Guard it with external C code. Give it a unique identifier so you can guard multiple sections.

if once(13) then

 ...

end if;

Hi sjoelund.se,

thanks for your answer. I fear i don't see your point. Without further means, the algorithm is executed over and over again, until the end of the simulation duration, but i want it to be executed exactly once.

--Paul

The part inside you have guarded with an expression in an external function that you made sure would only return true once.
The algorithm section will be called every time-step, but the part inside only once.

Thanks

--Paul