If you have used rsim target, then you can follow the approach mentioned in the below link to add input arguments. https://www.mathworks.com/help/rtw/ug/rapid-simulations.html#brdeu57
1) Build the model with rsim.tlc as system target file
2) Collect parameters structure
>> param_struct = rsimgetrtp('myModel');
>> save myParams.mat param_struct;
3) If you wish to specify different input arguments:
>> param_struct = rsimsetrtpparam(param_struct,2);
>> param_struct.parameters{2}.values = [2 3];
>> save mymatfile.mat param_struct;
>> !myModel -p mymatfile.mat@2 -o rsim2.mat
