A Human Machine Interface is the operator's window into the plant. When it is designed well, an abnormal situation is obvious within seconds; when it is designed poorly, critical information hides behind clutter, colour noise, and inconsistent navigation. At ATAS, HMI design and development is a core part of our SCADA system engineering scope, and we treat it as an engineering deliverable — not decoration.
Start from the process, not the screen
Every HMI project begins with the P&ID, the cause & effect matrix, and a conversation with the people who will run the plant. From these we derive a display hierarchy: overview pages for situational awareness, unit pages for control, and detail/faceplate pages for individual devices. Each level answers a different question, and an operator should never need more than a couple of clicks to move between them.
Our graphical page standards
- Muted backgrounds with colour reserved for abnormal states, so an alarm is the brightest thing on screen.
- Consistent symbol libraries for valves, pumps, transmitters, and meters across every page.
- Live values placed where the equipment is, with engineering units always shown.
- Navigation that mirrors the plant layout, so the screen structure matches the operator's mental model.
Alarms, events, and trending
A graphical page is only half of the HMI. We configure alarm and event handling with sensible priorities and deadbands so the alarm list stays meaningful, and we set up trending and database (historian) connections so engineers can look back at any tag. Reporting functions — daily production, totaliser snapshots, custody transfer summaries — are configured to generate automatically.
Testing before it reaches site
Every display is exercised during in-house testing and Factory Acceptance Test: each animated element is checked against its tag, each alarm is forced, and each navigation path is walked. By the time the system is commissioned on site, the HMI has already been operated for hours on simulated I/O.