Correct Answer - Option 4 : Automation
Explanation
PLC: A PLC (Programmable Logic Controller) is an industrial computer control system that continuously monitors the state of input devices and makes decisions based upon a custom program to control the state of output devices.
Sequential Controller: A control system in which the individual steps are processed in a predetermined order, progression from one sequence step to the next being dependent on defined conditions being satisfied.
Microprocessor: A microprocessor is a multi-purpose, programmable clock-driven, register-based electronic device that reads binary instructions from a storage device called memory, accepts binary data as input, and processes data according to those instructions, and provide results as output.
The important point is- all the above three devices are electronic devices and don’t involve any mechanical action.
Automation, on other hand, is a technology that is mostly used to minimize human interaction (generally physical) with help of programming and computers. It involves the application of mechanical, electronics, and computer-based systems to control and operate the systems.
