Re: [TRNSYS-users] Raising flags

Hi Stefan,

Here’s a trick to hold a value for a given duration (just set the value of the variable ‘Duration’ in the macro to 8760 if you want to keep it forever).

HTH,

Werner

De : Stefan de Kool [mailto:S.deKool@chri.nl]
Envoyé : jeudi 25 octobre 2007 09:43
À : trnsys-users@engr.wisc.edu
Objet : Re: [TRNSYS-users] Raising flags

Dear Karl,

Thanks for the idea. The problem is though that as soon as Tin gets less than Tset again, it ‘looses’ its value. What i want is to keep it at Tset untill another condition is met, but not when Tin<Tset. In fact i want to include some form of hysteresis in a control loop.

(PS: you can use GE instead of combining GT and EQL)

Kind regards

Stefan

Van: Karl Vonderputten [mailto:karl@chromagen.com.au]
Verzonden: woensdag 24 oktober 2007 23:27
Aan: Stefan de Kool
Onderwerp: RE: [TRNSYS-users] Raising flags

Hello Mr De kool

You could try the following to raise a flag

Eqns 3

Tset = 60 ! Tset whatever set point

Tin = [9,6] ! Whatever output from whatever control card

Tout = Tset*GT(Tin, Tset)+ Tset*EQL(Tin, Tset) + Tin * LT( Tin, Tset)

I included the _expression_ in the middle because I was not sure what the equation would do if the

Value Tin was ever exactly equal to Tset. It may not be necessary

Please let me know if this was helpful

(I may like to use it later myself)

Regards

Karl Von Der Putten

From: Stefan de Kool [mailto:S.deKool@chri.nl]
Sent: Thursday, 25 October 2007 1:03 AM
To: trnsys-users@engr.wisc.edu
Subject: [TRNSYS-users] Raising flags

Dear all,

Does anyone know if there is a way to ‘raise flags’ in trnsys? I want to give a certain variable a value at the moment a certain temperature is reached and to keep that variable at that value regardless of further temperature changes.

Regards,

Stefan de Kool

Cauberg-Huygen Raadgevende Ingenieurs B.V.

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