Note that there is not separate register for this connection ,it is already included in the P12x relay
2) You may try to swap the connection & check again with any 3rd party modbus toll (eg.Modbus Poll ,modscan etc..) to ensure the relay's port healthiness.
Check MiCOM P12x relay's communication parameters (data rate, parity, etc.) are in accordance with the supervision settings
3) Meanwhile,please check the RS485 port directly with laptop using ES software .
4) Please check whether you are using correct computer window version as per our Easergy studio(ES) release note.
Thanks to check this link to download the ES details https://www.se.com/uk/en/product-range/61035-easergy-studio/#overview
5) Check whether your RS485 terminal no.31&32 is getting proper resistance using multimeter
6) Check the earthing connection from rear port of Micom relay.
7) If still you have issue ,please contact our local Schneider after sales/services/CCC team with your setting,event file ,answer for the above and video of the test conducted with laptop with ES & 3rd party tool with right parameters & converter used during the test .

Released for: Schneider Electric Saudi Arabia