Some of the most often used instructions in PLC programming are comparator operations. In all of the previous PLC programs that we have worked with so far, we have mostly worked with bits. A bit has only two possible values of one or zero, true or false and based on these limited values you can easily demand the desired command for a PLC output. You don't need comparator operations when you're working with bits but in reality, in almost all projects, you'll have variables with integer and decimal values which are greater than bit values.

In this and next lessons, you're first going to become familiar with comparator operations and then you're going to learn how to use these instructions in your PLC program through a few practical programming examples.