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Result address – Rockwell Automation 1772-LS_LSP,D17726.8.6 PROG/OPER MANUAL-MINI PLC-2/05 User Manual

Page 96

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Math Instructions

Chapter 10

10Ć8

Figure 10.3

Result Address Format

X S Z o

M

L

K

X X X X

J

H

G

X X X X

F

E

D

X X X X

C

B

A

M

L

K

J

H

G F

E

D

C

B A

Operand A is displayed i the 1770ĆT3 industrial terminal like this:

N

N + 1

N + 2

N + 3

17 16 15 14

10 7

4 3

0

S = Sign Bit

X = Additional Storage Bits

13

u

o

u

= Overflow/Underflow

Z = Zero Indicator

Result Address

Result Address

The result address (term C) is the starting address of four consecutive data table
words that contain the:

sum
difference
product
quotient
root
converted

word

The result word has the format shown in Figure 10.3. The format is similar to
the data address except that there are three status bits.

Once you select the result address, the EAF instruction automatically reserves
the next three addresses for the remaining words of the result (Figure 10.3). Be
careful not to select data and result addresses so close together that the
addresses of the operands following the data address overlap the result address.

bit 17 - not used
bit 16 - sign bit: 0 = positive (+), 1 = negative (-)
bit 15 - zero indicator: 0 = non-zero; 1 = zero result