[TRNSYS-users] Overflow problem

[Michaël Kummert]

Leen,

> I get an overflow problem, even after changing the mode of the Fortran 
> Compiler into a release mode. It happens after a simulation of more than 
> 7900 hours, when it had to simulate 8760 hours.

Integer and floating point overflows are the kind of errors that are 
hard to track in the listing file only, so you might have to use the 
compiler debugger. You can have conditional breakpoints (e.g. if TIME> 
7899 hours) and go step by step from there. I have a mixed experience 
using CVF's conditional breakpoints so I sometimes simply add a section 
in one of the Types that says something like:

if (TIME > 7899.0) then
     continue
endif

and put a breakpoint on "continue".

> Is there another solution? Does it help to change the simulation step 
> into another one?

It is hard to tell without further information on your simulation. I 
could imagine a counter overflowing if the number of time steps it too 
large so you could try increasing the time step if you currently use a 
short one.

> Another problem is that TRNSYS wan't show the List file by pressing the 
> button, but gives it 15 minutes later.

This is a known issue in TRNList, the program IISiBat uses to display 
the listing file. TRNList parses the list file for errors before 
displaying it so it can take very long for huge listing files. You can 
open the LST file in notepad, it is usually much faster.

Note that since your listing file is so big, there are chances you will 
find some information on what goes wrong in the simulation and possibly 
what causes the overflow.

As always, if you cannot find a solution or if you suspect a problem in 
the TRNSYS code, feel free to send your project files to your distributor.

I hope this helps,

Michaël Kummert

-- 
_________________________________________________________

Michaël Kummert

Solar Energy Laboratory - University of Wisconsin-Madison
1303 Engr Res Bldg, 1500 Engineering Drive
Madison, WI 53706

Tel: +1 (608) 263-1589
Fax: +1 (608) 262-8464
E-mail: kummert at engr.wisc.edu

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TRNSYS Web Site: http://sel.me.wisc.edu/trnsys