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Hi,
I would like to use the average output value during the previous day in TRNSYS. In this forum, I have found that type 150 could be used for this purpose, but there is a limit of maximum 25 time steps in type 150. Since I use the time step 0.1 hr, the limit means that I can´t use type 150. Furthermore, I only want to do this calculation once in a day, not in every time step.
Does anyone know how this could be solved?
Best regards, Johan
There are (as with most things in TRNSYS) a few ways to approach this.
The limit of 25 time steps in Type 150 exists because the storage array in the Type is sized to only hold 25 values. That size (Max_Held) can easily be increased to 240 timesteps or more by re-compiling the source code and modifying the proforma (the icon in Simulation Studio that holds parameter/input/output settings). You may contact your TRNSYS distributor and request a modified .dll and proforma for Type150 with the increased limits. You may also re-compile the source code and change the proforma limits yourself. This video shows how to open and re-compile TRNSYS using Microsoft Visual Studio: Debugging Errors in TRNSYS Using Visual Studio. Visual Studio is free, and download and installation instructions are included in the first (chronological) comment on the video. Once the source code is changed, the proforma can be modified within Simulation Studio, as demonstrated here: Changing Cycle or Parameter Limits in a TRNSYS Proforma.
Another option would be to write your own Type similar to Type150. You could use TypeStudio with the source code from Type150 to write a Type identical to Type150 except with a larger Max_Held value, or you could go a step further and write the new Type to only save and update values every X hours or X timesteps, instead of saving and updating values on every timestep. More guidance on using TypeStudio and writing new Types is available in the ProgrammersGuide.pdf in the Documentation folder of your main TRNSYS directory.
A final possibility: I'm not sure which 'average output value during the previous day' you wish to use in your simulation, but if it's something read from external data (like an outdoor air temperature), you could do some pre-processing of your data, and create a data file you read into TRNSYS with average values from the previous day.
