Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 307)

Chapter 16
Instruction List Programming
16–3
Parallel Block Connection
If two blocks of instructions are connected in parallel, an ORB instruction is
used. An example of this type of block connection is provided below.
NEW RUNG
LD a
LD b
ANB
LD c
AND d
ORB
OUT e NEW RUNG
LD a
LD b
ANB
LD c
LD d
ANB
ORB
OUT e
a b e
c d
NEW RUNG
LD a
AND b
LD c
AND d

ORB
OUT e
Optimized Option 1 Option 2



(See page 8–12 for more information regarding the use of the ORB
instruction.)
Nested Input Branching
You can nest input branches to avoid using redundant instructions. This
example shows how ANB and ORB instructions are used together in these
type of rungs. (See page 8–12 for more information regarding the use of
these instructions.)
NEW RUNG
LD a
LD b
ANB
LD c
LD d
LD e
AND f
ORB
ANB
AND g
ORB
OUT h NEW RUNG
LD a
LD b
ANB
LD c
LD d
LD e
LD f
ANB
ORB
ANB
LD g
ANB
ORB
OUT h
a b h
c d g
e f
NEW RUNG
LD a
AND b
LD c
LD d
LD e
AND f

ORB
 ANB
AND g
 ORB
OUT h
Optimized Option 1 Option 2