Topic
ISA
19 guides across the knowledge base.
ISA-101: Human Machine Interfaces
What the ISA-101 standard for human machine interfaces covers, its lifecycle from philosophy to maintenance, the display hierarchy, and what adopting it changes on a project.
8 min readUpdated Sep 5, 2026
The Alarm Philosophy
The document that decides what is allowed to be an alarm: the definition, the criteria, the priorities and their meaning, the performance targets, the handling rules, and who owns it. Under ISA-18.2 it comes first.
9 min readUpdated Sep 5, 2026
Alarm Priority
How to assign alarm priorities that operators trust: a consequence-and-time matrix, three or four levels, the target distribution from ISA-18.2 and EEMUA 191, and the mistakes that make every alarm high.
9 min readUpdated Sep 5, 2026
Alarm Rationalization
The meeting where every alarm earns its place: who attends, what is decided for each alarm, how to document it in a master alarm database, and how to run it at a utility that cannot spare a week.
10 min readUpdated Sep 5, 2026
Alarm Floods
What an alarm flood is, why it happens at exactly the wrong moment, the ISA-18.2 rate targets, and the design measures that keep a power failure or a communication loss from burying the one alarm that matters.
10 min readUpdated Sep 5, 2026
HMI Faceplates
The pop-up that controls one device: what a pump, valve, or loop faceplate must show, the mode and command layout, interlock and permissive display, security by role, and building faceplates from a standard object so every device behaves the same.
10 min readUpdated Sep 5, 2026
Alarm Indication on the HMI
How an alarm looks and sounds on the operator screen: the ISA-101 and ISA-18.2 rules for color, shape, and blink, the alarm banner and summary, acknowledgment behavior, navigation to the alarm, and indication that survives colorblindness and a noisy control room.
10 min readUpdated Sep 5, 2026
HMI Navigation
How operators move through the displays: the display hierarchy from overview to detail, a fixed navigation bar with area alarm indication, one-click paths from an alarm to the device, the rules that keep any display within two clicks, and what to leave out.
9 min readUpdated Sep 5, 2026
Alarm Servers
The part of SCADA that turns a condition into an alarm and manages its life: where detection happens, the alarm state machine, priority, deadband and delays, acknowledgment across clients, the journal, notification, redundancy, timestamps, and flood behavior.
10 min readUpdated Sep 5, 2026
Color in HMI Design
How color is used on a high performance HMI: a gray palette for normal operation so that color means something, alarm colors reserved by priority, equipment state by fill and text rather than red and green, color-blind safe choices, and the palette table.
9 min readUpdated Sep 5, 2026
Situational Awareness
Designing displays so an operator knows what is happening, what it means, and what comes next: the three levels of awareness, the display hierarchy, analog indicators with normal ranges, embedded trends, time-to-limit predictions, and a test for any display.
10 min readUpdated Sep 5, 2026
Alarm Shelving
The operator tool for temporarily silencing a nuisance alarm: what shelving is and is not, the rules a philosophy sets, who may shelve what and for how long, automatic unshelving, the shelved list, the record, and how to implement it on any platform.
8 min readUpdated Sep 5, 2026
Alarm Suppression
Suppressing alarms by design: state-based logic that removes alarms that mean nothing in the current state, parent-child logic that stops a flood at its source, out-of-service suppression for maintenance, the rules that keep it safe, and how to test it.
9 min readUpdated Sep 5, 2026
Alarm Problems
How an alarm system fails: alarms that never raise, raise unheard, stick, chatter, or flood, acknowledgments that do not propagate, and notifications that never arrive, with the causes by layer and the end-to-end test that proves the whole chain.
9 min readUpdated Sep 5, 2026
IEC 62443
The international standard series for industrial automation and control system security: how it is organized, what security levels and foundational requirements mean, and how a utility or integrator actually uses it.
11 min readUpdated Sep 5, 2026
How to Read a P&ID
What a piping and instrumentation diagram shows, how ISA-5.1 tag bubbles and line types encode the control system, and how to trace a loop across sheets.
8 min readUpdated Sep 5, 2026
ISA Standards for Controls
The International Society of Automation standards a controls practitioner meets: ISA-5.1 symbols and tags, ISA-18.2 alarm management, ISA-101 HMI design, ISA-88 and ISA-95 for batch and enterprise integration, ISA-99 which became IEC 62443, ISA-20 specification forms, and how each is used on a water or wastewater project.
8 min readUpdated Sep 5, 2026
ISA-18.2 Alarm Management
The lifecycle standard for alarm systems, the rate targets that define a workable system, and why alarm rationalization is the step nobody wants to fund.
10 min readUpdated Aug 15, 2026
High Performance HMI Design
Grey backgrounds, reserved color, and displays designed to make abnormal conditions obvious rather than to look impressive in a demo.
8 min readUpdated Jul 24, 2026
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