Biostar BI94GS-IAB Setup Manual page 13

JCOM1 & JCOM2: Rear Serial Port Connectors
The motherboard has 2 Rear Serial Port Connectors for connecting Serial Port.
JSEL2: RS-232/422/485 Switch Headers for JCOM1A
The header determines that JCOM1A belongs to RS-232, 422, or 485.
(Default: RS-232)
COM 2
Pin RS232
1 -PDCD
2 PSIN
3 PSOU T
COM1
4 -PDTR
5 GND
6 -PDSR
7 -PRTS
8 -PCTS
9 -PRI
10 NC
RS-232
1-3
2-4
7-9
8-10
BI94GS-IAB
RS422 RS485
TX- TX-
TX TX
RX NC
RX- NC
GND GND
NC NC
NC NC
NC NC
NC NC
NC NC
RS-422 RS-485
3-5 3-5
4-6 4-6
9-11 9-11
10-12 10-12
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