Matthias,
You must have missed my previous post #455608 in response to Curt's post; I mentioned in the post, "Now I know what's happening. According to the Ketron SD40 Table pdf file, your SysX is for the Audya series, and yet works on the SD40, too. I was working with the SysX messages for the MS, X, and SD series as in the manual, and none of it worked."

You can download the Audya manual. https://www.ketron.it/images/ketron/manualiPdf/E_AUDYA_SERIE_28_04_2011_SMALL.pdf.

There are a whole bunch of sysEx for many functions. Many of the sysEx messages seem to work on the SD40.

Chris