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Setting a simulation to run for a full month results in an I_LENGTH value of 28.
For example Jan 1 - Feb 1, May 1 - June 1. The Simulation start/stop time hours update correctly in the Settings dialog, but the DCK always has 28 as the I_LENGTH value. I can't seem to figure out any rhyme or reason to the value.
- May 1 - April 1 => I_DAY = 28
- Jan 1 - Jan 1 12 h => 8016
- Jan 1 - Jan 14 => 7
- Jan 1 - Jan 21 => 14
- Jan 1 - Mar 1 => 56
- Jan 1 - Apr 1 (May 1, Jun 1, Jul 1 ...) => 56
- . . .
****************************************************************************
Control cards
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* START, STOP and STEP
*|[SIMPAR|Simulation Parameters
EQUATIONS 5
I_MONTH=2880
*|<Month of the simulation |C:\TRNSYS18\Exe\Month1.dat|1|2|2
I_DAY=1
*|Day of Month for Simulation Start |||0|1|1|31|3
I_LENGTH=28
*|<Length of Simulation |C:\TRNSYS18\Exe\Length.dat|2|1|4
START=I_MONTH+24*(I_DAY-1)
STOP=START+I_LENGTH*24
EQUATIONS 1
STEP=5/60
*|Timestep |hours|hours|0|1|0.0000277777778|10000.00000|1000
*|]
SIMULATION START STOP STEP ! Start time End time Time step
I'm not sure why these equations are being used.
When I create a simple project: START, STOP, and STEP, are simply written directly to the deck file without the above equations.
I have resorted to simply running 28-day long simulations for now 🙁
The snippet you included is from a TRNSED file (*.trd) and not a deck file (*.dck). The extra comments in the file are there to define the user interface for selecting parameters. In this case, the simulation length is supposed to be user-selected from a file called length.dat. If you are not using TRNSED to select the parameters, you should be able to change the value of I_LENGTH to the number of days you want to simulate.
