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Programming chapter 3 – Rockwell Automation 1772-AF1,D17726.5.1 User Manual MINI-PLC-2/15 User Manual

Page 39

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Programming

Chapter 3

3Ć31

Figure 3.27

General AF1 Deviation Function Format After Address Entry

17 16 15 14 13 12 11 10 7 6 5 4 3 2 1 0

S

Bit No.

Data Address

Digit 2

Digit 3

(LSD)

Input 1

S

Digit 2 Digit 3

Digit 2 Digit 3

Digit 1

S

Digit 1

(MSD)

Digit 2 Digit 3

Result Address

Digit 5

Digit 4

Result

D

E

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

11586

Digit 6

ER

ER = Error Bit (Set if number of readings = 0)

S

Digit 1

(MSD)

Digit 1

(LSD)

Input 2

Input 3

Number of Inputs

0

0

3

200

201

202

203

305

306

4. Enter the values of the numbers whose standard deviation is desired in the

input word addresses.

You can enter these numbers from the keyboard of your industrial terminal or
through ladder diagram functions. If we choose to enter values of 200, 201, and
202 into input word addresses 201, 202, and 203 respectively, we obtain the
result shown in Figure 3.28 when the standard deviation function executes. The
result appears in words 305 and 306 as 000.816. The result is truncated but is
accurate to +0.001.