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());
}