Hi David, The error is correct, there is no API for putting a logical value in a netCDF attribute (or a variable either). The twelve netCDF primitive types do not include logical: http://www.unidata.ucar.edu/software/netcdf/docs/netcdf.html#External-Types --Russ Russ Rew UCAR Unidata Program address@hidden http://www.unidata.ucar.edu Ticket Details =================== Ticket ID: XDD-271000 Department: Support netCDF Priority: Normal Status: Closed