RE: Type 9

[Michaël Kummert <kummert@xxxxxxxxxxxxx>]

Dear Stefano, 

Type 9 can read data with any time step that is acceptable for TRNSYS.

TRNSYS 15 accepts time steps down to 0.001 h (3.6 sec). The time step must
satisfy the following requirements:
- If it is less than 0.02, it must be the 
  reciprocal of an integer smaller than 1000.
- If it is greater than 0.02, it must be the ratio
  of two integers (with a denominator <= 50)
Note that the current TRNSYS release (15.3.00) rounds the time step to the
nearest value which matches those criteria if necessary. In this case, a
warning is issued.

You example, 10 sec, is 1/360 hour so it is OK (it would not be rounded). 

Here are a few examples of time steps and what TRNSYS would do with them:

dt[sec]  | dt [h]     | rounded to (fraction) 
---------------------------------------------
    1.00 | 0.00027778 | 0.00100000  (1/1000)
 anything < 3.6 sec   | 0.00100000  (1/1000)
    3.60 | 0.00100000 | Not rounded (1/1000)
   10.00 | 0.00277778 | Not rounded (1/360)
   30.00 | 0.00833333 | Not rounded (1/120)
   60.00 | 0.01666667 | Not rounded (1/60)
   77.00 | 0.02138889 | 0.02127660  (1/47)
  120.00 | 0.03333333 | Not rounded (1/30)
  145.00 | 0.04027778 | 0.04000000  (1/25)
  300.00 | 0.08333333 | Not rounded (1/12)

I hope this helps,

Michaël Kummert
_________________________________________________________

Michaël Kummert

Solar Energy Laboratory - University of Wisconsin-Madison
1303 Engr Res Bldg, 1500 Engineering Drive
Madison, WI 53706

Tel: +1 (608) 263-1589
Fax: +1 (608) 262-8464
E-mail: kummert@engr.wisc.edu

SEL Web Site: http://sel.me.wisc.edu 
TRNSYS Web Site: http://sel.me.wisc.edu/trnsys


> -----Original Message-----
> From: owner-trnsys@relay.doit.wisc.edu 
> [mailto:owner-trnsys@relay.doit.wisc.edu] On Behalf Of 
> Stefano.Esposto@uniroma1.it
> Sent: Thursday, May 22, 2003 08:48
> To: trnsys@relay.doit.wisc.edu
> Subject: Type 9
> 
> 
> Dear TRNSYS users,
> I've a question about the data readable by the type 9. I've 
> seen that it's possible to read for a trnsys simulation 
> weather data recorded hourly o daily.Is it possible to read 
> datas recorded with lower interval of time (for example 
> minutes or seconds)?. I'm asking this because I've the 
> possibility to have data recorded by our weather station each 
> second, and I would like to make simulation in ISIBAT using 
> these datas for short simulation (3-4 hours with a simulation 
> time step of 10 seconds). Thank you
> 
> Regards
> 
> Stefano Esposto
>