In this lesson we are going to discuss logic gates. If you don’t know how logic gates work, watching this lesson will explain that for you. If you are familiar logic gates, we will run through a quick refresher explaining the four types of gates. Those types are AND, OR, XOR or Exclusive OR, and INVERT or NOT. This lesson will show you exactly how the logic gates work by demonstrating in ladder logic. While this ladder logic does not use the actual gate instruction, it does show the function of the gate through the use of contacts and coils. In the next lesson, we will use the actual instructions but for now, let’s take a look at this lesson and get a refresher on logic gates.