'Saturation occurred error' in lookup table while simulating my model

In my lookup table data type for first breakpoint is fixdt(0,16,0.1,0) and second fixdt(0,16,2^-9,0) and output data type is unit16. I had selected the interpolation method to "Linear" and Extrapolation method to "clip". But when i am simulating the model, i am getting an error "saturation occured name". How to fix this error?