An iPhone as Your Next HMI?

Consumer-grade smartphones and tablet computers are fast becoming commonplace extensions of industrial networks, permitting process monitoring and, even (gasp!) process control.

By Peter Welander September 1, 2011

It was a typical buffet breakfast at a process industry user group meeting. Your correspondent was enjoying an unhealthy dose of high-cholesterol selections and making small talk with other attendees. One took out his Apple iPad and began checking email. After a few moments, the discussion turned to ways he used that device, and he said, very of matter-of-factly, that he could use it to access his plant networks using a wireless Internet connection and see how the process was running. If necessary, he could log in and even control the process via that device. He and one other colleague had the credentials to do that. This was not some young tech native, but a gentleman probably in his sixth decade. The plant in question was a full-scale paper mill.

It’s possible that he had become blasé about the level of technology that it represented, but I suspect he realized that the others of us at the table found the whole idea fascinating and maybe a little scary. The notion that such an interface is practical over the Internet, wirelessly, and using an off-the-shelf Apple device, stands much industrial networking convention on its head. What’s next? Controlling a chemical plant with a Mac? That may be a bit too much, but why shouldn’t industrial applications use this level of convenience, provided there is an appropriate level of security? Smartphones and tablet computers, regardless of the manufacturer, are hugely powerful and represent a useful extension of industrial networks, especially Ethernet- and Web-based communication. Apple claims there are more than 425,000 apps available for iPhones, so it’s no surprise that some extend into industrial contexts. The number of offerings for Google’s Android platform is not far behind.

Many industrial system suppliers, particularly those that are a level removed from large plant-wide control platform suppliers, are working with these types of apps, providing extensions of plant networks in process and discrete manufacturing. The basic concept of this is not all that new. Earlier versions typically used an interface to send automated voice or text messages to operators’ cell phones if specific events happened. These were particularly popular in applications such as enabling an unmanned pumping station for a water utility to send an automated alarm message. Such uses go back into the 1990s and are still available today.

However, today’s applications are vastly more sophisticated, taking advantage of the growth of wireless networks, the growing capabilities of portable devices, and rapidly expanding Ethernet networking. Once a system is connected to the Internet, all such barriers disappear, for better or worse. Moreover, the mind-boggling proliferation of applications for smartphones and tablets seem to enable just about anything from anywhere. As tech natives move into manufacturing, there is an expectation that such capabilities are available as a matter of course.

Adding mobility

Most major control system suppliers have added some mobile worker HMI (human-machine interface) capability via wireless devices, often using ruggedized armor-plated laptops, such as Panasonic Toughbooks, although such connectivity usually doesn’t go much beyond the fence. However, compared to an iPad or smartphone, these are bulky, heavy, and expensive. Consumer-grade devices are usually considered too fragile and there is no certification for hazardous locations. Still, proponents contend that every device does not need the ability to work from any conceivable location in an oil refinery. In most applications, consumer-grade devices are more than adequate, and their ubiquity enables virtually anyone to have one.

Driving the process

“Mobile access is driven by the need for continuous ubiquitous viewing, from management watching production to an operator remotely adjusting a process,” says Mark Lochhaas, automation I/O product manager for Advantech Industrial Automation. “Using a smartphone to access SCADA or HMI data is simply a type of thin client function on a small wireless platform. Conceptually, any device that can browse the Internet could be used to dynamically access automation data, either real time, or historically, perhaps from the cloud. The server must be able to host a mobile app, and the mobile device must have an app that is compatible with the host.”

The companies that are pressing this development are not necessarily the large control system architects, but smaller companies that support networking and are more willing to experiment with new things. Most of the driving force has come from the IT side, reflecting growth of mobile applications on that side. “Within the convergence of IT and the factory floor everything is being connected, from individual devices to factory floors being connected to supply chain management systems to integration with the rest of the business,” says Brian Vezza, director of machine-to-machine (M2M) solutions at Wind River. “The combination of M2M, cloud, and smart consumer devices is driving powerful new business opportunities for industrial, energy, medical, and other markets. Within the manufacturing plant environment, M2M devices enable enhanced situational awareness where plant managers, business leaders, and others can see a much deeper understanding of their operating environment, resources, objects, and things. By combining information generated from M2M devices with other systems (e.g., the context) and using analytics or other forms of control and/or business logic, business becomes more intelligent and valuable.”

Designing the app

While there is some commonality between providers in equipment selection, there is a much greater variety of functionality. For the context of this discussion, we will stay in the area of apps that are extensions of product platforms (as opposed to something like a savings calculator or configuration selector) and available for purchase off the shelf, typically from iTunes, rather than those that are purpose built for a specific application. That’s not to say they won’t require some customization, but this is done by the individual user. Such apps are also very inexpensive, often less than $10 or even free.

Some companies design their apps to interface with specific types of hardware, while others create systems that are more platform agnostic. Here are two contrasting examples as illustrations: Opto 22 and ProSoft Technologies. While their applications both involve HMI functions including control, the underlying concepts and approaches are different.

Opto 22

Opto 22 has released its iPAC iOS app that is designed to communicate with its SNAP PAC system using Apple iOS devices (iPhone, iPod Touch, and iPad). The app goes into the control network via the wireless network and seeks out those devices. Once it finds them, establishing communication is very simple. The company says that a user with proper security credentials can inspect SNAP I/O points and PAC Control strategy variables, and execute control functions such as turning digital output points on or off, writing values to analog outputs, and changing control variables and table entries. Specific I/O points and tag names can be retrieved, viewed, and saved to a watch list for future reference.

“For us there is no hardware interface required. With the iPAC application installed on a mobile device that runs the iOS operating system, which basically means Apple, the first thing that is required is a wireless network,” says Benson Hougland, vice president, Opto 22. “The main reason for that is these mobile devices don’t have an Ethernet jack, so the only way to access information of any kind is via wireless. All of these devices include Wi-Fi, but they don’t all include a 3G connection. The second thing you need is access to the control network wirelessly as well, but the question is how many people have their control system network accessible from their wireless network. There’s going to be a large share that do not. Naturally that has to be a secure network. Most people realize today that they don’t deploy wireless networks without strong security that is part of any wireless network hardware that you can buy today.

“This is not meant to be an HMI tool that connects to any hardware devices. This product was designed specifically to communicate with Opto 22 controllers and brains. It’s predominantly used for commissioning, troubleshooting, maintenance, and things like that. It’s only useful for people using Opto 22 hardware, but future products may have additional capabilities.”

Process Engineering Resources in Salt Lake City, UT, is an Opto 22 customer and is experimenting with using iPAC as an extension of its x-ray-based metallic ore analyzers. “Our biggest use for the iPhone app is that it’s going to control our sampling system,” says Dave Taylor, systems engineer, but he makes the point that the iPhone functionality will not be available for the customer. “It will be the most valuable for our people that are doing the installation. We can stand at the multiplexer tank, which might be 20 or 30 feet from the analyzer, and select a stream using the iPhone. You can activate the I/O directly to verify that it’s working, that you have enough pressure, and that sort of thing.”

Taylor adds that being able to verify that all the components are operating and that all flows are what they need to be without constantly running back and forth is a significant step. “I did it once using a PC and a wireless connection, but it’s much more convenient on a hand-held,” he says.

ProSoft Technology

ProSoft Technology says its recent release of the ProSoft i-View mobile app provides an easy way for users to monitor their control applications in real time from an iPad, iPhone, or iPod touch. Functionally, the app enables wireless connectivity to any PLC/PAC that operates on an EtherNet/IP or Modbus TCP network, via Wi-Fi or remotely via cellular. For security, the user must have access to both the wireless network and the CPU of the processor to set it up. During configuration, the app requires the user to assign a matching security code both as a password for network access and as a security tag in the CPU of the PAC. From this point forward when a user launches ProSoft i-View, the security code must match that on the CPU in order to create a connection, preventing unauthorized users from simply downloading the app and hacking into the system. Where the wireless network is concerned, the same considerations must be given that would apply for any industrial application when selecting the technology and provider. ProSoft Technology’s Industrial Hotspot radios, for example, feature WPA2-PSK and 802.11i RADIUS security, which prevent unauthorized access and modification to the network, and are fully supported by a leading team of application engineers and an array of complementary tools, such as the ProSoft Wireless Designer.

During setup, the user must configure the tags within ProSoft i-View, then establish their variance allowances. Once operational, the app displays live PLC values in stylized lists and graphs. Alarms are also available, including local notifications, to alert maintenance teams when a deviation from setpoints occurs, for example. Via a cellular connection, these engineers are able to monitor variables in real time and make adjustments from virtually anywhere with cell phone coverage.

“Application use cases are wide,” says Adrienne Lutovsky, marketing communication specialist for ProSoft. “System Integrators have used the app with our cellular radios to remotely troubleshoot customer installations. A small packaging operation for dairy products desired the app to keep an eye on the control system from home. The latest upgrade includes a barcode scanner, which expands use case scenarios into areas like quality control.”

ProSoft says one global automotive manufacturer is evaluating this approach in a quality assurance segment of its finish line, where vehicles are inspected for leaks. Presently, inspectors drive cars into a pressure-wash booth, where they perform visual assessments of the inside of each vehicle before driving the car to an HMI system in order to manually record their findings. Under the new approach, each vehicle would be marked with a barcode at all test points, and the inspectors would be mobilized with the app via tablets, connected wirelessly to the PLC using ProSoft 802.11 industrial hotspots. Any points in the vehicle that do not pass pressure-wash inspection would be scanned and automatically recorded to the PLC, effectively minimizing test time.

Will performance stand up?

Time will tell if network performance will support customers’ expectations. Any smartphone user has had to deal with the frustration of pages that take too long to load or networks that can’t deliver. While Wi-Fi and cellular networks are improving, connectivity at some point is going to be a disappointment. Such experiences will determine how common these applications become.

Even so, the possibilities are appealing. “The ease of cloud connectivity combined with smart tablets and phones means that this information can be available in an easy-to-use and secure manner whenever and wherever it is needed,” says Vezza. “Android and iPad style smart tablets combined with smart systems bring unmatched awareness, accuracy, and control to leaders to monitor and manage their resources in near real time to meet their business goals. Those goals may include improved service delivery, lower cost, customer responsiveness, new or enhanced products, and service offerings, etc. By providing standardized M2M device development kits and optimized development frameworks for both hardware and software, device manufacturers can focus on their own value-add and differentiating functionality instead of the underlying hardware, OS, and core M2M software.”

Peter Welander is content manager for Control Engineering.


For more information, visit:

This is the August 2011 Control Engineering print and digital edition cover story. Print and digital edition subscriptions are available here:

Registration Form