Thank you, with this source.dll TSRreader is sending correct diseqc commands
Though, there are some points that still need improvement. Tuning and locking of high band frequencies takes about 15s! The reason is that at the 1st attempt no tone is applied -> failed to lock signal. After retuning a continuous tone is sent but with an additional delay of 3s after the diseqc command.
..just for information: The card/driver shows a memory effect. After (re)starting the source, voltage/tone are the same as from the previous tuning.