Return function doesn't work after a while

Good afternoon everybody,

I have an issue with one of my Matlab script. I will try to explain clearly my problem. I've linked the software TRNSYS with Matlab. Basically, TRNSYS calls a Matlab script at every timestep. When I wrote the Matlab code, I've used a small simulation time (only 48 hours) in order to check that everything was working. And it was working without any problem.

However, when I increases the simulation time, the simulation blocked after many hours (the number of hours depends on the starting time of my simulation, but I don't find any logic. Sometimes it stops working after 50 hours, sometimes after 600...). I've used the dbstop function to understand the problem, and I think that the problem comes from the "return function" at the end. Indeed, during the first hours, the return function works without any problem: at each time that the program reaches the return, the timestep of my simulation increases. However, after a while, when the program reaches the return, the program come back to the beginning of the matlab program without increasing the TRNSYS simulation timestep.

Since the return is not dependent of any other value (from my knowledge), I really don't understand how it may work perfectly at the beginning and stop working after. Do you have any idea for me of what it may come from ?

Thanks a lot for your time and your help ! Hélène

[Geoff Hayes]

Hélène - can you tell us more about what your function does? Do you increment a counter indicating which tilmestep you are at? How often do you call your function? Are you keeping track of an array of data which gets updated at each call to your function?

You may want to provide a small sample of your code so that we can get a better idea of what is happening.

[Hélène T.]

Thanks a lot for your response. You can find on this message all my code. Since I am not sure of what is relevant, I prefer give you everything.

To summarize what my code is doing: I receive some information from my TRNSYS program at every timestep (my Inputs). You can find the timestep iStep in the next that is the hour of my simulation in TRNSYS. As an example, if I start my simulation at 744 hours in TRNSYS to not consider the first month, iStep will be 744 (even if I am not sure why...). On the contrary, TimeStep will be the number of the timestep (always 1 at the beginning). I do some calculations from these values. Some matrix are updates at every time step (as E1_mod and E2_mod). Finally, my code sent to TRNSYS some information. The "return" that I mentioned in my previous message is the last word of the code.

I am sorry, I am aware that my code is not easy to read for other people than me... I hope it will be ok.

Again, thanks a lot for your time and help !

    % Type155_CallingMatlab.m
% ----------------------------------------------------------------------------------------------------------------------
%
% Example M-file called by TRNSYS Type 155
%
% Data passed from / to TRNSYS 
% ---------------------------- 
%
% trnTime (1x1)        : simulation time 
% trnInfo (15x1)       : TRNSYS info array
% trnInputs (nIx1)     : TRNSYS inputs 
% trnStartTime (1x1)   : TRNSYS Simulation Start time
% trnStopTime (1x1)    : TRNSYS Simulation Stop time
% trnTimeStep (1x1)    : TRNSYS Simulation time step
% mFileErrorCode (1x1) : Error code for this m-file. It is set to 1 by TRNSYS and the m-file should set it to 0 at the
%                        end to indicate that the call was successful. Any non-zero value will stop the simulation
% trnOutputs (nOx1)    : TRNSYS outputs  
%
% 
% Notes: 
% ------
% 
% You can use the values of trnInfo(7), trnInfo(8) and trnInfo(13) to identify the call (e.g. first iteration, etc.)
% Real-time controllers (callingMode = 10) will only be called once per time step with trnInfo(13) = 1 (after convergence)
% 
% The number of inputs is given by trnInfo(3)
% The number of expected outputs is given by trnInfo(6)
% WARNING: if multiple units of Type 155 are used, the variables passed from/to TRNSYS will be sized according to  
%          the maximum required by all units. You should cope with that by only using the part of the arrays that is 
%          really used by the current m-File. Example: use "nI = trnInfo(3); myInputs = trnInputs(1:nI);" 
%                                                      rather than "MyInputs = trnInputs;" 
%          Please also note that all m-files share the same workspace in Matlab (they are "scripts", not "functions") so
%          variables like trnInfo, trnTime, etc. will be overwritten at each call. 
%          "Local" variables like iCall, iStep in this example will also be shared by all units 
%          (i.e. they should be given a different name in each m-File if required)
%
% ----------------------------------------------------------------------------------------------------------------------
% This example implements a very simple component. The component is iterative (should be called at each TRNSYS call)
%
%
% MKu, October 2004
% ----------------------------------------------------------------------------------------------------------------------
% TRNSYS sets mFileErrorCode = 1 at the beginning of the M-File for error detection
% This file increments mFileErrorCode at different places. If an error occurs in the m-file the last succesful step will
% be indicated by mFileErrorCode, which is displayed in the TRNSYS error message
% At the very end, the m-file sets mFileErrorCode to 0 to indicate that everything was OK
mFileErrorCode = 1000;    % Beginning of the m-file 
% --- Process Inputs and global parameters -----------------------------------------------------------------------------
% ----------------------------------------------------------------------------------------------------------------------
nI = trnInfo(3); % number of inputs: time step - hour - half day solar radiation amount - half day min T
nO = trnInfo(6); %number of outputs
% MyInput = trnInputs(1);
Hour=trnInputs(1);
% Feedback
Tin(1)=trnInputs(2);
Tin(2)=trnInputs(3);
Tin(3)=trnInputs(4);
Tin(4)=trnInputs(5);
Tin(5)=trnInputs(6);
Tin(6)=trnInputs(7);
Tsurf(1)=trnInputs(8);
Tsurf(2)=trnInputs(9);
Tsurf(3)=trnInputs(10);
Tsurf(4)=trnInputs(11);
Tsurf(5)=trnInputs(12);
Tsurf(6)=trnInputs(13);
Dayoftheyear=trnInputs(14);
SimulTimeStep=trnInputs(15);
mFileErrorCode = 900;    % After processing inputs
% --- First call of the simulation: initial time step (no iterations) --------------------------------------------------
% ----------------------------------------------------------------------------------------------------------------------
% (note that Matlab is initialized before this at the info(7) = -1 call, but the m-file is not called)
if ( (trnInfo(7) == 0) & (trnTime-trnStartTime < 1e-6) )  
        % This is the first call (Counter will be incremented later for this very first call)
    iCall = 0;
    % This is the first time step
    iStep = 1;
        % Do some initialization stuff, e.g. initialize history of the variables for plotting at the end of the simulation
    % (uncomment lines if you wish to store variables) 
    nTimeSteps = (trnStopTime-trnStartTime)/trnTimeStep + 1;
    history.inputs = zeros(nTimeSteps,nI);
    Day=0;
    mFileErrorCode = 910; 
    %Predictions
    Data1=dlmread('C:\Users\Helene\Dropbox\Master\Model\Models finaux\6-Learning - No basement\SolarPred_NovJan_amount.txt','\t',0,0);
    Data2=dlmread('C:\Users\Helene\Dropbox\Master\Model\Models finaux\6-Learning - No basement\TemperaturePred_NovJan.txt','\t',0,0);
    NbreData=62;
    TimeStep=1;
        T_category=14; %Number of temperature categories
    S_category=3; %Number of solar categories
    mFileErrorCode = 920; 
    min_T_1=zeros(NbreData,1);
    min_T_2=zeros(NbreData,1);
    for n=1:NbreData
                Morning_solar_amount(n,1)=sum(Data1(n,1:12));
        Afternoon_solar_amount(n,1)=sum(Data1(n,13:24));
                MinT1(n,1)=min(Data2(n,1:12));
        MinT2(n,1)=min(Data2(n,13:24));
                i=1;
        while min_T_1(n,1)==0
            if i<T_category
                if MinT1(n,1)<(-40+i*5)
                    min_T_1(n,1)=i;
                end
               i=i+1;  
            else min_T_1(n,1)=T_category;
            end
        end
        i2=1;
        while min_T_2(n,1)==0
            if i2<T_category
                if MinT2(n,1)<(-40+i2*5)
                    min_T_2(n,1)=i2;
                end
               i2=i2+1;  
            else min_T_2(n,1)=T_category;
            end
        end
    end
    mFileErrorCode = 930;  
    Room=6;
    E1_mod=1000*ones(T_category, S_category, Room, nTimeSteps); 
    E2_mod=1000*ones(T_category, S_category, Room, nTimeSteps); 
    SimTimeStep=zeros(nTimeSteps,1);
        mFileErrorCode = 931;  
        Ini_con_morning=40*8; %Initial consumption for the morning in Wh/m2
    Ini_con_afternoon=0; %Initial consumption for the afternoon
    mFileErrorCode = 932;  
    E1_ini=Ini_con_morning*ones(T_category, S_category,Room);
    E2_ini=Ini_con_afternoon*ones(T_category, S_category,Room);
    mFileErrorCode = 933;  
    Power=zeros(6,1); %Power that will be sent at every time step
    mFileErrorCode = 940; 
        Start_time_1=zeros(Room,1);
    Start_time_2=zeros(Room,1);
    Stop_time_1=zeros(Room,1);
    Stop_time_2=zeros(Room,1);
        %Building analysis
    Tin_lastday=ones(6,288)*21;
    Power_applied=zeros(6,288);
    un_coef=0.8; %Coefficient i.e. un_coef % of the values in E_mod should be lower of the chosen value
    % No return, normal calculations are also performed during this call
    mFileErrorCode = 800;    % After initialization call
    end
% --- Very last call of the simulation (after the user clicks "OK") ----------------------------------------------------
% ----------------------------------------------------------------------------------------------------------------------
if ( trnInfo(8) == -1 )
    mFileErrorCode = 700;
        % Do stuff at the end of the simulation, e.g. calculate stats, draw plots, etc... 
            mFileErrorCode = 0; % Tell TRNSYS that we reached the end of the m-file without errors
    return
end
% --- Post convergence calls: store values -----------------------------------------------------------------------------
% ----------------------------------------------------------------------------------------------------------------------
if (trnInfo(13) == 1)
        mFileErrorCode = 600;   % Beginning of a post-convergence call 
    % This is the extra call that indicates that all Units have converged. You should do things like: 
    % - calculate control signal that should be applied at next time step
    % - Store history of variables
    for r=1:6
        Power_applied(r,mod(iStep,288)+1)=Power(r,1);
    end
    % Note: If Calling Mode is set to 10, Matlab will not be called during iterative calls.
    % In that case only this loop will be executed and things like incrementing the "iStep" counter should be done here
        mFileErrorCode = 0; % Tell TRNSYS that we reached the end of the m-file without errors
    return  % Do not update outputs at this call
end
% --- All iterative calls ----------------------------------------------------------------------------------------------
% ----------------------------------------------------------------------------------------------------------------------
% --- Process Inputs ---
mFileErrorCode = 190;   % Beginning of iterative call
% Do calculations here
%Store indoor temperature values
for r=1:6
    Tin_lastday(r,mod(iStep,288)+1)=Tin(r);
end
mFileErrorCode = 180; 
iStep = iStep+1;
TimeStep=TimeStep+1;
if mod(iStep,288)==0 %high-level controller %If simulation starts at 22h
        Day=Day+1;
        S1=Solar_rad_learning(Morning_solar_amount(Day,1),S_category);
       S2=Solar_rad_learning(Afternoon_solar_amount(Day,1),S_category);
        T1=min_T_1(Day,1);
        T2=min_T_2(Day,1);
        mFileErrorCode = 170; 
        %Building Analysis
    for r=1:6
        Tmax_1(r,1)=max(Tin_lastday(r,1:144));
        Tmax_2(r,1)=max(Tin_lastday(r,145:288));
        Tmin_1(r,1)=min(Tin_lastday(r,1:144));
        Tmin_2(r,1)=min(Tin_lastday(r,145:288));
        Consumption_applied_1(r,1)=sum(Power_applied(r,1:144)*0.08333);
        Consumption_applied_2(r,1)=sum(Power_applied(r,145:288)*0.08333);
           if Tmax_1(r,1)>23 
            Emod_1(T1,S1,r,TimeStep)=Consumption_applied_1(r,1)*(1-un_coef);
            if Tmin_2(r,1)<20 
               Emod_2(T2,S2,r,TimeStep)=Consumption_applied_2(r,1)*(1+un_coef);
            else
                if Tmax_2(r,1)>23
                Emod_2(T2,S2,r,TimeStep)=Consumption_applied_2(r,1)*(1-un_coef);
                else
                Emod_2(T2,S2,r,TimeStep)=Consumption_applied_2(r,1);
                end
            end
        else
            if Tmin_1(r,1)<20
            Emod_1(T1,S1,r,TimeStep)=Consumption_applied_1(r,1)*(1+un_coef);
            Emod_2(T2,S2,r,TimeStep)=Consumption_applied_2(r,1);
            else
            Emod_1(T1,S1,r,TimeStep)=Consumption_applied_1(r,1);
            if Tmin_2(r,1)<20 
                if Tmax_1(r,1)>22 
                Emod_1(T1,S1,r,TimeStep)=Consumption_applied_1(r,1)*(1+un_coef); %check pour 2
                else Emod_2(T2,S2,r,TimeStep)=Consumption_applied_2(r,1)*(1+un_coef);
                end
            else
                if Tmax_2(r,1)>23
                Emod_2(T2,S2,r,TimeStep)=Consumption_applied_2(r,1)*(1-un_coef);
                else Emod_2(T2,S2,r,TimeStep)=Consumption_applied_2(r,1);
                end
            end
        end
        end
    end
             mFileErrorCode = 160;     
            %Update of the initialization matrix
        for r=1:6
        for t=1:T_category %For the morning update
            for s=1:S_category
                if T1>t && s==S1
                    if E1_mod(T1,S1,r,TimeStep)>E1_ini(t,S1,r)
                        E1_ini(t,S1,r)=E1_mod(T1,S1,r, iStep);
                    end
                end
                 if T1<t && s==S1
                    if E1_mod(T1,S1,r,TimeStep)<E1_ini(t,S1,r)
                        E1_ini(t,S1,r)=E1_mod(T1,S1,r,iStep);
                    end
                 end
                 if S1>s && t==T1
                    if E1_mod(T1,S1,r,TimeStep)>E1_ini(T1,s,r)
                        E1_ini(T1,s,r)=E1_mod(T1,S1,r,iStep);
                    end
                 end
                  if S1<s && t==T1
                    if E1_mod(T1,S1,r,TimeStep)<E1_ini(T1,s,r)
                        E1_ini(T1,s,r)=E1_mod(T1,S1,r,iStep);
                    end
                  end
            end
        end
        end
        mFileErrorCode = 150; 
for r=1:6
        for t=1:T_category %For the afternoon update
            for s=1:S_category
                if T2>t && s==S2
                    if E2_mod(T2,S2,r,TimeStep)>E2_ini(t,S2,r)
                        E2_ini(t,S2,r)=E2_mod(T2,S2,r,iStep);
                    end
                end
                 if T2<t && s==S2
                    if E2_mod(T2,S2,r,TimeStep)<E2_ini(t,S2,r)
                        E2_ini(t,S2,r)=E2_mod(T2,S2,r,iStep);
                    end
                 end
                 if S2>s && t==T2
                    if E2_mod(T2,S2,r,TimeStep)>E2_ini(T2,s,r)
                        E2_ini(T2,s,r)=E2_mod(T2,S2,r,iStep);
                    end
                 end
                  if S2<s && t==T2
                    if E2_mod(T2,S2,r,TimeStep)<E2_ini(T2,s,r)
                        E2_ini(T2,s,r)=E2_mod(T2,S2,r,iStep);
                    end
                  end
            end
        end
end
        mFileErrorCode = 140; 
                %Choice of the output value
   for r=1:6
        if min(E1_mod(T1,S1,r,:))==1000
            E_1(r,1)=E1_ini(T1,S1,r);
        else 
            Array_E1_mod=sort(E1_mod(T1,S1,r,:));
             Index_1=find(Array_E1_mod==1000, 1);
             Reduced_Array_E1_mod=Array_E1_mod(1,1:Index_1);
            E_1(r,1)=Reduced_Array_E1_mod(1,floor(size(Reduced_Array_E1_mod,2)*un_coef));
        end

        if min(E2_mod(T2,S2,r,:))==1000
            E_2(r,1)=E2_ini(T2,S2,r);
        else 
            Array_E2_mod=sort(E2_mod(T2,S2,r,:));
             Index_2=find(Array_E2_mod==1000, 1);
             Reduced_Array_E2_mod=Array_E2_mod(1,1:Index_2);
             E_2(r,1)=Reduced_Array_E2_mod(1,floor(size(Reduced_Array_E2_mod,2)*un_coef));
        end
   end
        mFileErrorCode = 130; 

        %Load Management
 for r=1:6 
        Power_1(r,1)=80; %W/m2
        D_1(r,1)=E_1(r,1)/Power_1(r,1);
        Power_2(r,1)=40; %W/m2
        D_2(r,1)=E_2(r,1)/Power_2(r,1);

        if D_1(r,1)>8
            D_1(r,1)=8;
            Power_1(r,1)=E_1(r,1)/D_1(r,1);
            if Power_1(r,1)>120
                Power_1(r,1)=120;
                D_2(r,1)=E_2(r,1)+E_1(r,1)-(Power_1(r,1)*D_1(r,1));
            end
        end
        if D_2(r,1)>6
            D_2(r,1)=6;
            if Power_1(r,1)<120
            D_1(r,1)=E_2(r,1)+E_1(r,1)-(Power_2(r,1)*D_2(r,1));
            else 
            Power_2(r,1)=E_2(r,1)/D_2(r,1);
            if Power_2(r,1)>120
                Power_2(r,1)=120;
            end
            end
        end
        if D_1(r,1)>8
            D_1(r,1)=8;
            Power_1(r,1)=E_1(r,1)/D_1(r,1);
            if Power_1(r,1)>120
                Power_1(r,1)=120;
                D_2(r,1)=E_2(r,1)+E_1(r,1)-(Power_1(r,1)*D_1(r,1));
            end
        end
        if D_2(r,1)>6
            D_2(r,1)=6;
        end

        if D_1(r,1)<=4
            Start_time_1(r,1)=2;
            Stop_time_1(r,1)=2+D_1(r,1);
        else
            if D_1(r,1)>6
                Start_time_1(r,1)=24-(D_1(r,1)-6);
            else
            Start_time_1(r,1)=6-D_1(r,1);
            Stop_time_1(r,1)=6;
            end
        end
        Start_time_2(r,1)=16-D_2(r,1);
        Stop_time_2(r,1)=16;              
        end
 end
    mFileErrorCode = 120; 
      %low-level controller
for r=1:6
    Start_time_1(r,1)
    Stop_time_1(r,1)
    if and((Start_time_1(r,1)<Hour),(Hour<Stop_time_1(r,1)))
            if  Tin(r)<20
                Power(r,1)=max(Power_1(r,1),60);
            else Power(r,1)=Power_1(r,1);
            end
            else Power(r,1)=0;
    end
        if (Start_time_2(r,1)<Hour) && (Hour<Stop_time_2(r,1))
            if  Tin(r)<20
                Power(r,1)=max(Power_2(r,1),60);
            else Power(r,1)=Power_2(r,1);
             end
         else Power(r,1)=0;
        end
    if  Tin(r)<20
        if Power(r,1)<60
            Power(r,1)=60;
        end 
    end
    if Tin(r)>23
        Power(r,1)=0;
    elseif Tsurf(r)>28
            Power(r,1)=0;
    end
end
        mFileErrorCode = 110;         
  % --- Set outputs ---
trnOutputs(1) = Power(1,1);
trnOutputs(2) = Power(2,1);
trnOutputs(3) = Power(3,1);
trnOutputs(4) = Power(4,1);
trnOutputs(5) = Power(5,1);
trnOutputs(6) = Power(6,1);
mFileErrorCode = 0; % Tell TRNSYS that we reached the end of the m-file without errors
return

[Hadi Ramin]

Hello, I am going to perform whole building optimization using heuristic algorithm in matlab and Transys. do you know how to connect matlab and transys? Thank you so much

Answer 1

[Jan]

I can guarantee, that return is not the problem. I promise this.

You wrote:

 However, after a while, when the program reaches the return, the program come back
 to the beginning of the matlab program without increasing the TRNSYS simulation timestep.

Then this is a problem in TRNSYS? The shown script reaches the final return, but the calling function does not proceed as expected?

[Hélène T.]

Thanks for your help ! Yes exactly. As an example, during the 50 first timestep, at each time step, I will see that TRNSYS calls Matlab correctly, Matlab read the script, and when it reaches the return, I can see that TRNSYS goes to the next time step, and the Matlab script is read again from the beginning. But the 51st time, when the program reaches the return, Matlab goes back to the beginning of the program, but apparently TRNSYS doesn't have the information that it has to go to the next time step. Therefore, matlab continue to calculate, but TRNSYS is blocked. That's why I was thinking that it was the return function.

Do you have any idea of what may be the problem ?

If it may help, as function of the start time that I chose (trnStartTime in my code), the problem doesn't appear at the same time step.

Answer 2

[Josef]

We also have this problem an we changed "Calling Mode" in Tab "Parameter" of the TRNSYS Type 155 from "0" (Standard iterative component) to "10" (Non-iterative component). According to the TRNSYS Programmers Guide this is suitable for controllers. And for us it worked so far we can see until now. We also implement some control algorithms to control energy systems for longterm simulation of at least one year. As I've seen from your code this is nearly the same. So have you already tried this?