You can log simulation minimum and maximum values for MATLAB Function blocks using the Mininums, maximumx and overflows logging control in the Fixed-Point Tool. The logged minimum and maximum values are displayed in the MATLAB Function Report. For fixed-point data types, the report also displays the percent of current range. You can use the simulation minimum/maximum data to help you determine the optimal word length and fraction length of fixed-point data types for signals in your model. After modifying your model to use fixed-point data types, simulate again to verify that the data types cover the full intended operating range.