Re: [foxboro] 12 hour ave

At 05:54 PM 2/25/04 -0600, Brian Long wrote:

 >I need to take an analog input running at 1 sec and average it over
 >12 hours.  I need to display the value so I can't use the historian
 >functions. Anybody got a simple solution?

Just thinking out loud here....

Feed the measurement into an ACCUM block, then every 12 hours, average 
the accumulated value before your CLEAR the block.

I have a shell script which is scheduled through cron to clear an ACCUM 
block, and you can average your value there too, but then you have 
omset it to some comp:block.param from the script file.

Or using another tack, you can count time with a CALC block and when 
(12 hrs * 60 minutes * 60 seconds) has elapsed, average the accumulated 
value and output it to a RIxx, and clear the ACCUM block.

Of course all these methods give you only one average value every 12 
hours. If you want running average, you'll have to do something else.

Duc

 
 
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