ABB High performance HMI

Leading paths to greater awareness, faster response and better decisions

Handling the unplanned outages has become the number-one priority for many companies today. On an average, operators deal with thousands of alarms per day. Hence, they should face no more than two alarms per 10-minute period but alarm overload distracts the operators and often causes unplanned downtime.

For maximum plant performance, high performance HMI and advanced alarm management helps to improve the operator's tools and work environment. An ABB case study reveals savings of more than $800.000 from upgrading to a high performance HMI.

Importance of HMI

In control rooms of old, the number of alarms was limited by the amount of space on the control room panel board and the cost of wiring equipment from the production area to the board.

Annunciators, indicators and switches (to acknowledge and clear a resolved alarm) had to be essential to justify a place on the panel. If a new alarm was needed, an existing alarm would usually have to  make way.

This began to change with digital signals and the distributed control system (DCS) in the 1980s. Panel boards were replaced by monitors and servers, and signals were transmitted from plant equipment to computer processors, where the signals were turned into actionable information. But the alarms were overloading the control room and terms such as flooding, nuisance, chattering, fleeting and stale were coined to describe them and their effect on the operators.

The modern HMIs are equipped with high performance grayscale graphics, using color carefully and provide effective alarm handling and analysis.

The new generation of HMIs has a huge impact on operator performance:

• they improve the operator’s ability to detect abnormal situations before an alarm occurs by a factor of five;

• the operator success rate in handling abnormal situations is almost 100 percent; and,

• the time it takes to correctly handle the situation is almost half that of operators working with traditional HMIs.

Besides grayscale graphics and the consistent and careful use of color, shapes and motion, high performance graphics typically include the following features to maximize the attention and effectiveness of the operator:

• Alarm priority colors are used for alarms only

• Consistency in graphic layout to ensure operator situational awareness

• Tab-based navigation for one-click access to primary displays

• Embedded trends, which display historical data in a graphic to efficiently draw the attention of the operator to abnormalities and deviations

• The normal operating range and high / low alarm limits are shown for each item of equipment using an intuitive bar graph (see Figure 5)

• Bubble-up alarming allows the alarm with the highest priority to ‘bubble up’ above lower priority alarms associated with the same device

• Integrated help displays in the form of pop-ups

• Extendable faceplates put all the information the operator needs in one place

• Level 1 surveillance of the entire plant or unit in one graphic to facilitate rapid visualization of the entire process, as well as KPIs

• Level 2 visualization of specific parts of the process, providing alarms, information and controls for each area and easy navigation to level 3 graphics (P&ID style displays)

• Alarm macros for condition-based alarming, if each alarm condition needs to be managed individually