The following cable wiring supports most serial terminals or printers with either software or hardware handshaking. This cable is valid with any Digi DB-25 serial port.
Most terminals and printers use Data Terminal Ready (DTR) for Ready/Busy hardware handshaking. The following cable wiring supports this method.
| DB-25 (Digi End) |
DB-25 Male (Terminal/Printer) |
|||
|---|---|---|---|---|
| Signal | Pin | Pin | Signal | |
RTS |
4 |
connected to | 5 |
CTS |
GND |
Shell |
connected to | Shell |
GND |
TxD |
2 |
connected to | 3 |
RxD |
RxD |
3 |
connected to | 2 |
TxD |
SG |
7 |
connected to | 7 |
SG |
CTS |
5 |
connected to | 20 |
DTR* |
DTR |
20 |
connected to | 8 and 6 |
DCD and DSR** |
DCD and DSR |
8 and 6 |
connected to | 4 |
RTS |
* 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 printer manufacturers may use different methods of flow control. Consult your printer's documentation for specific wiring requirements.