[TRNSYS-users] TRNSYS15 startime

Diego A. Arias daarias at wisc.edu
Thu Jan 12 08:42:16 PST 2006

Dear Henk,

Sorry for taking so long to reply to you.  This problem was solved in 
TRNSYS16.  Quoting TRNSYS16 manual, "Throughout much of TRNSYS' history, 
there was no call to components at the simulation start time.  After 
being called with INFO(7) =-1 for initialization,  Types were called at 
the end of the first time step.  In TRNSYS16, Types are called after 
they have been initialized and before time has advanced in the 
simulation.  They set the initial values of the outputs during the start 
Best regards,


henkwitte wrote:

> In TRNSYS15 the results of the first timestep are always zero (e.g. 
> the Sens Energy Demand from Type56 is zero at the
>>> end of the first hour of the simulation). This is especially a 
>>> problem in restarting simulations. How can I prevent this?
>> You can start your simulation some time before your time of interest.
>> For example, you can start your simulation on December 1st, and run 
>> the simulation until the end of the next year.  You will neglect the 
>> results for the first December.
> Yes, but that won't solve the restart problem. When restarting the 
> first "forcing" is neglected, but it shouldn't be!
> In the restart the module I use reads in a file saved during a 
> previous run and resumes the calculations. Now, if
> I run the whole simulation at once, the very first timestep is 
> neglected and the rest of the simulation is continuous.
> However, if I restart the first timestep of the restart (say, the 
> 43800 step of the complete simulation) is again
> neglected and the results are not continuous.
> Can that be solved (i.e. can you force TRNSYS to actually calculate 
> the first timestep as well?).


Diego A. Arias
TRNSYS Coordinator
Solar Energy Laboratory
University of Wisconsin - Madison
1500 Engineering Drive
Madison, WI 53706

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