PLC Logic Question (Logix Studio 5000)

This clip explains some interesting issues with PLC logic. 

Many times people assume the processor analyzes all logic and somehow knows what we are trying to tell it to do - when in reality it only executes the code it is given. So - it is important to understand the order of execution of the processor in order to write proper logic and to interpret that logic. 

In the video, I explain the issue of scan cycle with OTL and OTU instructions and also cover some other common misconceptions (power flow indication confusion specifically among others).