Campbell Scientific MD485 RS-485 Multidrop Interface - Manual (Page 66)

Appendix H. MD485 Port Pin Descriptions
H-2
RS-232 CONNECTOR, 9-PIN D-SUB FEMALE
PIN I/O FUNCTION
1 +5V DCD
2 O RXD
3 I TXD
4 NC DTR
5 GND GND
6 +5V DSR
7 NC
RTS
8 O CTS
9 NC RI
I = Signal Into the MD485, O = Signal Out of the MD485, NC = No
Connection
RS-485 Port
RS-485 CONNECTOR, 3-PIN TERMINAL BLOCK
PIN I/O FUNCTION
1 GND Signal Ground
2 I/O 485_IO- (A)
3 I/O 485_IO+ (B)
I = Signal Into the MD485, O = Signal Out of the MD485