10
DB9 PIN DESCRIPTION
The FASTCOM: 422/2-PCI features two RS-422/RS-485 channels, which are accessed through two DB9
connectors on the board.
The following is a pin description of the DB9 connectors:
PIN NO.
SIGNAL NAME
DIRECTION
1
SIGNAL GROUND (GND)
GROUND
2
READY TO SEND + (RTS+)
OUTPUT
3
READY TO SEND – (RTS-)
OUTPUT
4
TRANSMIT DATA + (TX+)
OUTPUT
5
TRANSMIT DATA – (TX-)
OUTPUT
6
CLEAR TO SEND – (CTS-)
INPUT
7
CLEAR TO SEND + (CTS+)
INPUT
8
RECEIVE DATA + (RX+)
INPUT
9
RECEIVE DATA – (RX-)
INPUT