In the previous lesson we discussed the Process Image Input or PII and its size. We wrote a simple move instruction to access an analog input only to find that just as soon as we downloaded it to the PLC, the PLC faulted and went into stop mode. In this lesson we will discuss the PII further and also troubleshoot our code to determine why our seemingly simple move instruction faults the PLC. It’s all about Peripheral Input addressing, why we need to do it and how it’s done. I’m sure you’re curious as to what’s going on so let’s get started with this lesson and cure your curious.