how to embed matlab function simulink

How to call this code in simulink while running as one of it's blocks

% intialization global Iref; global Increment; global Pold; Pold=0; Iref=4; Increment = -1;

function y = MPPtrackIref(P)

global Pold; global Iref; global Increment; IrefH = 5; IrefL =0; DeltaI = .02

if (P < Pold) Increment = - Increment; end

Iref = Iref + Increment*DeltaI

end

Pold = P; y = Iref;

[Azzi Abdelmalek]

What is the version of Matlab, what is your error message?

[Walter Roberson]

Please read the guide to tags and retag this question; see http://www.mathworks.co.uk/matlabcentral/answers/43073-a-guide-to-tags

Answer 1

[Azzi Abdelmalek]

You don't need to use global variables, just use constant blocks and pass them through your matlab function

Answer 2

[Kaustubha Govind]

As explained in this previously asked question, it appears that you need to use global variables inside MATLAB Function blocks in conjunction with Data Store Memory blocks. If you really just mean to use those global variables as persistent memory, you should try:

function y = MPPtrackIref(P)

persistent Pold Iref Increment; 
if isempty(Pold)
   Pold=0; %initialized only once in the beginning
end
if isempty(Iref)
   Iref=4; %initialized only once in the beginning
end
if isempty(Increment)
   Increment = -1; %initialized only once in the beginning
end

IrefH = 5; IrefL =0; DeltaI = .02;

if (P < Pold) 
  Increment = - Increment; 
end

Iref = Iref + Increment*DeltaI;

end

Pold = P; 
y = Iref;

Answer 3

[Julien]

Hi, You can use the ' Matlab function ' block (found inside user-defined function library )

But this simple function can also be defined with usual simulinks block (with boolean test and unit delay blocks).

Why do you need to define your constants as global variable ?

Answer 4

[mado]

I used matlab function but it gives me error , i can't write it in script file as it doesn't accept function and i can't write it in a function as it doesn't accept first declarations

Answer 5

[mado]

how to pass them ??

[Azzi Abdelmalek]

add a constant block and set a constant value to variable v (for example). in your m file or matlab command assign a value to your variable v