Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 108)

Chapter 6
Programming Overview
6–11
When entering hexadecimal characters, you may need to access the following
additional characters, not displayed on the keypad.
To Access This
Character:
Press This Key
Sequence:
A FUN
7
B FUN
8
C
9
FUN
D FUN
4
E FUN
5
F FUN
6
You can change the radix for output, input, bit and integer data files. See
page 18–30 for more information.
The program is made from the logic you enter into the micro controller.
Ladder logic instruction programming, which you may already be familiar
with, is one method used to enter logic. Another method is called Instruction
List (Boolean) programming. Your MicroLogix 1000 HHP uses this type of
logic programming. An overview of ladder logic and instruction list
programming is provided below.
Understanding Ladder Logic Instruction Programs
Ladder logic is a graphical programming language based on electrical relay
diagrams. Instead of having electrical rung continuity, ladder logic is
looking for logical rung continuity. A ladder diagram identifies each of the
elements in an electromechanical circuit and represents them graphically.
This allows you to see how your control circuit operates before you actually
start the physical operation of your system.
1
]/[
I
] [ ( )
O
1
I
input instructions output instruction
0
Applying Logic to Your
Schematics