Industrial automation glossary

Alarm flood

A situation in which more alarms arrive in a short time than an operator can process.

Alarm management

The discipline of designing, monitoring and improving alarms by purpose, response and priority (ISA-18.2, IEC 62682).

It rests on the principle that every alarm must require an operator action; nuisance alarms raise operator workload and risk.

Brownfield

An operating plant that is being upgraded or extended.

Commissioning

Bringing a system into working order on site after installation and verifying it.

Cut-over

The planned moment at which production moves from the old control system to the new one.

A cut-over is not made until the rollback plan and FAT results are ready.

DCS

Distributed control system: controllers, I/O, network and operator stations engineered as one platform for continuous process control.

A distributed control system (DCS) is used in continuous-process plants such as power, cement, paper, petrochemicals and water. Control logic, alarms, history and operator graphics share one data model, which keeps hundreds or thousands of signals consistent to operate.

ERP

Enterprise resource planning: manages finance, purchasing, inventory and production planning.

FAT

Factory acceptance test: verifying the system against the specification in a controlled setting before it ships.

FAT usually exercises logic, graphics and alarms with simulated I/O; open items are recorded and closed.

Historian

A database that stores and queries process data as high-rate time series.

The historian is the core data source for trend analysis, reporting and post-event investigation.

HMI

Human-machine interface: the screens where operators monitor and act on a process: graphics, alarms and trends.

A good HMI directs operator attention to abnormal situations; consistent page standards and alarm prioritization are its foundation.

I/O list

The project document that defines every field signal: tag, type, range and alarm limits.

The I/O list is the shared basis for controller configuration, HMI tags, FAT and loop checks. Managed as a single revisioned source, it removes a whole class of engineering errors.

IEC 61131-3

The standard that defines PLC programming languages: LD, FBD, ST and SFC.

IEC 62443

The standard series that defines cybersecurity for industrial automation and control systems.

IIoT

Industrial Internet of Things: carrying field-device data to cloud and analytics systems.

Kepware

The industrial connectivity platform that translates many device protocols into open standards such as OPC UA.

ASP Otomasyon is the authorized distributor of Kepware products in Turkey.

Loop check

Verifying the complete path of a signal from the field device to the controller and the operator display.

Loop checks are among the most labour-intensive commissioning steps; a sound I/O list and test forms shorten them.

MES

Manufacturing execution system: manages production orders, traceability and production performance.

The MES sits between the control system and ERP; it needs correct timestamps and quality information to rely on plant data.

MQTT

A lightweight publish/subscribe messaging protocol.

OPC DA

The classic COM/DCOM-based OPC data access interface.

OPC DA is Windows-specific and has limited cross-machine security, which is why existing systems plan a move to OPC UA.

OPC Router

Integration software that models bidirectional data flows between OT and IT systems (SAP, SQL, MQTT, REST) visually.

OPC UA

The platform-independent industrial interoperability standard with certificate-based security (IEC 62541).

OPC UA carries data together with an information model and is not tied to Windows. It is preferred over OPC DA for new projects.

OT

Operational technology: the hardware and software that monitors and controls physical processes.

In OT networks availability and safety rank differently than in IT networks.

P&ID

Piping and instrumentation diagram: the drawing of a process’s equipment, lines and instruments.

The P&ID is the starting point of control engineering; the I/O list and control strategies are derived from it.

PLC

Programmable logic controller: a rugged controller that reads field inputs and drives outputs in a repeating scan cycle.

PLCs are common in machine automation and discrete processes and are also used for small and mid-size process units. Their programming languages are defined by IEC 61131-3.

Purdue model

A reference model that arranges industrial control networks into levels from field devices up to enterprise systems.

Data flows between levels are designed deliberately through firewalls and a DMZ.

Redundancy

Paired components that keep the system running when one of them fails.

Redundancy is planned separately for controllers, networks and servers. Redundancy, backup and buffering are different things.

SAT

Site acceptance test: verifying the system on site with real instruments, valves and process.

SAT proves what FAT cannot: field wiring, real measurement ranges and process dynamics.

SCADA

Supervisory control and data acquisition: software that collects data from controllers, shows it to operators and keeps history.

SCADA is typically used to supervise geographically spread assets such as pump stations or substations. Our article “SCADA vs. DCS” covers the difference in detail.

Setpoint

The target process value a control loop is asked to reach.