Page 24 724-746-5500 | blackbox.com Appendix B: Electrical Interfaces
RS-422 and RS- 485 four-wire (DB9 male)
Figure B-2. DB9 male connector.
Table B-2. RS-422 and
RS-485 (DB9 male
connector pinout).
Pin Number Signal
1RX+
2RX-
3TX+
4TX-
5GND
6 9
NOTE: Pins 6–9 are not connected.
RS-485 two-wire (DB9 male) Figure B-3. DB9 male connector.
Table B-2. RS-422 and
RS-485 (DB9 male
connector pinout).
Pin Number Signal
3DATA-
4DATA+
5GND
6 9
NOTE: Pins 1, 2, and 6-9 are not connected.