10-pin RJ-45 plugs may be difficult to obtain in the retail market; therefore, most Digi device driver software incorporates an optional feature called ALTPIN, which swaps the logical functions of DSR (Data Set Ready) with DCD (Data Carrier Detect).
When ALTPIN is enabled, DCD becomes available on pin 1 of an 8-pin RJ-45 connector (equivalent to pin 2 of a 10-pin connector).
| Signal | Description | DTE Use | Pin # |
|---|---|---|---|
| RI | Ring Indicator | Input | 1 |
| DSR (DCD*) | Data Set Ready (Data Carrier Detect*) | Input | 2 |
| RTS | Request to Send | Output | 3 |
| GND | Chassis Ground | N/A | 4 |
| TxD | Transmitted Data | Output | 5 |
| RxD | Received Data | Input | 6 |
| SG | Signal Ground | reference | 7 |
| CTS | Clear to Send | Input | 8 |
| DTR | Data Terminal Ready | Output | 9 |
| DCD (DSR*) | Data Carrier Detect (Data Set Ready*) | Input | 10 |
|
*When ALTPIN is in effect. |