Programming
Chapter 3
330
Figure 3.26
General
AF1 Standard Deviation Function Word and Digit Format
171615141312111076543210
S
Digit 1
(MSD)
Digit 2
Digit 3
Bit No.
Data Address
Digit 2
Input 1
S
Digit 2 Digit 3
Digit 2 Digit 3Digit 1
S
Digit 1
(MSD)
Digit 2 Digit 3
Result Address
Digit 5Digit 4
Result
DE
E = Enable Bit (1 = Function in Progress)
S = Sign Bit (1= Negative)
D = Done Bit (1 = Function Complete)
MSD = Most Significant Digit
LSD = Least Significant Digit
11588
Digit 6
ER
ER = Error Bit (Set if number of readings = 0)
S
S
(LSD)
Digit 1
(LSD)
Input 2
Input 3
Input N
m
m + 1
m + 2
m + 3
m + N
n
n + 1
N = Number of Readings Whose Standard Deviation is Sought
Number of Inputs
Digit 1 Digit 3
Digit 2 Digit 3Digit 1
3. Enter a data address and store in that address the number of values whose
standard deviation you wish to determine.
Let’s choose a data address of 200 and the number of values whose standard
deviation we want of 003. Also, let’s choose 305 as our result address.
Entering these values results in the data table format shown in Figure 3.27.
once you enter the data address, the addresses of the remaining input words are
selected automatically by the AF1.
