Simulink S-Function Output Ports

I'm having issues with a Simulink S-Function I've written, and keep getting the error message:

"Error in default port dimensions function of S-function 'LQR_Initial_System/LQR Implementation'. This function does not fully set the dimensions of output port 2"

Unfortunately, the S Function in question only has a single output port. The Simulink model explorer only recognises a single output port, as the pic "Model Ports.jpg" shows.

Could anyone offer any help please?

Thanks

[Fangjun Jiang]

You have to show the S-function source code to debug the problem.

[Crispin Zuercher]

Sorry; I assumed it'd be with the model I uploaded.

I've tweaked the model somewhat since asking this question, however the problem still persists. Here is the source code:

function [Wheel_Force,Body_Force] = fcn(x1, x2, x3, x4, Kt, Ks, Cs,Ms,Mu,Alpha)
A = [0 0 -1 0; 0 0 1 -1; Kt/Mu (-Ks/Mu) (-Cs/Mu) Cs/Mu; 0 Ks/Ms Cs/Ms (-Cs/Ms)];
B = [0; 0; -1; 1];
R = (1/(Ms^2));
Q = [Alpha 0 0 0; 0 ((Ks^2)/(Ms^2)) ((Ks*Cs)/(Ms^2)) (-(Ks*Cs)/(Ms^2));...
    0 ((Ks*Cs)/(Ms^2)) ((Cs^2)/(Ms^2)) (-(Cs^2)/(Ms^2)); 0 (-(Ks*Cs)/(Ms^2)) (-(Cs^2)/(Ms^2)) ((Cs^2)/(Ms^2))];

A_Trans = transpose(A);
R_Inverse = inverse(R);
B_Trans = transpose(B);

Coeff_Matrix = (A_Trans + A - (B*R_Inverse*B_Trans));
Coeff_Inverse = inverse(Coeff_Matrix);
P = (Q*-1)*Coeff_Inverse;

K = R_Inverse*B_Trans*P;

Wheel_Force = (-K(3)*x3);
Body_Force = (-K(4)*x4);

[Liping]

Can you help me to solve the same problem?

Error in default port dimensions function of S-function 'fangzhen22/Embedded MATLAB Function'. This function does not fully set the dimensions of output port 2

[Fangjun Jiang]

Look at the .jpg file in the original question, find the similar place for your Embedded MATLAB Function block, change the "size" of "FS" from -1 to something else, likely 1 if your FS is a scalar.

Answer 1

[Fangjun Jiang]

This is not a Simulink S-function. It is a MATLAB Function block.

Anyway, as you've shown in your attached image, just explicitly specify the "size" for "F1". For example, it seems that the size of "F1" can be set as 1.