1. Project architecture

A project is made up of configurations. A configuration is a hardware platform comprising one or more resources. A resource represents a virtual machine. A resource is divided into several programming units called POUs (program organization units). The POUs of a resource are organized in a hierarchical architecture. POUs can be described using the graphical or textual languages SFC, FC, ST, IL, FBD or LD. POUs can be programs, functions or function blocks.