How to use mex files in MATLAB Function block?

Hi,

I am using ammonia-water thermodynamic properties in MATLAB using routines in C. When modelling dynamic systems in Simulink, I need to repeatedly call these property routines. I was using Matlab Interpreted Function Block till now. Lately, I read that replacing these with MATLAB Function block can speed up the simulations. But, when I call the property routines from within the MATLAB Fcn Block, I get an error. The code inside the block looks like this, with u1,u2,u3 being the different input properties.

function y = fcn(u1,u2,u3)
%#codegen
y = XNH3H2O('TPQ_H',u1,u2,u3);

The errors I get are:

1. Only MATLAB files are supported for code generation. Unsupported file extension 'mexw64' for 'D:/Work/XNH3H2O.mexw64'.Function'MATLAB Function' (#49.41.66), line 3, column 5:"XNH3H2O('TPQ_H',u1,u2,u3)"Launch diagnostic report. (coder error)

2. Error in port widths or dimensions. Output port 1 of 'Function_Test_2/MATLAB Function/u2' is a one dimensional vector with 1 elements. (block error)

3.Errors occurred during parsing of MATLAB function 'MATLAB Function'(#48) (Block error)

Answer 1

[Kaustubha Govind]

You will need to declare MEX-functions using coder.extrinsic, just like you would for other functions that are not supported for code-generation.