Chapter 2
QDSP-2090 Series User’s Manual
COM port
COM port with the pin definitions.
Pin
RS-232
RS-422
Half Duplex
RS-485
Full Duplex
RS-485
1 DCD
TX- DATA- TX-
2 RXD
TX+ DATA+ TX+
3 TXD
RX+ NA RX+
4 DTR RX- NA RX-
5 GND
GND
GND
GND
6 DSR NA NA NA
7 RTS NA NA NA
8 CTS NA NA NA
9 RI
NA NA NA
Figure 6 COM port
COM