serial interface cable DCE-DTE Serial Cable Between Cisco Routers (X.21 Format)
60 pin Cisco DB connector
to the Serial Port on Cisco Router
60 pin Cisco DB connector
to the Serial Port on Cisco Router
| Serial Port on Cisco Router Pin Name | Serial Port on Cisco Router Pin Number | Direction | Serial Port on Cisco Router Pin Number | Serial Port on Cisco Router Pin Name | Description |
|---|---|---|---|---|---|
| Ground | 46 | ↔ | 46 | Ground | Shield Ground |
| TXD/RXD+ | 11 | → | 28 | RXD/TXD+ | Twisted Pair No.3 |
| TXD/RXD- | 12 | → | 27 | RXD/TXD- | Twisted Pair No.3 |
| RTS/CTS+ | 9 | → | 1 | CTS/RTS+ | Twisted Pair No.2 |
| RTS/CTS- | 10 | → | 2 | CTS/RTS- | Twisted Pair No.2 |
| RXD/TXD+ | 28 | ← | 11 | TXD/RXD+ | Twisted Pair No.4 |
| RXD/TXD- | 27 | ← | 12 | TXD/RXD- | Twisted Pair No.4 |
| CTS/RTS+ | 1 | ← | 9 | RTS/CTS+ | Twisted Pair No.1 |
| CTS/RTS- | 2 | ← | 10 | RTS/CTS- | Twisted Pair No.1 |
| RXC/TXCE+ | 26 | ← | 24 | TXC/RXC+ | Twisted Pair No.5 |
| RXC/TXCE- | 25 | ← | 23 | TXC/RXC- | Twisted Pair No.5 |
| Ground | 15 | ↔ | 15 | Ground | Circuit Ground |
| To Local 47 | 48 | 48 | To Local 47 | Ground Mode 2 | |
| To Local 48 | 47 | 47 | To Local 48 | Ground Mode 2 | |
| To Local 52 | 51 | Ground Mode DCE | |||
| To Local 51 | 52 | Ground Mode DCE | |||
| Not Used | 16 | 16 | Not Used | Not Used |
Notes
- This was deduced from two X.21 cables hooked back to back.
- For DCE side I had to add 2 extra wires (Pins 25,26) not used in X.21, and swapped most pin pairs. I currently use this cable between a Cisco 2520 and a Cisco 1601 at 1.5 Mb/sec.