Essential features for rapid HMI/SCADA development

Posted: January 19, 2024

In the 15 years I’ve spent in the operations control space, I’ve seen quite a few evolutions of HMI software. Through the years, I’ve seen new upgrades and innovations that have withstood the test of time. I’ve also seen new features, heralded as game-changers when they were released, that have disappeared as quickly as they arose.

Of the many innovations I’ve seen come and go (or stay), a few stick out in my mind as must-haves for any modern HMI SCADA development. Some of the most important of these include a powerful graphics library, a template-based design, and simulation tools. These functionalities can help you create projects with fewer errors, reduce maintenance, and future-proof your applications.

This blog post will overview key features in AVEVA™ InTouch HMI that enable system builders to rapidly develop HMI applications.

Powerful graphics  

Below are some aspects that make AVEVA™ Industrial Graphics the most powerful graphics library on the market.

Polar star symbol

Process control begins with understanding your process variables. These variables can be interdependent in a single process. Controlling each variable manually would be difficult, time-consuming, potentially hazardous, and likely to introduce errors. Fortunately, AVEVA InTouch HMI simplifies complex tasks. 

One of the advanced symbols is the polar star, which shows a set of related process values on spokes that form a visual polygon. As values change along the length of the spokes, operators can easily recognize the changing shape of the polar star’s polygon and react quickly to abnormal process conditions. Each spoke contains an array of custom properties with which to set value set-points and alarm limits and coordinate set-point locations for the normalized process value. When a process value changes from its set-point location on a spoke, the animation changes the shape of the polar star polygon. 

Scalable vector graphic (SVG) support

With support for SVG, AVEVA InTouch HMI drastically reduces the effort needed for HMI development. You can import externally created SVG graphics, whether they’re saved as image files or converted to the AVEVA Industrial Graphics format. Rich animations and pixelation-free SVG graphics that are truly crisp regardless of image size improve the end-user experience.

Resolution independence based on aspect ratio

In a world in which ever more devices with diverse form-factors abound, users often need to design applications of uncommon sizes or simply to design an application for displays the designer has no access to. AVEVA InTouch HMI now allows users to design applications in a target resolution different from the development machine.

You can resize or stretch resolution-independent graphics without losing the original visual quality, which improves window display performance and lets you reuse graphics designed in one resolution in a different resolution without distortion.

Templated HMI design

Release developers from mundane, repetitive program tasks and maximize re-use through the development of common components for larger, more complex operations control systems. 

User-defined types (UDT) structures and object-oriented graphics

Undeniably, tags are useful in their own right. They’re simple, and it’s easy for users to migrate them from one project to the next. That said, tags don’t deliver the most intuitive experience for every application. You can’t use tags to link elements together into complex structures with built-in relationships and interdependencies. Thankfully, there’s another way. 

User defined types (UDT) templates, along with object-oriented graphics, let you create your own structures to match field equipment or existing structures in your PLCs. Developers can create user-defined data types (UDTs) in the controller to model plant floor process equipment. Users can then reference it with multiple instances as necessary. For example, if you have many tanks, you can develop one UDT to represent them and then use multiple instances of the UDT mapped to each tank.

UDTs are a time-saving tool that enables an object-oriented approach. UDTs are best with repetitive structures, and you should use them when you plan on having multiple instances. UDTs are a way to make a parameterized data template and indirect object referencing. Once you’ve defined the composite data structure, you can create an instance as if it were a single tag.

In AVEVA InTouch HMI, UDT instance members behave like any tag and support industrial graphics symbols, animations, scripts, historian and alarms. Every instance of a UDT will conform to the UDT’s structure, and if you make a change to the definition, all instances will automatically inherit it.

Application and window templates

Another great productivity tool, application templates allow users to design a new HMI application from a base template instead of starting from scratch, saving hours and hours of engineering. Application templates can be as simple as a navigation framework or as rich as the user desires.

AVEVA InTouch HMI windows can also be defined as templates. This lets you create new windows from them that inherit all of the properties, content, and scripts from your original window. This feature helps you save time on engineering.

Users select application templates via a template browser, which provides a thumbnail preview of the templates. They can organize application templates in a folder structure of their choice—by resolution, industry, customer, or engineering team, among others. A number of application templates are available out-of-the-box, but you can also create your own.

System integrators can reuse their engineering in multiple projects, OEMs can deliver base applications to their end users, and new users can get started in a shorter time. 

AVEVA™ Communication Drivers simulator

A simulator tool is invaluable for testing your configurations and graphics, especially in situations where physical PLCs are unavailable. Simulators enable rapid engineering development.

The AVEVA Communication Drivers simulator provides simulated data for OPC and SuiteLink clients to exercise data connectivity. This powerful simulator driver comes out of the box as part of AVEVA's standard communication drivers pack, which simulates data for client applications like AVEVA InTouch HMI and AVEVA™ System Platform. 

This new capability gives you the ability to build and test any monitor configuration or HMI resolution content that is optimized to perform on every display screen—the first time, every time.

Owing to the savings, ease of use, and efficiency gains these capabilities bring, I can say that of the many operations control software features I’ve seen, these features mentioned above are worth considering—and keeping.