where can i find ADS output data array?

In Agilent Advanced Design System, I found some tutorial about PhaseNoise using PhaseNoiseMod, and to its output, named wire as VCO_OL, but at some equations, it use VCO_OLout=VCO_OL[1], is this VCO_OL[1] a member of result data array? and what's the other member of this data array stands for? Where could I find the defination about this, I look for the help button but it only explain the input parameters, nothing about output.
Anyone who knows something about this please help me, thank you very much~~~