Re: [foxboro] Rate of Change Alarming
- From: "Ron Schafer" <rschafer@xxxxxxxxxxxxxxxxxxxxxx>
- To: <foxboro@xxxxxxxxxxxxx>
- Date: Mon, 7 May 2007 12:24:09 -0400
You might also consider Calca/Calc blocks and using the memory address
and the avg function to do that. Here is code for a one hour sliding
window using 20 samples at 3 minute intervals.
Note that the RI001 & RI002 values are used to establish the reset value
and decrement amount. The period is one minute. Maybe someone knows a
way to get a better resolution for something like this? You should be
able to connect this to your ROC value and make it work as your 5 min
avg and possible manipulate it to trigger ROC alarming.
NAME =3D LINE3:37WY2307
TYPE =3D CALC
DESCRP =3D 1 HOUR SLIDING WINDOW
PERIOD =3D 6
PHASE =3D 0
LOOPID =3D=20
RI01 =3D :37JI2307.PNT
HSCI1 =3D 10000
LSCI1 =3D 0.0
DELTI1 =3D 1.0
EI1 =3D KW
RI02 =3D 2.0
HSCI2 =3D 100.0
LSCI2 =3D 0.0
DELTI2 =3D 1.0
EI2 =3D %
RI03 =3D 1.0
HSCI3 =3D 100.0
LSCI3 =3D 0.0
DELTI3 =3D 1.0
EI3 =3D %
STEP01 =3D IN RO02
STEP02 =3D BIP 48
STEP03 =3D CST
STEP04 =3D IN M19
STEP05 =3D STM M20
STEP06 =3D IN M18
STEP07 =3D STM M19
STEP08 =3D IN M17
STEP09 =3D STM M18
STEP10 =3D IN M16
STEP11 =3D STM M17
STEP12 =3D IN M15
STEP13 =3D STM M16
STEP14 =3D IN M14
STEP15 =3D STM M15
STEP16 =3D IN M13
STEP17 =3D STM M14
STEP18 =3D IN M12
STEP19 =3D STM M13
STEP20 =3D IN M11
STEP21 =3D STM M12
STEP22 =3D IN M10
STEP23 =3D STM M11
STEP24 =3D IN M09
STEP25 =3D STM M10
STEP26 =3D IN M08
STEP27 =3D STM M09
STEP28 =3D IN M07
STEP29 =3D STM M08
STEP30 =3D IN M06
STEP31 =3D STM M07
STEP32 =3D IN M05
STEP33 =3D STM M06
STEP34 =3D IN M04
STEP35 =3D STM M05
STEP36 =3D IN M03
STEP37 =3D STM M04
STEP38 =3D IN M02
STEP39 =3D STM M03
STEP40 =3D IN M01
STEP41 =3D STM M02
STEP42 =3D IN RI01
STEP43 =3D STM M01
STEP44 =3D AVE
STEP45 =3D OUT RO01
STEP46 =3D IN RI02
STEP47 =3D OUT RO02
STEP48 =3D SUB RI03 RO02
STEP49 =3D OUT RO02
STEP50 =3D EXIT
END
Ronald G. Schafer
10026 Old Ridge Rd.
Ashland Va. 23009
804-227-4034
-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx]
On Behalf Of Jaudon, Mike
Sent: Monday, May 07, 2007 11:22 AM
To: foxboro@xxxxxxxxxxxxx
Subject: Re: [foxboro] Rate of Change Alarming
Thanks to Leonardo (DiCapro) Moramarco and Brad Wilson (Pickett) for
your help but there is just one little hiccup I have to work out.
With the 500 DegF in 5 min ROC alarm (1.67 DegF/Min) and the parameters
you guys suggested it worked perfectly (I got the alarm after 5 minutes)
with one exception.
If at any point the ROC dropped below 1.67 (say for 10 seconds at the 2
minute mark) but increased back up and above the 1.67 (from the 2 minute
mark through the 5 minute mark) it would not give an alarm. It did give
the alarm later, however (at the 7 minute and 10 second mark).
It looks that the rate must be above the 1.67 for 5 consecutive minutes
for the alarm to generate whereas I what I want is "the average ROC of
1.67 for 5 minutes" then generate an alarm.
Corey Clingo mentioned a DTIME block and I believe it will do the
(weighted) average of a measurement over time. I will see if I can get
this to work.
Thanks to all for your help.
Michael L. Jaudon
TRONOX, LLC
(Technology Group-Hamilton, MS)
(662)343-8710 Office
(662)304-0313 Cell
mike.jaudon@xxxxxxxxxx
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