Use Software to Customize the HMI

May 27, 2009
Tailor-Fitted HMI: Operator Interface Hardware Can Accommodate the Needs of the User and Look Good Doing It

Software choices about branding and image come into play when machine builders decide to provide their own unique operator interaction bycustomizing the human-machine interface (HMI), rather than settle on the default interface of the vendor.

If a machine builder sells into an industry in which control traditionally was accomplished with physical control panel operations and indicators — where operators aren’t accustomed to seeing full-featured HMIs — making the screen appear like the control panel can be a big factor in encouraging adoption. It can lower training costs for the machine builder’s customers. This also can be important in a global market where language might be an issue.


“The old saying that a picture is worth a 1,000 words applies,” says John Weber, president of Software Toolbox (www.softwaretoolbox.com). “If the operator can look at the screen and say, ‘I know what that means because it looks just like the physical control panel,’ then it’s an obvious win.” How much an OEM can customize the HMI depends on the software in use and whether it’s off-the-shelf or homegrown, adds Weber. “If they’re using an off-the-shelf HMI package, they need to look at whether the HMI software allows for standards-based, third-party plug-ins. Most HMI software packages have their own vendor-specific interfaces by which third-party products can add functionality. But having a standards-based interface will give the OEM machine builder the most choice.” The two most common standards to look for, says Weber, are support for ActiveX controls or .NET user controls.

Almost all operator interfaces are based on existing HMI toolsets, says Blair Sooley, pre-sales engineer for Trihedral Engineering (www.trihedral.com). “Few companies will develop their own functionality because it is too difficult to get all the pieces to work together,” he notes. Interfaces are often so highly customized that a lot of functionality isn’t directly supported out of the box, or if it is supported, it’s difficult to get the mechanism to work correctly, says Sooley.

Gary Labadie, marketing manager for Pro-face America (www.profaceamerica.com), says a machine builder needs to decide how far it should take the brand name and image and apply it to some or all parts of its machine. If machine builders seek a unique look, they should brand the operator interface hardware, datasheets, manual and brochures, as well as the operator interface, he says. “Done right, there are times I look at what a machine builder has customized, and I can’t tell from the front that it really is our equipment,” says Labadie.

Further customizing the operator interface can be simple, “unless it’s customization that would interfere with machine operations such as operator safety, liability, warranty and serviceability,” says Labadie

Roy Kok, vice president of sales and marketing for Kepware Technologies (www.kepware.com), says HMIs are extremely flexible today, to the point that they can be completely customized for OEM use. “When running, you wouldn’t know whose technology is behind the interface,” he says. “If custom graphics or screen controls are needed, all HMIs have the ability to import third-party graphics, ActiveX or .NET controls.”

Customization is extremely important to both machine builders and machine users, says Tim Donaldson, director of marketing for Iconics (www.iconics.com). “They need to be able to have a graphic screen work with their hardware,” he says. “So they need to build the HMI screen to have the right data points tied to their hardware and have the right graphics display on there.”

Donna Smalls, HMI/SCADA product manager for Schnedier Electric (www.schneider-electric.com), says users save time by creating a master panel of common objects and shared interface controls that can be applied to multiple panels in an application. “You can use either one master panel or layer multiple master panels,” she says. “Master panel layers allow you to choose the common objects that will show up on a panel and to determine the order in which the panel layers will be displayed at runtime. With master panel layers, you have the flexibility to use a master panel that contains all common objects or one that only contains select objects.”

The HMI industry is trending to more simplistic interfaces that follow either company or industry interface design standards, says Linda Onnen, global director for consumer products and original equipment manufacturers at GE Fanuc Intelligent Platforms (www.gefanuc.com). “Typically the end user isn't aware of the HMI software type unless they are in development mode,” she says.

Nathan Massey, regional sales manager for B&R Industrial Automation (www.br-automation.com), says it’s critical for many machine builders to create custom HMI by using both visualization software packages and customized hardware options. These create a solution that is specific to the machine builder and allows the machine builder to more closely meet the needs of end users, he says.

Phil Burgert is a freelance writer, specializing in technical trade media.