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Hardware Configuration
MB991AF
User’s Manual
19
2
2.5.1
COM1 & COM2 RS-232/422/485 Ports (CN3)
1
6
5
9
1
6
5
9
COM1 & COM2 ports are jumper-less and configurable in BIOS.
Pin
Assigment
Pin
Assigment
1
DCD, Data carrier detect
6
DSR, Data set ready
2
RXD, Receive data
7
RTS, Request to send
3
TXD, Transmit data
8
CTS, Clear to send
4
DTR, Data terminal ready 9
RI, Ring indicator
5
Ground
Pin
Assignment
RS-232
RS-422
RS-485
1
DCD
TX-
DATA-
2
RX
TX+
DATA+
3
TX
RX+
NC
4
DTR
RX-
NC
5
Ground
Ground
Ground
6
DSR
NC
NC
7
RTS
NC
NC
8
CTS
NC
NC
9
RI
NC
NC