Especially in complex systems, there is never just one single level on which a process and its intermediate steps take place. In most cases, this process is divided into several levels, so that smooth communication between the components is required. This is made possible by so-called bus systems. Such a system bus is a summary of these buses, or data rails, which ensure within a microcomputer that the main processor (CPU for Central Processing Unit) can function with the remaining devices. Going back to the topic of the different levels, various regularities can be determined that illustrate how data exchange takes place within a pyramid and systems. One constant in particular can be determined, which at the same time also illustrates the problem: Between the different levels, which occur in the automation pyramid, the rule applies that the transmission speed becomes slower, the higher a level is, but in return the quantity of the data to be transmitted increases more and more. The different levels are are explained in the image.