[idvusers] Question about NetCDF export

I'm having no problem (yet) with DATA > FORMULAS > EXPORT > EXPORT GRID/IMAGE 
TO NETCDF, when the original source data appeared to be stored as NetCDF.  
After just a few experiments with GRIB2 original sources, which failed, I need 
to know if the EXPORT function should work for any grid, regardless of original 
source, or only for original NetCDF data?  Thanks in advance for help.

Murray Brown