Detailed Design Principles of High-Performance HMI Display

Welcome back to our series of What is High-Performance HMI? In the previous installments, we covered the current state of HMI’s and justification of change to High-Performance HMI as well as the fundamentals of High-Performance HMI and High-Performance HMI standards. In this installment of the series, we are going to talk about the detailed design of a High-Performance HMI Display.

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High-Performance HMI hierarchy

A well-designed High-Performance HMI will generally consist of four display hierarchies. These are known as:

1) Process area Overview;

2) Process Unit Control;

3) Process Unit Detail;

4) Process Unit Support.

Each display will generate more detail and zoom in on the process.

The philosophy behind the display levels is to give the operator the information that they are looking for without having data all over one or two different screens.

As we talk about the display levels, you will become familiar with the design and purpose of the Level displays.

Level 1:  Process area overview

In a High-Performance HMI, your project will start with the Level 1 Display, and its primary purpose is to give the operators the broadest view or the big picture view of the plant or facility.

A well-designed Level 1 display will give clear information of the current state of the process.

It will also gives you info about the Key Performance Indicators such as production levels, process efficiency, and safety items.

Most times, Level 1 displays will not have many graphics but will be more information-based and give the operator easy navigation to Level 2 displays.

It will also give the indication of major upstream and downstream processes and finally will provide visual indications of abnormal situations and alarms.

Level 2: Process unit displays

From Level 1 displays, the operator will have the ability to select a Level 2 display.

As the display hierarchy flows from high level to detailed views, the next display is the Level 2 displays.

Level 2 displays should include the information and controls that are required to perform most tasks on the particular process that was called from Level 1. Accessing Level 2 from Level 1 is a one-click operation.

The purpose of Level 2 is to provide a clear picture of the systems in the process selected from Level 1.

Once in Level 2, the operator now has the ability to operate process equipment such as pumps, valves, and compressors.

Layout and P&ID

While it is important to follow the physical layout of the facility and the Piping & Instrumentation Diagram, or P&ID, Level 2 screens should not look like a copy of the P&ID.

Remember from previous lesson, Development of High-Performance HMI Philosophy, that equipment relative size, line weights, and proper process flow directions are key to a great-looking Level 2 High-Performance HMI.

Level 3: Process unit detail

Moving on to a Level 3 display will provide detailed views and information from the Level 2 compressor display such as runtime, faults, alarms, commanded speed, and speed feedback.

It could also include a custom trend showing process values such as pressure or flow.

A Level 3 display will also include detailed diagnostic displays and interlocks.

Detailed Level 3 displays are intended for advanced control and troubleshooting, items that are not available on Level 1 or Level 2.

Remember, many Level 3 displays may be accessible from a Level 2 display.

Level 3 displays can be attached to pumps, compressors, valves, tanks, and process instrumentation.

They are meant to provide the operator with a detailed and complete view of a process or a device, along with advanced control capabilities.

Level 4: Process unit support

Now let’s discuss Level 4 Displays. Level 4 Displays in a High-Performance HMI are obviously going to provide the greatest detail of sensors, subsystems, and individual components.

In some cases, a Level 4 Display will provide information on PLC processor performance and the health of Input and Output channels.

This display is meant for extensive and advanced troubleshooting, interlock programming, and process setpoint adjustments.

You will also be able to view operating procedures, alarm response instructions, and abnormal situation response guidance.

Pop-up information-driven display

When responding to an alarm using a Level 4 display, the information about each alarm should be visible to the operator. When possible, use a pop-up by utilizing a right mouse click on the alarm to provide a highly detailed and information-driven display that will give the operator clear instructions on the alarm and how to effectively troubleshoot it.

While Level 4 displays are highly advanced, they aren’t always going to be graphic-driven. Remember, in High-Performance HMI information is above all else, and fancy graphics can be retired to the HMIs of days of the past!

Some of the graphics and the HMI screens used in this article are from the High-Performance HMI handbook which is a great reference if you want to dig deeper into this topic.

Summary

Ok… let’s review what we have learned in this article:

1) Level 1 display is the situational awareness display, and only one Level 1 display is needed in a High-Performance HMI.

2) Level 2 displays are accessed from Level 1 and provide a picture of the process, and the equipment within it.

3) Level 3 displays are attached to the process equipment depicted in Level 2 and will give control detail and in some cases a moving trend screen to view process values in real-time.

4) Level 4 displays are the highly advanced alarm and information displays.

5) High-Performance HMI’s are fundamentally driven by information and not data.

Want to Learn More?

We hope you enjoyed this series on High-Performance HMI. We recommend checking the following related articles, if you haven’t already, to have a better understanding of High-Performance HMI Display:

What is High-Performance HMI? (Part 1 of 4)

High-Performance HMI Design Basics (Part 2 of 4)

Development of High-Performance HMI Philosophy (Part 3 of 4)

▶ Detailed Design Principles of High-Performance HMI Display (Part 4 of 4)

If you have any questions about High-Performance HMI Display or about HMIs in general, add them in the comments below and we will get back to you in less than 24 hours.

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