Com1 connector (cn3), Com2 connector (cn4), System power switch (cn5) – Axiomtek PICO841 User Manual
Page 35: 3 com1 connector (cn3), 4 com2 connector (cn4), 5 system power switch (cn5)

PICO841 Intel
®
Atom
TM
Processor E3845/E3827 Pico-ITX Board
AX93283 I/O Board
29
CN3
CN4
3.5.3
COM1 Connector (CN3)
CN3 is the lower connector of the double-deck DB-9 connector. Only COM1 comes with
power capability on DCD and RI pins by setting jumpers (see section 3.4.1). The pin
assignments of RS-232/422/485 are listed in table below. If you need COM1 port to
support RS-422 or RS-485, please refer to section 6.4.
3.5.4
COM2 Connector (CN4)
CN4 is the upper connector of the double-deck DB-9 connector. The pin assignments of
RS-232/422/485 are listed in table below. If you need COM2 port to support RS-422 or
RS-485, please refer to section 6.4.
3.5.5
System Power Switch (CN5)
This switch is for turning on/off the system power.
Pin RS-232
RS-422
RS-485
10
DCD
TX-
Data-
11
RXD
TX+
Data+
12
TXD
RX+
N.C
13
DTR
RX-
N.C.
14
GND
No use
No use
15
DSR
No use
No use
16
RTS
No use
No use
17
CTS
No use
No use
18
RI
No use
No use
Pin RS-232
RS-422
RS-485
1
DCD
TX-
Data-
2
RXD
TX+
Data+
3
TXD
RX+
N.C
4
DTR
RX-
N.C.
5
GND
No use
No use
6
DSR
No use
No use
7
RTS
No use
No use
8
CTS
No use
No use
9
RI
No use
No use
Function
Description
On
Turn on/off system
Off
Keep system status