Dll execute error

[nguyenthanhnam2310]

Recently I tried with the DLL function in FlexSim. 

I wrote a simple dll like adding two numbers of type double, but when I ran, it didn't return the total but only the first input number. 

I want to know why this happen and how to avoid it when I build the dll. 

Below is my code in dll

// C LIBRARY FOR INPUT/OUTPUT STREAMS

#include <stdio.h>

#include <math.h>

// IN ORDER TO HAVE ACCESS TO FLEXSIM FUNCTIONS, INCLUDE FLEXSIMDEFS.H

#include "FlexsimDefs.h"

visible double dllcommand1(FLEXSIMINTERFACE)

{

// test passing parameters in usercommand

string par1=parstr(1);

pt("string parameter ");pt(par1);pr();

return 0;

}

visible double mydllfunction2(FLEXSIMINTERFACE)

{

pt("This will print to the Output Console");pr();

return 0;

}

visible double addfunction(double p1, double p2)

{

double a;

a = p1 + p2;

print(a); pr();

return a;

}

PS: the function mydllfunction2 is working fine, but the "addfunction" have the problem. I also attach my model too

[joerg_vogel_HsH · Accepted solution]

I have never done this before. But “a” is a command itself in FlexSim. So I would try to change the name of the local variable into a string that does not collide with any command featured in FlexSim or any other loaded library of the DLL.

[nguyenthanhnam2310]

I try with other way in the C++ source code, and it worked.

And I think it's good to name the function is not collide with other functions as you suggest.

Below is what I changed. 

visible double addfunction(FLEXSIMINTERFACE) 

{

double p1 = parval(1);

double p2 = parval(2);

double Total_2num;

Total_2num = p1 + p2;

print(Total_2num); pr();

return Total_2num;

}

Anyway, thank you for your advice.