No readable Data over EBus

i´m trying to get started with my Esera USB EBus coupler, but i have very much trouble.

When i connect a serial Terminal i get only that unreadable signs (See picture).
Also when i use the scre to adjut it don´t change (only when there is no more signal scre in extrem positions)

Is there anything wron ewith my Vailant heating unit?

Esera USB EBus Coupler
Putty 2400 8n1
Heating Unit Vailant