HMI leans into open software

Tobey Strauch, independent principal industrial controls engineer: Operator interface is such a general term because it encompasses hardware and software. The open human-machine-interface (HMI) software packages are taking over. Ignition by Inductive Automation has reset the standard for a prepackaged environment with great custom capabilities.

For hardware, the Touch Panel 600 by Wago has a high international protection rating, an edge computer on the back for programmable-logic-controller (PLC) operations and network ports to allow access to a switch to bring in remote I/O. This is an ideal package for small machine builders that are familiar with e!Cockpit and comfortable with the CoDeSys environment that Wago has built into its platform. The HMI is a computer with a screen and PLC capacity, as well as IIoT and cybersecurity functionality built in. The cost is half of a CompactLogix with no screen.

Open Automation Software (OAS) is also an open system like Ignition that has some depth in a niche part of the industry. The screen graphics are awesome.

What have been the biggest improvements to operator-interface technology in the past five years?

Tobey Strauch, independent principal industrial controls engineer: Operator interfaces have expanded into Web interfaces. This includes being able to control from a cellphone. Distributed control systems have been using terminal-emulation (server/client) HMIs for a long time. But now it’s going to regular HMIs and expanding to application-based access. Ignition Perspective is a downloadable app in the Google Store and has a built-in demonstration application that allows users to see what they can do with a cellphone.

AutomationDirect made its HMI Web-based almost 15 years ago, and, for the package price, it was the easiest to use. Of course, Rockwell Automation has had Web-server capacity built into its HMIs for a long time.

Physically, with the onset of Gorilla Glass and improvements in the cellphone world, HMI manufacturers are improving their screens. Touchscreens are more common, and it is easy to purchase an industrial touchscreen and adapt open software like Ignition or Beckhoff or Wago to run on the screen.

Also read: Hardware preference is immaterial in an open-source world

What’s the most innovative or efficient operator-interface technology application you’ve ever seen or been involved with?

Tobey Strauch, independent principal industrial controls engineer: HMI software is becoming more adaptable, in that there is compatibility with user-defined data types (UDTs) and the ability to repeat blocks. Being able to speed design process and communicate to the PLC easily and bring in tags for whatever needs to be displayed ensures fast design, and everyone wants the design to go as quickly as possible. Any software/hardware combination that eases development and still provides a good user interface is a win.

The end-product for a Siemens Simatic WinCC screen is pretty good, but WinCC can be labor-intense due to the database levels. Ignition still wins for me, based on ease of use.

However, Emerson DeltaV screens are comparable. I also like what Rockwell did to enhance its capability, as far as creating blocks that you can drill down into by double clicking. This is like the traditional distributed control system (DCS), in that the top layer shows a problem, with a change in color, and then you double-click and can get the equipment number and down to the tag to troubleshoot.

International Society of Automation (ISA) screen-development standards encourage this layered approach, so that the operator may have a snapshot, and then more detailed operations may be drilled down to. This alleviates the screens from being too busy but still allows a design element to work for operations and maintenance.

Also read: HMIs create a window of opportunity

How has operator-interface technology benefitted from remote monitoring and connectivity?

Tobey Strauch, independent principal industrial controls engineer: The operator interface is migrating to the office. Most plants want to be able to get a view of the operator interface on a Web page and cellphone application. The caveat is that they are not ready, based on network and infrastructure and cybersecurity.

Also read: Membrane puts the human in HMI

Can you explain how software development has changed operator interfaces in manufacturing?

Tobey Strauch, independent principal industrial controls engineer: Module-based software and object-oriented functions/libraries are making design easier. For instance, Siemens’ PCS7 has the Cemat libraries that allow a customer to buy. Cemat is set up specifically for the cement industry. This means libraries and HMI widgets are premade with the cement industry in mind. More packages along those lines would allow HMI design to go more quickly. Everyone uses linear actuators and servos. Thus, make a premade servo interface with enable, disable, jog forward, jog back.

Also read: Operator interface benefits from increased transparency to runtime data and system support

How do operator-interface technologies figure into digital-twin platform models being used by manufacturers?

Tobey Strauch, independent principal industrial controls engineer: The distributed-control-system guys have been doing this for a while. Emerson and Siemens have been pushed to simulate platforms due to the continuous-process environment. This allows a design period, debugging and operator-training strategy to happen before cut over. Machine builders need to consider this before creating assembly lines.

Platforms like Ignition and OAS that are open-based and may run server/client, allow this to happen. Discrete manufacturing will do it more often as discrete lines continue to put more complicated functionalities in and have more robotic/autonomous interfaces.

Also read: Is open-source HMI software the way?

When will operator interfaces become IT-friendly enough that engineers are no longer required for installation and operation?

Tobey Strauch, independent principal industrial controls engineer: Virtual machines and server-based applications allow easy remote access. However, the safety issues with controlling a machine remotely are always a concern. Also, there is a depth-of-knowledge gap. Can people that did not build the system or are unfamiliar with operations be able to modify remotely without boots on the ground? Design would have to be better.

What future innovations will impact the use of operator-interface technology in manufacturing operations?

Tobey Strauch, independent principal industrial controls engineer: Eventually, handhelds will take over. This means a wireless infrastructure with a central control, but this paradigm has happened before. It is interesting that with the convergence of information technology (IT) and operational technology (OT), there seems to be less of a demarcation line with distributed control systems and discrete manufacturing systems. Customers want machines connected to material handling, enterprise resource planning (ERP), scheduling, quality and any other acronym system. This means machines no longer stand alone. It also means that, if we provide better automation, one operator may work a whole line. This makes a pocket interface more viable.