Listing 4: Event-handler code that changes the function generator IVI-COM object.

private void trackBar1_Scroll(object sender, System.EventArgs e)
{
    int returnCount;
    // Populate the programMessage byte array from a String
    programMessage = Encoding.ASCII.GetBytes("FREQ " 
                     + trackBar1.Value.ToString() 
                     + " Hz\n");
    visa32.viWrite(VisaHandle,
       programMessage,
       programMessage.Length,
       out returnCount); 
}