Pfthb

I have one Modelica model :

model test
 Real x;
 Real y (start=10);

function try
 input Real x;
 output Real y; 
 external "C" testC(x,y)
 annotation(Include="#include <test.c>");
end try;

function round
 input Real u;
 input Real accuracy;
 output Real y;
algorithm
 y :=if (u > 0) then floor(u/accuracy + 0.5)*accuracy else ceil(u/accuracy - 0.5)*accuracy;
end round;

algorithm
 x:=round(time, 60);
 when time>=pre(y) then
 y:=try(x);
 end when;
end test;

And the c code is also shown as below:

int testC(double x, double* y)

 puts("run ex");
 *y=x+30;

The above code works well in Dymola, but when I run it in JModelica, I got one issue:

When simulate this model in period [0,200], I expect the c function will be called by 4 times: t=10,30,90,150. But I found in Jmodelica, the c function is actually called by 24 times!

Any help to explain the above issue will be highly appreciated.

Just some small corrections and improvements, e.g., make it a void function.

model Test
 Real x;
 discrete Real y(start=10, fixed=true);

function try
 input Real x;
 output Real y; 
 external "C" testC(x,y)
 annotation(Include="
void testC(double x, double* y)

 *y=x+30;
");
end try;

function round
 input Real u;
 input Real accuracy;
 output Real y;
algorithm
 y :=if (u > 0) then floor(u/accuracy + 0.5)*accuracy else ceil(u/accuracy - 0.5)*accuracy;
end round;

algorithm
 x:=round(time, 60);
 when time>=pre(y) then
 y:=try(x);
 end when;
annotation(experiment(StopTime=200));
end Test;

Btw, unrelated to FMI.