Now that you know how a single rung is executed, and how its results are stored in memory, you should be ready to learn about how a PLC executes a program as a whole.
As discussed in previous videos, the PLC executes rungs in order from top to bottom, and each rung is evaluated from left to right.
However, what happens when the PLC gets to the end of the program? The answer: It starts over from the beginning!
A PLC program is executed similarly to how an infinite loop in a typical programming language is executed.
As you now know, the behavior of a basic PLC program is very straight-forward. However, you might be wondering how this translates to the control of real-world devices.
In the CompactLogix and ControlLogix line of Allen-Bradley PLCs, “Controller Tags” are automatically generated for all the av...
As you may know, we have created hundreds of very informative lessons on PLC programming.
We have worked in the Step7, TIA Portal and Factory I/O software environments.
In this lesson, we are going to not only introduce a new PLC but also a new PLC programming environment.
Allen Bradley...
In this lesson, we continue where we left off in the lesson titled: An Introduction to Allen Bradley Using Studio 5000 Logix Developer.
That lesson had us launching software, opening the create dialog and making some selections that created our base project.
We’ll start by opening and rev...
