Converting an RJ50 Serial Connector to DB9 or DB25

Updated Nov 10, 2023

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. NI 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-