Simulink: MATLAB Function Doesn't Recognise Variables

Hi All,

I have created this a MATLAB Function in simulink which I would like to run. This function uses certain variables which I have loaded in through the PreLoadFcn as follow:

This is the code inside my function:

function G = fcn(v,vp,gp)

if v <= Up2 & vp < Up2 | v <= Dn1 & vp > Dn1;

G=1;

elseif Up2 < v & v <= Up3 & vp < Up3 | Dn1 < vp & vp < Dn2;

G=2;

elseif Up3 < v & v <= Up4 & vp < Up4 | Dn2 < vp & vp < Dn3;

G=3;

elseif Up4 < v & v <= Up5 & vp < Up5 | Dn3 < vp & vp < Dn4;

G=4;

elseif Up5 < v & v <= Up6 & vp < Up6 | Dn4 < vp & vp < Dn5;

G=5;

elseif Up6 < v & Up6 < vp | Dn5 < v & Gp==6

G=6,

else

disp("LOGIC ERROR")

end

I saved the simulation and reopened it. Then, I get these error messages after I click on the run button:

Why does the function not able access the variables above?

Answer 1

[cr]

Of course it doesn't. That is intended behaviour. Functions have their own workspace which is distinct from base workspace (or model workspace). If you need the function to use the variables/parameters declared in preloadfcn, you must pass in these variables separately. You may use a from workspace block and input it to additional input port(s) on the fcn block. Your fcn definition may become something like

function G = fcn(v,vp,gp,Up1,Up2,Up3,Up4,Up5,Dn1,Dn2,Dn3,Dn4,Dn5)

or better, mux all ups and dns into two signals, say ups and dns and use

fcn(v,vp,gp,ups,dns)

Regards