Re: [foxboro] Follow-up ACCUM reset and Question

Brian, I have had good results with using the "TIM" function within a
calc block.
Here I use the first pulsed output to trigger "mailbox" blocks to store
the accumulated total, then the second pulse  actually resets the
accumulators.
I'm sure this is not the most elegant way to do this, but I have
utilized this for many years.



Here are the steps I am using:
NOTE RI02: contains 86370.00000 - this causes the reset to occur 30
seconds before midnight


 
STEP01  TIM ; TIME IN SECONDS SINCE MIDNIGHT
STEP02  IN RI02 ; RESET TIME IN SECONDS 
STEP03  SUB
STEP04  OUT RO01 ; TIME LEFT TO RESET IN SECONDS
STEP05  BIN 9 ;  JUMP IF IT IS NOT TIME TO RESET
STEP06  IN 1 ; IF IT IS RESET TIME DO THIS 
STEP07  STM M01   
STEP08  GTO 11; 
STEP09  IN 0 ; NO RESET
STEP10  STM M01
STEP11  LAC M01
STEP12  OUT BO01 ; RESET NOTIFICATION  - in your case, this could be the
only thing you utilize
STEP13  OSP 4 ; LENGTH OF MAILBOX PULSE
STEP14  OUT BO02 ; LOAD MAILBOX PULSE
STEP16  DOFF 2 ; DELAY BETWEEN MAILBOX AND CLEAR PULSE
STEP17  NOT
STEP18  OSP 4 ; LENGTH OF CLEAR PULSE
STEP19  OUT  BO03 ; CLEAR ACCUMS
STEP20  END

Have fun with it.

Sean Meltvedt
Flint Hills Resources Alaska LLC






-----Original Message-----
From: foxboro-bounce@xxxxxxxxxxxxx [mailto:foxboro-bounce@xxxxxxxxxxxxx]
On Behalf Of BrianLong
Sent: Thursday, February 19, 2009 9:26 AM
To: Foxboro
Subject: [foxboro] Follow-up ACCUM reset and Question

The original problem was trying to get an ACCUM block in two different
CP's to reset at the same time.  In our case setting the ACCUM blocks as
the first block in the compund in each CP and using the same calc block
for the reset seemed to take care if it.  There is about a 1 second
difference now.
 
New question, we're using a CALC block to reset the ACCUM blocks using
xxCPxx_STA:STATION.HOUR and .MINUTE parameters.  The reset is set to
occur at 23:58, looking a values in the historian the reset will occur
anywhere between 23:58:08 and 23:58:16.  This is not an issue but I was
curious why it takes that long to process?
 
Thanks,
Brian Long
Arkansas Kraft    

 
 
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