Using an 8-pin RJ-45 plug, the following cable wiring supports most serial terminals or printers with either software or hardware handshaking using the Digi ALTPIN option. This cable is valid with any Digi RJ-45 serial port.
Most terminals and printers use Data Terminal Ready (DTR) for Ready/Busy hardware handshaking. The cable shown supports this method.
|
RJ-45 8-pin (Digi End) |
DB-25 Male (Terminal/Printer) |
|||
|---|---|---|---|---|
| Signal | Pin | Pin | Signal | |
| DCD* | 1 | connected to | 4 | RTS |
| RTS | 2 | connected to | 5 | CTS |
| GND | 3 | connected (via shield) to | Shell | GND |
| TxD | 4 | connected to | 3 | RxD |
| RxD | 5 | connected to | 2 | TxD |
| SG | 6 | connected to | 7 | SG |
| CTS | 7 | connected to | 20 | DTR** |
| DTR | 8 | connected to | 6 and 8 | DCD and DSR*** |
* ALTPIN must be turned on for pin 1 to be DCD. When ALTPIN is enabled, DCD becomes available on pin 1 of an 8-pin RJ-45 connector (equivalent to pin 2 of a 10-pin connector).
** Okidata Printers may use SSD (pin 11) instead.
***Some printers require DSR. If DSR is required, it should be either wired or the
printer set to ignore DSR (DSR Invalid).
Important: Other terminal or printer manufacturers may use different methods of flow control. Consult your printer documentation for specific wiring requirements.