Concept 01 – Original automation structure: HMI – Central PLC – Control wiring
This structure is found in many applications and is based on a
central PLC that controls the machine. However, this automation
structure is very personnel and work intensive: A production
manager on site reads the production data at the machine, and a
machine operator and mechanic are also required. The mechanic
has to refit the entire machine when a new recipe is required.
These systems typically involve the use of mechanical gears,
cams that are controlled with a main drive – all these configured
for a unique production task. As soon as production has to be
changed, the machine is retrofitted in one or two days, after
which it can be restarted. The PLC often involves complex local
wiring systems: wiring systems in the junction box, sensors on
the machine and also safety wiring connected in parallel.