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Using FetchCwPower and FetchWaveform IVI-COM power meter methods U200X

Question asked by eirp_inc on Oct 28, 2014
Hello rf testers. Im trying to setup a test routine using a U200X power meter and the step sweep on an E8257 source, Im using the settled TTL output on the source to trigger a measurement on the U2000.  Its all CW stuff. 

Trying to use C# and FetchCwPwr and FetchWaveform methods with the IVI-COM, but am getting stuck. Following an example that will get the waveform into OK, but Im screwing up the syntax. 
The basic example is to declare and array and set null, the call the get waveform method on the channel referencing the array. Something like this

//Declare array for waveform
Array myWaveform = null;
// Call method on the channel
myU2000.Channels.Items["CH1"].Measurements.FetchWaveform(ref myWaveform);
// do whatever with array. Iterate through it and ....

Now I cant figure out the difference in the methods and why this same method doesnt work with FetchCwPower.  FetchCwPower returns a double, so declare one then pass it to the methods, or even just set it equal to the method. Any help is appreciated.
Double dCWpower;
// passing it doesnt work
myU2000.Channels.Item["CH1"].Measurements.FetchCwPower(ref dCWpower);
// intellisense pukes as no Overload or params are need so tried just setting it to the function
dCWpower = myU2000.Channels.Item["CH1"].Measurements.FetchCwPower;

Any help would be appreciated!!! Tried using what little skills I have in Labview to but the isvalid params on Both methods are trouble for me. Im not sure how to handle them. Read the IVI foundation GSG guides multiple times, but the 34401 dmm examples dont use these methods. Not sure if many people are.  
Thanks for any response!!!