User`s manual

15
DB9 Male Connector Pin Assignments
PIN
RS-232
(Full-
duplex)
RS-422/485
4-wire
(Full-
duplex)
RS-485
2-wire
(Half-
duplex)
Signal
Direction
1 DCD OUT
2 RX RX- **DATA B(-) IN
3 TX TX- OUT
4 DTR IN
5 GND GND GND --
6 DSR OUT
7 RTS RX+ **DATA A(+) IN
8 CTS TX+ OUT
9 RI IN
NOTE: Bi-directional RS-485 BUS line.