Rockwell Automation 1772-AF1,D17726.5.1 User Manual MINI-PLC-2/15 - Manual (Page 20)

Programming
Chapter 3
3Ć12
3. Enter a data address and result address.
If we select a data address of 201 and a result address of 305, the AF1
establishes the data table format shown in Figure 3.7. The data address
eventually contains three digits of operand 1. The AF1 reserves the next three
higher addresses for digits 4 through 6 of operand 1, and digits 1 through 6 of
operand 2. The result address contains the most significant three digits of the
result and the next higher address contains the least significant three digits.
Figure 3.7
AF1 Subtraction Function Format After Address Entry
17 16 15 14 13 12 11 10 7 6 5 4 3 2 1 0
S
Digit 1
(MSD)
Digit 2 Digit 3
Bit No.
Data Address
Digit 5
Digit 6
Digit 4
(LSD)
Operand 1
S
Digit 1
(MSD)
Digit 2 Digit 3
Digit 5
Digit 6
Digit 4
(LSD)
Operand 2
S
Digit 1
(MSD)
Digit 2 Digit 3
Result Address
Digit 5
Digit 6
Digit 4
(LSD)
Result
D ER E
E = Enable Bit (1 = Function in Progress)
S = Sign Bit (1= Negative)
D = Done Bit (1 = Function Complete)
ER = Error Bit (1 = Overflow)
MSD = Most Significant Digit
LSD = Least Significant Digit
11485
201
202
203
204
305
306