/// <summary>
/// Sets the waveform to waveform memory on the external source for specified channel
///
/// SOURce[n]:FUNCtion:USER
/// </summary>
/// <param name="extSource">the EXTSOURCE object</param>
/// <param name="filename">waveform filename</param>
/// <param name="channel">channel to use as source</param>
public void SetExtSrcFunctUser(IEXTSOURCE extSource, string filename, string channel)
{
extSource.SetExtSrcFunctUser(filename, channel);
}