Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 173)

Chapter 10
Using Math Instructions
10–7
Ladder Rung
(U)
S:5
0
] [
B3
0
[OSR]
B3
1
When the rung goes true for
a single scan, B1 is added
to B2. The result is placed
in B2.
SUB
SUBTRACT
Source A
B3:3
0000000000000011
Source B 1
Dest B3:3
0000000000000011
ADD
ADD
Source A
B3:1
0101010110101000
Source B B3:2
0001100101000000
Dest B3:2
0001100101000000
ADD
ADD
Source A
1
Source B B3:3
0000000000000011
Dest B3:3
0000000000000011
] [
S:0
0
] [
B3
31
If a carry is generated (S0/0
set), 1 is added to B3.
If B1 is negative (B/31 set),
1 is subtracted from B3.
Overflow trap bit S5/0 is
unlatched to prevent a major
error from occurring at the
end of the scan.
Instruction List
FUN GRAPHIC PARAMETER
CODE SYMBOL MNEMONIC NAME ADDRESS VALUE FORCES
–––– ––––––– –––––––– –––– ––––––– ––––– ––––––
20 |–] [– LD B/0 0
29 –OSR– AND–OSR B/1 0
80 ADD SRCA B1 0101010110101000
SRCB B2 1940H
DEST B2 1940H
10 MPS
22 –] [– AND S0/0 0
80 ADD SRCA 1
SRCB B3 0003H
DEST B3 0003H
11 MRD
22 –] [– AND B/31 0
81 SUB SRCA B3 0003H
SRCB 1
DEST B3 0003H
12 MPP
42 –(U)– RST S5/0 0