National Instruments 3.22E+04 用户手册

Figure 2-5 and Table 2-1 give the pin locations and descriptions of the 
DB-9 connector, which is on the two-port PCI serial board, the 10-position 
modular jack to DB-9 cable, the cable adapter for the eight-port board, and 
the DB-9 connectors to the sixteen-port breakout box.

Figure 2-5.  DB-9 Connector Pin Locations

Table 2-1.  DB-9 Pin Descriptions

1

DCD*

GND

2

RXD

CTS+ (HSI+)

3

TXD

RTS+ (HSO+)

4

DTR*

RXD+

5

GND

RXD–

6

DSR*

CTS– (HSI–)

7

RTS

RTS– (HSO–)

8

CTS

TXD+

9

RI*

TXD–

* These signals are not supported by the isolated 232 boards or ports 9-16 of the RS-232 
sixteen-port board.

PIN 1

PIN 9

PIN 5

PIN 6