Transducer selection

I am also using the Airmar B 744V thru hull transducer. When I went to the set up menu and it was "searching" for a transducer, none came up and the system would not let me enter my own information. Any ideas of what is happening here? I am NOT using a "chirp" sounder, just the B744 connected to the E66066 adapter cable directly to the e127 hybrid display.

Thank you.