RS-232, DB25

DTE

Data Terminal Equipment (The PC)

MALE CONNECTOR

DCE

Data Carrier Equipment (The Modem)

FEMALE CONNECTOR

note:

All signal names are given with reference to the DTE

(TD, Transmit Data means the DTE is transmitting to the DCE)

PIN

DIRECTION

ABBREVIATION

NAME

DTE - DCE

1

SHIELD

2

>

TD

TRANSMIT DATA

3

<

RD

RECEIVE DATA

4

>

RTS

REQUEST TO SEND

5

<

CTS

CLEAR TO SEND

6

<

DSR

DATA SET READY

7

<>

GBD

SIGNAL GROUND

8

<

CD

DATA CARRIER DETECT

9

10

11

12

13

14

15

16

17

18

19

20

>

DTR

DATA TERMINAL EQUIPMENT READY

21

22

<

RI

RING INDICATE

23

24

25

RS-232, DB9

DTE

Data Terminal Equipment (The PC)

MALE CONNECTOR

DCE

Data Carrier Equipment (The Modem)

FEMALE CONNECTOR

note:

All signal names are given with reference to the DTE

(TD, Transmit Data means the DTE is transmitting to the DCE)

PIN

DIRECTION

ABBREVIATION

NAME

DTE - DCE

1

<

CD

DATA CARRIER DETECT

2

<

RD

RECEIVE DATA

3

>

TD

TRANSMIT DATA

4

>

DTR

DATA TERMINAL EQUIPMENT READY

5

<>

GND

SIGNAL GROUND

6

<

DSR

DATA SET READY

7

>

RTS

REQUEST TO SEND

8

<

CTS

CLEAR TO SEND

9

<

RI

RING INDICATE

Null Modem

Loop Back

Snooper

end