Power quality analysis

[plshelp]

Hi, I am very new to labview and now I am using NI-9225 and NI-9227 to measure current and voltage.  My connection is show as below picture. All I want is to measure the reactive power, active power, power factor and apparent power. I dont know why the value of active power and reactive power will keep changing. Only the value of apparent power if fixed and correct. Can you guys please give me some guideline to measure the active power and reactive power? Thank you.

[OneOfTheDans]

Try looking at the data coming from each Express VI (the 2 dark blue wires). You can put a Graph Indicator on your Front Panel display to see the signals. Make sure they look OK before doing further calculations.

Also, there are settings inside the Express VIs you placed for each instrument. Maybe you need to change their settings (by double-clicking the boxes).