Control engineering: Basic terms explained

Back to basics tutorial: Understand the terminologies that comprise control engineering and what they mean for engineers.

By Mark T. Hoske and Kevin Parker October 6, 2019

Understanding basic terms helps when investing in processes and technologies related to control engineering and the design, integration, implementation, maintenance, and management control, automation, and instrumentation systems, components, and equipment.

Control systems

Control systems help factories produce quality goods safely and efficiently. Open-loop control includes a human. Closed-loop control is automated. A control loop involves a measurement (sensors), decision (logic device), and actuation (changes the process), which is repeated until optimized. Networks and software connect the three.

Programmable logic controllers (PLCs) and programmable automation controllers (PACs) are industrial computers to control production systems.

Edge computing and embedded systems control machines and processes and help humans make smarter decisions.

Dedicated controls or single-loop controllers make a specialized set of decisions about a control system.

Proportional, integral and derivative (PID) are process tuning parameters; advanced process control (APC) software improves decisions about processes.

Distributed control systems (DCS) and supervisory control and data acquisition (SCADA) are types of control systems.

Info management

Info management is the translation of data into information and its delivery to people who need it at the right times.

Human-machine interface (HMI) and operator interface (OI) help humans monitor, change, control and manage the state of a process.

Product lifecycle management (PLM) software evolved from computer-aided design. PLM can update information through a product’s life, aiding control design.

Manufacturing IT (information technology) and manufacturing execution systems (MES) improve production, and bridges production planning systems and the plant floor.

Industrial PCs (IPCs) are personal computers hardened for use in industrial environments.

IIoT, Industrie 4.0

Industrial Internet of Things (IIoT) and Industry 4.0: IIoT brings IT standards to industries. Industry 4.0 uses advanced technologies to make manufacturing smarter.

Mobility: Portable and handheld computers allow humans to make mobile decisions more quickly and efficiently and safely at an appropriate distance.

Asset management enables more effective maintenance on a wide range of devices and systems.

Virtualization, cloud, analytics: Virtualization segments computers. Cloud architectures run apps or storage separate from the source computer. Analytics software turns data into info.

Discrete manufacturing

Discrete manufacturing makes individual things of a certain number.

Mechatronics combines mechanical and electronic engineering.

Machine safety uses devices, systems, and procedures to lower risk to humans, equipment, and products in a production environment.

Motors and drives: Motors transform electrical and magnetic energy to motion. Drives control the motion of motors and other actuators.

Discrete sensors and machine vision: Discrete sensors measure presence, proximity, distance, vibration, direction, motion, and other parameters. Machine vision uses sensors and software to see.

Robotics: Industrial robotics use sensors, actuators, programming, and networks to perform dull, dirty and dangerous work with precision, repeatability and speed.

Computerized numerical control (CNC) and motion control: A CNC uses special computers and software to control and manage machine tools. Motion control decides movement.

Networking and security

Networking and security: Industrial networks runs software protocols over physical media to connect sensors, computers, actuators and systems. Security lowers industrial risk.

Cybersecurity uses technologies and procedures to protect devices, computers, systems and networks from unwanted intrusion.

Ethernet is an IEEE standard that defines communication protocol and medium. Ethernet has multiple standard variants for industrial networking of devices, computers and systems.

Wireless technologies and methods: Communicating though the air may enable lower-cost networking than wired connections. Many wireless standards serve various applications.

Other networks: Associations and manufacturers have created many sensor networks, device networks and computer networks for industrial communications.

Input and output (I/O) devices communicate measurements about the state of a process.

Process manufacturing

Process manufacturing makes (often fluid or gaseous) products in a continuous flow or batch process, of a certain amount.

Data acquisition (DAQ) can gather measurements that can be analyzed to help understand a process.

Simulators and optimizers use computer programs to improve processes without the commitment of physical resources.

Diagnostics and asset management: Diagnostics assess the current state of a process and may involve the identification of root causes. It helps with predictive maintenance of assets.

Process safety uses devices, systems, and procedures to lower risk to humans, process or batch equipment and products in a production environment.

Process sensors and actuators: Process sensors measure temperature, pressure, level, flow, and other parameters. Process actuators (valves, pumps, heaters, fans, mixers, and others) change a process.

System integration

System integration connects devices and systems, often with computers, software and networks, to optimize throughput.

System integrators for automation and controls design and integrate computerized control systems for industrial machines, manufacturers or facilities.

Project management: Work processes are often organized into projects that can be planned and coordinated.

Energy efficiency: Measuring and optimizing energy use is important in a time of constrained resources.

Energy and power are essential to all forms of work and require attention to technologies, safety, standards and best practices.

Workforce development teaches human resources with in-person or online training. Engineers require frequent training to remain useful and up to date in their professions.

Mark T. Hoske, content manager, Control Engineering,; Kevin Parker, content manager, Plant Engineering, CFE Media and Technology.

KEYWORDS: Control engineering, basic terms

Control engineering is more easily understood when related terms are defined.

Smart investments in control engineering processes and technologies help with optimization.

Efficiently integrating technologies helps.


Engineers often have multiple names for similar things. Has your organization agreed-upon terms to help new hires?

Author Bio: Mark T. Hoske, content manager, Control Engineering; Kevin Parker, content manager, Plant Engineering, CFE Media and Technology.