| LED | INDICATION | OFF | 🔴 | 🟠 | 🟢 |
|---|---|---|---|---|---|
| RTS | RTS-line status (D15 Pin 13) | Inactive | Active | – | – |
| CTS | CTS-line status (D15 Pin 6) | Inactive | Active | – | – |
| TD | TD-line status (D15 Pin 11) Radio modem is receiving data from the serial port and is sending them via UHF. | No data | Data | – | Test Tx active |
| RD | RD-line status (D15 Pin 9) Radio modem is receiving data and is sending them via serial port. | No data | Data | – | – |
| CD | Status of the radio interface. Note that the status of CD-line (D15 pin 2) may differ from the status of CD LED. | No Signal | Transmitter is ON | Noise | Reception |
