PLC is A programmable logic controller (PLC) is a digital computer applied for
the automation of electromechanical processes. Almost any production line,
machine function, or process can be greatly enhanced using this type of
control system. It continuously monitors the state of input devices and makes
decisions based upon a custom program to control the state of output devices.
PLCs are demanded to work flawlessly for years in industrial environments
that are hazardous to the electronic components that modern PLCs are made
from. PLCs must be robust and designed for immunity to electrical noise,
resistance to vibration, impact, extended temperature ranges and moisture.
A PLC is a hard real-time system. Output must be produced in response to
input conditions within a limited time. Otherwise, an unintended operation
will result. It can cause many damages