Morning Tuesday! Thank God, my senior colleague pointed out to me how to do the proper CTRL+C in the terminal.
Let’s start by connecting Raspberry Pi to UCM board by typing
nc 10.0.0.55 (UCM board IP address) 1001 (UCM port number)
After it is connected, it will show a grey rectangle at the start of new line.
So if you just press CTRL+C, the connection will be terminated. Therefore, you must press CTRL+V+C for <STX> followed by the login info/your code, ended with CTRL+V+M for <CR>
So for my case, it would be CTRL+V+C LI1234 CTRL+V+M, which will appear as
and it will reply LU01.
Testing a simple command to turn output 1 ON,
CTRL+V+C O!0101 CTRL+V+M
which will turn output 1 ON. If it is left idle for some time, it will log out and user has to log in again before sending any more commands.