Db9 Pin Assignment - StarTech.com ICUSB422 Instruction Manual

* NOTE:
In "422" mode, the ECHO setting is not used.
* The Echo mode is useful for detecting if there is data collision
occurring on RS-485. If the echoed data is not equal to the
transmitted data, then data collision is occurring.

DB9 Pin Assignment

DB9 Pin RS-422
1 TxD -
2 TxD +
3 RxD +
4 RxD -
5 GND
6
7
8
9
RS-485
Data +
Data -
NC
NC
GND
NC NC
NC NC
NC NC
NC NC
4