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Re: [TRNSYS-users] type 9 problem

Title: Message
Dear Stefan and Constanze,

Thanks, Stefan, for answering this question. But I am afraid that there is a mistake in your explanation.

Concerning the first question, I think the problem is that trnsys only accepts timesteps which have a value of 2^n, in which n is an integer (pos. or neg.) value. You could try 2^-4 (0.0625).

There is not such limit in TRNSYS.  You can use any value of time step, for example 3.14159 and it will work.
However, some components have constraints on the relation between internal variables and the simulation time step.  Type9 is one of them.
Constanze, I suggest that you check the value of the time step and the value of the parameter 4 in type9:
- Set parameter 4 to 0.0833 h, (i.e., 5 min).
- Then, you can use as time step a fraction of this number, such as 0.0833, 0.04165, 0.02777, 0.02082 (... Parameter4 / n where n is an integer).

Please let me know if this works.
Best regards,

Diego



 

Attached you find an example of type 9. Put it in My documents together with the scheme.txt. I hope it’s useful

 

Good luck

stefan

 

Van: trnsys-users-bounces@engr.wisc.edu [mailto:trnsys-users-bounces@engr.wisc.edu] Namens Constanze.Bongs@csiro.au
Verzonden: donderdag 1 juni 2006 7:48
Aan: trnsys-users@engr.wisc.edu
Onderwerp: [TRNSYS-users] type 9 problem

 

Hi,

 

I am new to using TRNSYS and have run across the following problem which I could not resolve using the manual or the mailing list archives. It is probably really easy but I would be very happy if someone could give me a “helping hand”.

 

I want TRNSYS to read data (temperatures and relative humidity) from an excel file and use that data as input to a building model. The data in the sheet is taken at time steps of  5 minutes. I tried using TYPE 9 to read it.  However, when I try running the simulation (or Type 9 separately) I get the following error messages:

1.) The system does not seem to allow me to input data time steps of less than 1 hour into parameter 4 (time interval of data) – although it should if I am well informed. I tried to use hrs as unit and filled in 1/12 or 0,0833 but still the same problem occurred. If I set it back at 1 hr it does not give me the error message any more, but that does not make sense with the data I want to use.

2.) Using 1 hr (to see if the type works) I get the error message that the system is not able to read the file correctly. I inserted the path to the file under external files (and under files in the window that opens as I click on information). I checked the deck file and it gives me the right path to the excel sheet. I also checked the excel sheet but can find no error in the sheet. However, I cannot get TRNSYS to run the simulation (type 9) and read the file.

 

Well, hope someone can help.

 

Cheers,

 

Constanze

 

 

-------------------------------------------------------------

Constanze Bongs

CSIRO Division of Energy Technology

 

Constanze.Bongs@csiro.au

Ph: 02 4960 6104

fax: 02 4960 6111

-------------------------------------------------------------

 



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