When installing a new firmware version, the process has two main steps. Firstly, the firmware file is downloaded on to the RAM memory and after that, the firmware is installed from RAM into the flash memory.

If for any reason the power from the controller is removed meanwhile the firmware is being installed into the flash memory, the memory will be corrupted and Ethernet communications will stop functioning. At this moment you the display (in case it has one) of the Trio Controller will show “SYS”.

This document explains how to recover from this error