When this VI is called a pop up window is invoked, prompting you to set the channel data. The VI checks with the generator through the VISA session which channels are available and will not execute if an error is reported in the error in (no error) cluster. The array Waveform name(s) is used to set the possible choices. Through the array Channels you can pre-load a certain selection into the window. After the pop up window has closed, the user's choice is returned through the array Channel data, which can immediately be used to replace the one in the full data cluster.