Jawaharlal Nehru Technological University Hyderabad B.Tech III Year INDUSTRIAL AUTOMATION Previous Question Paper (February - 2023 - R18)

An operating system (OS) is a system software that manages computer hardware, software resources, and provides common services for computer programs. It acts as an intermediary between the user and the computer hardware, controlling tasks such as memory management, process scheduling, file system organization, and peripheral device input/output operations.

I/O ports are the physical or logical interfaces that allow a programmable logic controller (PLC) or computer to communicate with external field devices. They serve as the bridge between the central processing unit and the industrial environment, enabling the exchange of data necessary for process control.

These ports are categorized into two main types:

• Digital I/O: These ports handle binary signals (on/off states), typically used for devices like push buttons, limit switches, and solenoid valves. They detect voltage levels to determine if a circuit is closed or open.
• Analog I/O: These ports handle continuous signals representing physical variables such as temperature, pressure, or flow rate. They use analog-to-digital (ADC) or digital-to-analog (DAC) converters to translate these variables into numerical values that the controller can process.

I/O ports are often organized into modules, providing isolation from high-voltage field devices and allowing for modular system expansion.