Allen-Bradley Logix5000 Reference Manual page 392

Chapter 8 Array (File)/Misc. Instructions (FAL, FSC, COP, CPS, FLL, AVE, SRT, STD, SIZE)
Description:
392
The standard deviation is calculated according to this formula:
Standard Deviation =
Where:
· start = dimension-to-vary subscript of the array operand
· x
= variable element in the array
i
· N = number of specified elements in the array
· AVE =





i
---------------------------------------- -
IMPORTANT
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011

N


[ 
X

(
start +

i = 1
------------------------------------------------------------------- -
(
N 1 –
N


x

( )
start + i

= 1
N
Make sure the length does not cause the instruction to
exceed the specified dimension to vary. If this happens, the
destination will be incorrect.


2
 ]
– AVE

)
i

)