Re: [foxboro] Running Average (was: foxboro Digest V7 #262)

How about this method using the standard blocks:
3 DTIME AND 3 CALC BLOCKS arranged as follows
All DTIME blocks have DTOPT = 0 to insure input averaging over the DT
period.  All blocks can run at perhaps 0.5 sec period. Number of BUCKETS is
8 to fit # inputs in the CALC or CALCA.

DTIME1
DT = 43200/8=5400  (# minutes in 30 days/8 buckets)
DTIME2
DT = 43200/8^2=675
DTIME3
DT = 43200/8^3=84.375

CALC1
ADD DTIME1.BKT_1 to BKT_7 +CALC2.RO01
OUT RO01 (30DAY AVE)
CALC2
ADD DTIME2.BKT_1 to BKT_7 +CALC3.RO01
OUT RO01
CALC3
ADD DTIME3.BKT_1 to BKT_8
OUT RO01
In this way the 30 day average will update stepwise about every 10.5 minutes
and the average will be done using every flow value (each 0.5 seconds) over
the 30 day period.  I.e. average of some 5,184,000 values.

Rick Rys
www.R2controls.com
1 Cherry Street
Mansfield, MA 02048
508-339-6633 Home Office
508-369-5186 Cellular



 
 
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