Re: [foxboro] HLBL Array Question

Peter,

I tried the same thing as you a while back and was blown out of the =
water with cpu (IND) loading.  I wanted the value now (easy) and the =
value 15 minutes ago (no so easy).  So we looked at AIM since the =
historian was storing samples and the data was available.

We were going to write a C-program and use

call fh_RTP_Index to get the index number for the =
Compound:Block.Parameter

call fh_Fdb_GetValues  (histname, index, oldtime=3D0, numpts=3D1)

AIM returns latest value and current time (CTIM)

CTIM + 15 =3D NTIM

call fh_Fdb_GetValues  (histname, index, oldtime=3DNTIM, numpts=3D1)



Other projects took precedence and we never finished this so I cannot =
state that it worked.

I'm not sure what you ultimately want but there are ways to get data =
from the historian in a program and store it in a shared variable.

Hope this helps.


Terry Doucet



15 may 2008 14:46
 'Foxboro DCS Mail List' ('Foxboro DCS Mail List')
Objet=A0: [foxboro] HLBL Array Question

Gentlemen (and Ladies)

        I have a large array size is 1440 (holds 24 hours worth of 1 min =
sa=3D
mples)

        Every minute I want to update the 1 of the sample value and =
throw o=3D
ut the oldest value.

Problem 1)

        Currently I am shuffling each value 1 at a time using this loop:
----------------------------
      x :=3D3D 1;
      SN01 :=3D3D "Preparing Array for new value ....";
      WHILE (x < 1440) DO
        ARHR[x] :=3D3D ARHR[x+1]; {* throw out arry position 1 and =
shuffle *}
        x :=3D3D x + 1;
      ENDWHILE;
      ARHR[1440] :=3D3D RI01;     {* Load newest value into array =
position 14=3D
40 *}
------------------------------


        This works however just to shuffle the values takes almost 30 =
secon=3D
ds.

        Is there a quicker way to do this ?
      Is there a way to copy array position [2] through [1440] to =
another a=3D
rray using a single command ?

Problem 2)

        During the next step of my sequence I have to find the average =
for =3D
the last 24 hours so I need to find the sum of the array then divide by =
144=3D
0. I use the following loop to find the sum:

----------------------------
   y :=3D3D 1;
   SUM :=3D3D 0;
   WHILE ( y < 1441 ) DO
     SUM :=3D3D SUM + ARHR[ y ];
     y :=3D3D y + 1;
   ENDWHILE;
   RO01 :=3D3D SUM/1440; {* 24 Hour rolling average *}
----------------------------

        Again it takes about 30 seconds just to find the sum of the =
array.

        Is there a quicker way to find the sum of an array?


Thank You,

Peter Bruley



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