i have downloaded the package from address https://wiki.teltonika-networks.com/wikibase/images/2/2f/Standard_tftpd_recovery_1234.zip and done the following :
-set the ethernet interface of my computer to a fixed address : 192.168.1.254 ; subnet 255.255.255.0 ; default gateway 192.168.1.1.
-start the application tftpd32.exe
-check the dropdown boxes at the top. The first one is set to the directory of the application, in which the file fwupdate.bin currently is. The second box, server interface, shows 127.0.0.1.
-press and hold the reset button, connect the power jack to the RUT500, and watch the tftpd32.exe window. The server interface changes to 192.168.1.254 after a few seconds,
-BUT nothing else happens. No sign of a data transfer, the LED next to the RJ45 socket twinkles as usual showing data traffic, but it does not blink (goes on and off regularly). Nothing else happens. No indication of tranfer in progress, and no indication of transfer finished, though I have kept the reset button pressed for several minutes.
What did I miss?