Converting an RJ50 Serial Connector to DB9 or DB25

Overview

This article provides the pin assignments for RJ50, DB9, and DB25 connectors, and explains how to convert from one to another.

Introduction

The table below describes how the pins map from RJ50 to DB9 and DB25. National Instruments sells cables that accomplish both of these tasks. Information on how to purchase these cables can be found in Products and Services: Cables and Accessories.

 

DB-9 Pin

DB-25 Pin

RJ-50 Pin

Signal (232)

Signal (485)

1

8

10

DCD

GND

2

3

9

RXD

CTS+

3

2

8

TXD

RTS+

4

20

7

DTR

RXD+

5

7

6

GND

RXD-

6

6

5

DSR

CTS-

7

4

4

RTS

RTS-

8

5

3

CTS

TXD+

9

22

2

RI

TXD-

 

The figures below show the pin-outs for each of these connectors.

 

RJ50 Connector (Male)

DB-9 Connector (Female)

DB-25 Connector (Female)