Rockwell Automation 1772-AF4,D17726.5.3 User Manual, AUX FUNCT PROM - Manual (Page 49)

Programming
Chapter 3
3Ć41
Figure 3.39
General AF4 Power Function Word and Digit Format
17 16 15 14 13 12 11 10 7 6 5 4 3 2 1 0
Digit 1
(MSD)
Digit 2
Bit No.
Data Address
m
Digit 2
Digit 2
Result Address
n D E
n + 1
E = Enable Bit (1 = Function in Progress)
D = Done Bit (1 = Function Complete)
MSD = Most Significant Digit
LSD = Least Significant Digit
11508
Digit 3
(LSD)
Digit 3 Digit 1
(MSD)
Digit 1 (MSD) Digit 3
(LSD)
S = Sign Bit (1 = Negative)
S
S
(LSD)
(Always = 0)
ER
Digit 1
(MSD)
Digit 2
Digit 3
(LSD)
S m + 1
Base y
Exponent x
Result Base, r
s (Power of 10)
ER = Error Bit (1 = Overflow when y > 9.99(10) ) x 099.
3. Enter a data address and a result address.
If we enter a data address of 200 and a result address of 300, the AF4
establishes the data table format shown in Figure 3.40. Word 200 is reserved
for the base y and word 201 is reserved for the exponent x. The result address,
word 300, is reserved for the result base r; word 301 contains the resultant
exponent s.
Figure 3.40
AF4 Power Function Format After Address Entry
17 16 15 14 13 12 11 10 7 6 5 4 3 2 1 0
Digit 1
(MSD)
Digit 2
Bit No.
Data Address
Digit 2
Digit 2
Result Address
D E
E = Enable Bit (1 = Function in Progress)
D = Done Bit (1 = Function Complete)
MSD = Most Significant Digit
LSD = Least Significant Digit
11509
Digit 3
(LSD)
Digit 3 Digit 1
(MSD)
Digit 1 (MSD) Digit 3
(LSD)
S = Sign Bit (1 = Negative)
S
S
(LSD)
(Always = 0)
ER
Digit 1
(MSD)
Digit 2
(LSD)
S
Base y
Exponent x
Result Base, r
s (Power of 10)
ER = Error Bit (1 = Overflow when y > 9.99(10) ) x 099.
200
201
300
301