| Pin | Signal | Description |
| 11,17 | GND | |
| 12 | Tx | |
| 13 | Rx |
Here is an alternate pinout, tested. Colors of wires are checked from the data cable of OT835 Data PC Kit USB Connection OTD-09987. Signal level is 2.5V.
| Pin | Signal | Signal at the cable | Description |
|---|---|---|---|
| 4 | GND | GND | black |
| 10 | DTR | DSR | yellow |
| 11 | DSR | DTR | purple |
| 12 | TxD | RxD | orange |
| 13 | RxD | TxD | red |
| 14 | CTS | RTS | blue |
| 15 | RTS | CTS | green |
| 17 | frame ground |

