Matlab function in Simulink

Hello,

I have problem with MATLAB function in Simulink - after Run values are always zero, while other parts of code (built in PID controller) are working quite good.

function PWMout  = myPID(valTarget,valPres, kp, ki, kd, Td, Ts,errorPrev,...
    PIDoutMax, PIDoutMin, errorTolerance)

upperBound = PIDoutMax - (PIDoutMax*(1-errorTolerance));
lowerBound = PIDoutMin - (PIDoutMin*(1-errorTolerance));

errPres = valTarget - valPres;

Pout = kp*(errPres - errorPrev);

Iout = ki*errPres;

Dout = kd*(Td/Ts)*(errPres - (2*errorPrev) + ...
    + errorPrev);

PIDoutTemp = Pout + Iout + Dout;

PWMout = PIDoutTemp;

errorPrev = errPres;

end

[Ameer Hamza]

Try adding a breakpoint inside the function to see whether what is causing the output to remain zero. https://www.mathworks.com/help/matlab/matlab_prog/set-breakpoints.html

[ps19]

Yes I know about debugging but code is in Subsystem/MATLAb function block and when I will add breakpoint it didn`t stop on it - it didn't matter which place in code of subsystem.

[Ameer Hamza]

Can you attach the model?

[ps19]

Yes no problem. In attachment

[Ameer Hamza]

I tried running the model. The brakpoint is working and it does give non zero value in PWMout.

[ps19]

It`s started working, I created new model recreated block by block, something must have been crashed in some configuration stage.

[Ameer Hamza]

Btw, look at persistent variables. You will need that to properly save PID values from the last step inside the function block.