| Signal | Description | DTE Use | Pin # |
|---|---|---|---|
| GND | Chassis Ground | N/A | Shell |
| TxD | Transmitted Data | Output | 2 |
| RxD | Received Data | Input | 3 |
| RTS | Request to Send | Output | 4 |
| CTS | Clear to Send | Input | 5 |
| DSR | Data Set Ready | Input | 6 |
| SG | Signal Ground | reference | 7 |
| DCD | Data Carrier Detect | Input | 8 |
| DTR | Data Terminal Ready | Output | 20 |
| RI | Ring Indicator | Input | 22 |