[TRNSYS-users] Floating point error with Type 155 (Matlab) and Online Plotter

Thomas Krummrein thomas.krummrein at web.de
Thu Apr 11 02:50:57 PDT 2013

Hi Everybody,
I use TRNSYS 16 and I have recomiled it with the Intel Visual Fortran compiler. If I use the Type 155 (Calling Matlab) everything works fine as long as I do not use the Online Plotter (Type 65). If I use the Online plotter, I get the error message "Invalid floating point operation." at the very beginning of the simulation and TRNSYS aborts. This happens always, it is not needed, that the Online plotter is connected to anything (One Exception: If the Parameters "Nb. of left-axis variables" and "Nb. of right-axis variables" are both 0, than everything works. But I think that then the online plotter is ignored).

Has anyone an idea, what I can do against this error or why Type 155 and the online plotter are not compatible with each other?

I have figured out that the calculation way to the error is the following, maybe this helps: Type 65 is called with info(7)=-2 and then with info(7)=-1 without problems, the same is done with type 155. Calling Type 65 with info(7)=0 (first "normal" calculation) is OK, too. This call is done by the TRNExe.exe (which I can't debug), via the Subroutine TRNSYS (trnsys.for) and some other subroutines. After this call of type 65 with info(7)=0 the program goes back to TRNExe.exe without problems. In the next call of the Subfunction TRNSYS nothing happens, because it goes more or less directly to a "return", so that the program goes back tot TRNExe. This "return"-Line has the comment "If this is the first time the DLL is called with ICALL=1, return immediately so that the EXE can plot the initial conditions calculated during the ICALL=0 call" and is located in trnsys.for, line 544. After this "return" the error appears (This means the program should be somewhere in TRNExe, when the error is produced).

Thanks for any help
Tobias Mayer

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