Inside Serpic, go to Settings → Interface → Select "CAN-USB" or "K-Line" depending on your engine year (Pre-2010 = K-Line; Post-2010 = CAN).
The most precise method, pulling specific build data for a unique unit. deutz serpic
If you were actually looking for a review of Deutz Serpic (Lubricants/Grease) , Deutz does manufacture a line of oils specifically for their air-cooled engines. In that case: Highly recommended. Using the correct "Serpic" spec oil is the only reason these engines survive the high heat of air-cooled operation. Do not run cheap generic oil in a Deutz! Inside Serpic, go to Settings → Interface →
Here is a review for that rugged piece of machinery: deutz serpic