All computer programming languages have logical expressions. A logical expression is typically an equation that evaluates to either 1 or 0, which represents true or false. IEC programming languages are no different, and each type of IEC language has its own method of creating logical expressions.
Each rung of Ladder Logic is an equation solved by the controller's Central Processing Unit (CPU) as True (1) or False (0), also known as Energized (1) or De-energized (0). Ladders are executed one rung at a time from top to bottom, and each rung executes one instruction (also known as an element in Logix) at a time from left to right.
The following diagram details the anatomy and terminology of a simple Ladder Logic program:
In the following sections, we will cover AND logic, OR logic, and NOT logic. As we will learn in the following sections, the AND, OR, and NOT logic instructions...
