3. Special functions

These are functions that go beyond Boolean processing, and are linked to a specific sector of activity (e.g. control, machine vision), hence the name "business functions". At a minimum, they take the form of function blocks in FBD language, sometimes in the form of programs, procedures and even processing languages, and sometimes in the form of specific modules in boxes or boards. These modules not only provide a link with the outside world, but also take on part of the processing, thus relieving the load on the processor and improving performance. To do this, they need to include a specific processor or specialized wired electronics.