I suppose the commands are the same or similar for SestoSenso2 and Esatto 2. Look at the sestosenso2 driver source (sestosenso2.cpp, sestosenso2.h), I implemented commands in seperate class 'CommandSet' with Esatto driver in mind. You can use it and 'SestoSenso2' class as well.
If you test communication in terminal, first you have to setup some flags, disable ECHO and enable ICANON by stty command in linux (as I remember) to get the correct single line response.