Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 306)

Chapter 16
Instruction List Programming
16–2
Parallel Inputs
When the inputs are in parallel, the instruction list representation is as
follows:
a c
b
NEW RUNG
LD a
OR b
OUT c
Optimized
NEW RUNG
LD a
LD b
ORB
OUT c
Option 1
Parallel Input Branching
An input branch can be used to allow more than one combination of input
conditions on parallel branches. An example of this type of rung is shown
below.
a b d
c
NEW RUNG
LD a
AND b
OR c
OUT d
Optimized
NEW RUNG
LD a
LD b
ANB
OR c
OUT d
Option 1
NEW RUNG
LD a
LD b
ANB
LD c
ORB
OUT d
Option 2
Series Block Connection
When two blocks of instructions are connected in series, an ANB instruction
is used, as shown here:
NEW RUNG
LD a
OR b
LD c
LD d
ORB
ANB
OUT e NEW RUNG
LD a
LD b
ORB
LD c
LD d
ORB
ANB
OUT e
a e
b
c
d
NEW RUNG
LD a
OR b
LD c
OR d

ANB
OUT e
Optimized Option 1 Option 2


(See page 8–12 for more information regarding the use of the ANB
instruction.)