Cramer,
Try inserting an equation. Create an output variable called "signal" or something. This variable will take on the value 1 for when the window is allowed to be opened; 0 for when it is not. Then, make signal equal to "and(ge(mod(time,24),8),le(mod(time,24),21))". Basically, this is saying: if the time is greater than or equal to 8 AND less than or equal to 21, then output the value 1, otherwise it takes on zero. If the type you're using uses an input that is a control signal, then this equation can be directly linked to it. I confirmed that the equation works by connecting the equation to an online plotter. Hope that helps.
Liam O'Brien
Date: Fri, 12 Sep 2008 19:01:55 +0200
From: silkworth@transsolar.com
To: trnsys-users@engr.wisc.edu
Subject: [TRNSYS-users] changing value only under certain conditions
Hi
All,
I'm trying to model
manually-operated windows, ie that can only be opened or closed when
someone is around to do it. Thus, I need a way to modify a variable only at
certain times - for example, so I can change my airchange rate
accroding to outdoor temp **only if** hr>8 and hr<21. I know of type
93 (input value recall), but can't think of how this helps. I also know about
chaining GT(), LT(), etc, to form logical operations, but everything I can think
of would assign a new value at each timestep. I need more of a real
if(condition)-then(action), but I know these don't exist in trnsys. Any
thoughts?
Thanks,
Cramer
J. Cramer
Silkworth
Transsolar Climate
Engineering
Technical consulting for energy
efficiency and environmental quality in buildings.
145 Hudson
Street
Suite 402
New York, NY 10013
Office: 212-219-2255
Mobile: 347-283-2547
silkworth@transsolar.com
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