To update firmware of your DLN-series adapter execute DLN Firmware Update application.
You will see the following window:
If the connected device can not be seen from application, you may need to run device in the bootloader mode. To perform this, unplug DLN adapter from USB, close JP4 jumper on the DLN-2 or JP1 jumper on the DLN-1 and DLN-4M/S adapters. Open jumper. Plug adapter to USB.
Choose firmware version you want to install on the DLN-series adapter.
Press Upload button. After successful firmware update, you will see Firmware upload finished message.