private void button3_Click(object sender, EventArgs e) { AD9958 selectedDDS = ddsList[deviceListBox.SelectedIndex]; List <double> freqs = new List <double>(); double start = 10e6; double incr = 1e6; for (int k = 0; k < 20; k++) { freqs.Add(start + k * incr); } selectedDDS.SetFrequencyList(freqs.ToArray()); }