The new function introduced in firmware v5.23 is a software "WatchDog" timer that monitors device for "hung" network interface (possible when switching off inductive loads like relays, contactors, etc. without added snubber filter ACS40). If the CPU didn't receive any valid network packet within the user selectable time period ('IP Settings->Reboot if no RX frames in .. seconds') - device is rebooted. The default time is 300 seconds. A zero value disables this feature completely.
In this version is also added diagnostic information about the device's uptime (in the IP Settings menu). A bug in v5.22 is cleaned in setting the "UDP port for remote IO" to values below 1024.