Aaeon PCM-7890 User Manual page 37

The PCM-7890 COM2 serial port can be selected as RS-232,
RS-422, or RS-485 by setting J10 & J14.
J10
3 6 9 12
J14
*default
You can select the output mode of onboard audio connector
(CN14) by setting J15.
"Speaker out" is the output signal amplified by onboard amplifier
Line out
2
J15
4
6
*default
RS-232*
1 4 7 10
1 3 5
2 4 6
1
3
5
RS-422
1 4 7 10
3 6 9 12
1 3 5
2 4 6
Speaker out *
2
4
6
Chapter 2 Installation 25
RS-485
1 4 7 10
3 6 9 12
1 3 5
2 4 6
1
3
5