Tag Archives: simple traffic light

PLC Fiddle Compare Challenge

Just about every program usually has some data comparison instruction. This is the ability to compare information from one area of the controller to another and act on results. The output of this comparison conditions the logical continuity of a rung. PLC Fiddle is a free online browser simulator and has the following compare contact instructions.
= (if Equal contact)
<> (if Not Equal contact)
> (if Greater Than contact)
>= (if Greater Than or Equal contact)
< (if Less Than contact)
<= (if Less Than or Equal contact)
We will be looking at these instructions along with some programming challenges. As a system integrator, this ability can prove very useful to you in the field when commissioning your automation system. We will look at these compare instructions and show the parameters required to program them. Our compare challenges will help you gain a good understanding of how we can use compare in the PLC. Trying these challenges with PLC Fiddle is fun and will help you with PLC programming. Let’s get started. Continue Reading!