
IRQ4*,
IRQ3
RS–232 – 8 wire
NA
J15
COM2 3F8h,
2F8h*,
3E8h, 2E8h
IRQ4,
IRQ3*
RS–232 – 8 wire
RS232 J15
COM2 3F8h,
2F8h*,
3E8h, 2E8h
IRQ4,
IRQ3*
RS–422 – 4 wire
RS–485 – 2 wire
RS422/485 J7
* = default
Table 5–2 COM1 and COM2 connector pin-outs (J15 connector)
COM1 COM2
Pin# RS–232
signal
Pin# RS–232
signal
1
2
3
4
5
6
7
8
9
10
DCD
DSR
RxD
RTS
TxD
CTS
DTR
RI
GND
nc
11
12
13
14
15
16
17
18
19
20
DCD
DSR
RxD
RTS
TxD
CTS
DTR
RI
GND
nc
Table 5–3 J7 – COM2 connector pin-outs and pin-outs for 1.25 mm RS–422/485 cable
J7 connector
DB–9 connector
Pin# Signal Pin
# Pin#
1 TXD+
1
2 TXD–
6
nc 2
nc 7
nc 3
nc 8
4 RXD+
4
5 RXD–
9
3 GND
5
45