Is there a way to download FW on site without PC?
You may have two EEPROMs each having different FW, mounted on your board.
The EEPROMs maybe mapped to User Bootloader location of ADuCM355 Flash memory. (Note: The user bootloader is placed in the first 8 kB of user flash.)
Based on switch settings, one particular EEPROM may be enabled.
This way, FW maybe changed without PC.
For details on how to enter UserBootloader Boot mode, refer to