The metadata provided by Medusa (Labview channels in former times) are now labelled correctly in Go4. 
Most important data are "Cobra Set WL", "WS7 Meas WL", "PTB U scal", "Ohmlabs U scal", which correspond to the set wavelength, measured wavelength, voltage measured at the PTB divider, and voltage measured at the Ohmlabs divider.
Other channels are mostly for debugging purposes.