### RJ-45 10-Pin to Modem

The simplest way to connect a modem to an adapter with RJ-45 connectors is to use Digi RJ-45 to DB-25 Cable Adapters. These adapters use 10-pin RJ-45 plugs, and therefore provide full modem support (Ring Indicator and Data Carrier Detect are only available on 10-pin RJ-45 connectors).

RJ-45 to DB-25 Modem Cable (10 Wire)

RJ-45 (Digi End) |  | DB-25 Male (Modem End)
--- | --- | ---
Signal | Pin | Pin | Signal
RI | 1 | connected to | 22 | RI
DSR | 2 | connected to | 8 | DSR
RTS | 3 | connected to | 4 | RTS
GND | 4 | connected (via shield) to | 1 (or shell) | GND
TxD | 5 | connected to | 3 | RxD
RxD | 6 | connected to | 2 | TxD
SG | 7 | connected to | 7 | SG
CTS | 8 | connected to | 5 | CTS
DTR | 9 | connected to | 20 | DTR
DCD | 10 | connected to | 6 | DCD

Follow this chart when building your own modem cable.

Copyright © 1999, Digi International. All rights reserved.