Pin | DTE | DCE | Description (DTE) |
|---|---|---|---|
1 | — | 5V | Not used |
2 | RDX
| TXD
| RXD
(receive data) input to the printer |
3 | TXD
| RXD
| TXD
(transmit data) output from the printer |
4 | DTR
| DSR
| DTR
(data terminal ready) output from the printer -- controls when the host may send data |
5 | GND
| GND
| Circuit ground |
6 | DSR
| DTR
| DSR
(data set ready) input to the printer |
7 | RTS
| CTS
| RTS
(request to send) the output from the printer -- always in the ACTIVE condition when the printer is turned on |
8 | CTS
| RTS
| CTS
(clear to send) - Not used by the printer |
9 | 5V | — | +5 V @ 0.75 A - FET Circuit current limited |
