National Instruments 3.22E+04 用户手册

Figure 2-7 and Table 2-3 give the pin locations and descriptions of the 
DB-25 connector, which is on the optional 10-position modular jack 
to DB-25 cable.

Figure 2-7.  DB-25 Connector Pin Locations

Table 2-3.  DB-25 Pin Descriptions

2

TXD

RTS+ (HSO+)

3

RXD

CTS+ (HSI+)

4

RTS

RTS- (HSO-)

5

CTS

TXD+

6

DSR*

CTS– (HSI–)

7

GND

RXD–

8

DCD*

GND

20

DTR*

RXD+

22

RI*

TXD–

Pins not listed in this table are No Connect.

* These signals are not supported by the isolated 232 ports.

PIN 1

PIN 25

PIN 13

PIN 14