
The RS-232 interface is used for both programming the DRO-550 and for interfacing it to a PC. The cable is wired as indicated in the table. The connector is a 9 pin female d-sub connector.
| RS-232 Signal |
PCB Pin (J18) |
Female DB-9 Pin |
| Tx | 1 | 3 |
| Rx | 2 | 2 |
| Ground | 3 | 5 |