Com1 Connector (Cn3); Com2 Connector (Cn4); System Power Switch (Cn5) - AXIOMTEK PICO840 User Manual

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 5.4.
Pin RS-232
10 DCD
11 RXD
12 TXD
13 DTR
14 GND
15 DSR
16 RTS
17 CTS
18 RI
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 5.4.
Pin RS-232
1 DCD
2 RXD
3 TXD
4 DTR
5 GND
6 DSR
7 RTS
8 CTS
9 RI
3.5.5

System Power Switch (CN5)

This switch is for turning on/off the system power.
Function Description
On Turn on/off system
Off Keep system status
AX93283 I/O Board
RS-422 RS-485
TX- Data-
TX+ Data+
RX+ N.C
RX- N.C.
No use No use
No use No use
No use No use
No use No use
No use No use
RS-422 RS-485
TX- Data-
TX+ Data+
RX+ N.C
RX- N.C.
No use No use
No use No use
No use No use
No use No use
No use No use
PICO840/842 Pico-ITX Board
CN3
CN4
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