synchronization of matlab function blocks

Dear all, I have a simulink model who contains 9 subsystems connected to each other via GoTo-From blocks, each subsystem has a matlab function block (should be the same block, I just copy past from the first subsystem to the other subsystems), my question is regarding the matlab function block, I need to change some variables inside the matlab function in the subsystem number one these variables should be changed instantly in the other blocks as well, I was looking for a way to define the matlab function block to be global or on other words how can I tell the simulink that this matlab function block is the same block in all subsystems so any change in any block either adding a code or updating variables during the simulation time will be instantly applied to the other blocks.

Also I have a question regarding the output of the matlab function block, can this output be treated as an array instead of separated values? The matlab function block code is :

function [UB11,UB12,UB13,UB21,UB22,UB23,UB31,UB32,UB33,I] = fcn %coder.extrinsic('fcn') coder.extrinsic('xlsread'); persistent U; U=zeros(3,3); U=xlsread('C:\Users\Documents\MATLAB\InputImage.xlsx'); UB11=U(1,1); UB12=U(1,2); UB13=U(1,3); UB21=U(2,1); UB22=U(2,2); UB23=U(2,3); UB31=U(3,1); UB32=U(3,2); UB33=U(3,3); I=1; Thank you in advance, Sali

Answer 1

[Mike Hosea]

The MATLAB Function Block can return arrays. The problem with your code is probably just that you can't return the persistent array. If you create an array UB = U and return UB instead of U, it should work.

As for the synchronization, there may be more direct ways of solving the problem that I don't know much about (tunable parameters?), but I think it should be possible to create a MATLAB function with persistent (or global) variables that acts as a repository. Something like

function [a,b,c] = myrepository(a,b,c)
persistent asaved bsaved csaved
if isempty(asaved)
    asaved = 0;
    bsaved = 0;
    csaved = 0;
end
if nargin == 0
    a = asaved;
    b = bsaved;
    c = csaved;
else
    asaved = a;
    bsaved = b;
    csaved = c;
end

That's a MATLAB function that lives in MATLAB somewhere on the path, not in your MATLAB function block. Then in your MATLAB function block you retrieve the data

    [a,b,c] = feval('myrepository');

and set the data

    feval('myrepository',a,b,c);

or declare it extrinsic near the beginning of your function

    coder.extrinsic('myrepository');

and get/set the data with

    [a,b,c] = myrepository;
    myrepository(a,b,c);

Of course you'll need to be sure to initialize the data in myrepository as appropriate before the simulation begins.

[sali]

Thank you so much for your help I'll try this solution.