This document describes the X.21 cable assembly and pinouts (Data Communications - DCE). Cisco Part#: CAB-X21FC=
| 60 Pin1 | Signal | Description | Direction | 15 Pin | Signal |
|---|---|---|---|---|---|
| J1-48 J1-47 |
GND MODE_2 |
Shorting group | - | - | - |
| J1-46 | Shield_GND | Single | - | J2-1 | Shield GND |
| J1-28 J1-27 |
RxD/TxD+ RxD/TxD- |
Twisted pair no. 6 | J2-2 J2-9 |
Transmit+ Transmit- |
|
| J1-1 J1-2 |
CTS/RTS+ CTS/RTS- |
Twisted pair no. 1 | J2-3 J2-10 |
Control+ Control- |
|
| J1-11 J1-12 |
TxD/RxD+ TxD/RxD- |
Twisted pair no. 3 | J2-4 J2-11 |
Receive+ Receive- |
|
| J1-9 J1-10 |
RTS/CTS+ RTS/CTS- |
Twisted pair no. 2 | J2-5 J2-12 |
Indication+ Indication- |
|
| J1-24 J1-23 |
TxC/RxC+ TxC/RxC- |
Twisted pair no. 4 | J2-6 J2-13 |
Timing+ Timing- |
|
| J1-15 Shield |
Control_GND - |
Twisted pair no. 5 | - - |
J2-8 Shield |
Control GND - |
Arrows indicate signal direction:
indicates DTE to DCE, and
indicates DCE to DTE.
1 Any pin not referenced is not connected.

