Operation not allowed dataset is not in edit or insert state
It work:
procedure TRxDBCalcEdit.UpdateData(Sender: TObject);
begin
  if Assigned(FDataLink.Field) and FDataLink.Edit then
  begin
    if Self.Text<>'' then
      FDataLink.Field.AsFloat := Self.AsFloat
    else
      FDataLink.Field.Clear;
  end;
end;
			
				



