SCADA glossary.
Plain-language definitions of the terms that matter — and how SCAIQ™ implements each concept.
SCADA
Supervisory Control and Data Acquisition — software that monitors and controls industrial processes by acquiring real-time data from field devices such as PLCs and RTUs.
SCAIQ™ is a browser-first SCADA platform built on this model.
HMI
Human-Machine Interface — the visualization layer operators use to observe and interact with an industrial process.
SCAIQ HMI delivers this experience entirely in the browser.
Historian
A system that records time-series process data for later analysis, trending, and reporting.
SCAIQ Historian provides buffered, configurable-retention time-series logging.
Tag
A named data point representing a single process value — a device measurement or a computed value.
SCAIQ Core maintains both device tags and expression (virtual) tags.
ISA 18.2
The ISA standard for management of alarm systems in the process industries, defining the alarm lifecycle from philosophy through rationalization, operation, and audit.
SCAIQ Alarms is built on the ISA 18.2 lifecycle model.
Alarm Rationalization
The documented process of reviewing and justifying each alarm's existence, priority, and response — recorded in a Master Alarm Database.
SCAIQ Alarms maintains rationalization records (cause, consequence, corrective action) per alarm.
Alarm Flood
A period during which the rate of incoming alarms exceeds an operator's ability to respond meaningfully — typically defined as more than 10 alarms in 10 minutes.
SCAIQ Alarms includes flood detection and process-state suppression to reduce floods at the source.
Chattering Alarm
An alarm that rapidly and repeatedly transitions between active and inactive states.
SCAIQ Alarms detects and flags chattering alarms for engineering attention.
Alarm Shelving
A timed, operator-initiated suspension of an alarm, with automatic return to active monitoring.
SCAIQ Alarms supports shelving with timed presets and auto-unshelve.
Modbus
A widely used industrial communication protocol for connecting PLCs, RTUs, and sensors, available in TCP (Ethernet) and RTU (serial) variants.
SCAIQ Connect includes Modbus TCP and RTU drivers.
OPC UA
Open Platform Communications Unified Architecture — a platform-independent, secure industrial interoperability standard.
OPC UA connectivity is part of the SCAIQ Connect protocol offering.
PLC
Programmable Logic Controller — an industrial computer that controls machinery and processes based on programmed logic.
SCAIQ Connect acquires data from and writes commands to PLCs across vendors.
RTU
Remote Terminal Unit — a field device that interfaces sensors and actuators to a SCADA system, often over wide-area or wireless links.
SCAIQ Connect and SCAIQ Edge support RTU-based remote acquisition.
Edge Computing
Processing data near its source — at the plant or site — rather than transmitting it all to a central system first.
SCAIQ Edge performs local collection and buffering before publishing to central or cloud SCAIQ™ deployments.
IIoT
Industrial Internet of Things — the use of connected sensors, devices, and analytics to improve industrial operations.
SCAIQ™'s architecture and Ath Software's IIoT delivery record (330+ meters at 2-second scan) both apply here.
RBAC
Role-Based Access Control — restricting system access based on a user's assigned role.
SCAIQ™ implements four cumulative roles: Operator, Supervisor, Engineer, Admin.
Audit Trail
A chronological record of system events and user actions, used for accountability and compliance.
SCAIQ™ audits logins, security events, page access, and every operator action.
Digital Twin
A virtual representation of a physical asset or process, used for simulation, monitoring, or optimization.
Ath Software's Virtual Process Plant delivery reflects this domain — discuss current platform fit with our engineers.
See SCAIQ™ live.
Bring your toughest SCADA questions. Our engineers will show you real screens, real alarms, and real trends.
Or talk to us directly: +91 84014 22388 ·sales@scaiq.com