[foxboro] RE : LLAG Block
- From: "Doucet, Terrence" <tdoucet@xxxxxxxxxxxxxxxxxx>
- To: <foxboro@xxxxxxxxxxxxx>
- Date: Wed, 4 Jul 2007 12:53:45 -0400
Mark,
Just so we don't leave you hanging I will make a few statements which hopefuly
you do not already know.
1. I really don't know the specific Foxboro answer. The EDOC shows the complex
equation used when this form is enabled and it would probably take me two days
to resolve for " y " unless I could find a recent graduate who remembers how to
do all that stuff.
2. The standard lead-lag block uses LAGTIM that specifies the time constant for
a "first order" lag.
3. A quadratic equation is one that uses a higher power (you know, like George
Bush) perhaps squared or fourth power or something else. The LAG2 operation
seems to cause the output to take a different form than first order lag and
that varrying the parameters can change the shape of the response.
4. My last recollection of using such equations was for open flow measurement
such as on river flood water.
Hope this helps.
Terry
________________________________
De: foxboro-bounce@xxxxxxxxxxxxx de la part de Clement, Mark (Kiddmetallurgical
- Copper)
Date: mer. 2007-07-04 07:15
À: 'foxboro@xxxxxxxxxxxxx'
Objet : Re: [foxboro] LLAG Block
Trying this again
-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx
[mailto:foxboro-bounce@xxxxxxxxxxxxx]On Behalf Of Clement, Mark
(Kiddmetallurgical - Copper)
Sent: Friday, June 29, 2007 1:35 PM
To: 'foxboro@xxxxxxxxxxxxx'
Subject: [foxboro] LLAG Block
Hi All,
Has anyone ever run across documentation on how the LAG2 parameter works
with the LLAG block ?
Specifically interested in knowing what "quadratic lag time " is and how it
could be used
Thanks in advance
Regards
Mark
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