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The trends in PC-based control are to divide and conquer, take a page from consumers, and get networked. For machine builders, these advances promise easier real-time control.
The strategy of divide and conquer benefits from hardware changes. Chip vendors produce system-on-chip (SoC) solutions with a growing number of diverse and specialized cores.
"Today's multicore SoCs are comprised of multiple CPUs of both similar and different 32-bit cores with specific execution engines for graphics, networking, process control, plus analog and digital I/O," says Dave Mender, vice president of business development for real-time operating system (RTOS) supplier Green Hills Software. The company's software helps manage these various cores. He says this is part of a trend toward consolidating high-level PC-based functions with real-time process control into one platform.
The advent of industrial PCs with multicore processors allows control and other functions to be handled in one system, says John Wilhite, product manager for PC-based automation at Siemens Industry. "In the past, you might have needed an HMI with its own processor and a PLC with its own processor. There might have been a PC to capture that data, and send it to an enterprise system. Now all of that will be controlled by an industrial PC [IPC]," Wilhite says. He adds that the company's real-time software controller and its failsafe version support several RTOSs.
More processing power and resulting platform consolidation feeds another trend: consumerization. For example, consider the July announcement by Beckhoff Automation of its four-core, Intel-i7-powered panel PC. Reid Beilke, IPC and embedded PC product specialist at Beckhoff, points to its consumer-device-like, multi-touch technology and benefits.
"Early adopters of the technology are implementing more intuitive and interactive HMIs that are much more in line with modern electronics users," he says.
Of course, not all processors are created equal. Some consumer experiences, such as gesture recognition or overly complex user interfaces, are computationally too taxing to recreate on a factory floor, particularly on embedded systems that are older and less powerful.
Products from RTOS vendor QNX Software Systems mitigate these resource constraints with adaptive time partitioning. This means the control loop or some other function might be guaranteed for at least 20% of the system, but that allocation is not fixed.
"If you've got work to do and no one else is ready to run, we'll actually give you the rest of the CPU," says Grant Courville, QNX's product management director.
He adds that users of PC-based controls do want a consumer-like experience. If this is to be done in a cross-platform way, then one solution to use standards such as HTML5, Qt and OpenGL ES, Courville says.
A final trend in PC-based control development is increasing connectivity, which is expected to explode with the arrival of the Internet of Things. The industry has incorporated sensors and automation in workflows for decades, yet only about one in 10 legacy systems currently is connected, notes Michel Chabroux, senior product manager at Wind River. Among the company's products is the VxWorks RTOS.
As things change and connectivity expands across the factory floor to devices that previously were isolated, embedded systems increasingly will be concerned with cyber security. That will place additional demands on real-time operating and PC-based control systems, which in turn will require new must-have capabilities.
"An RTOS must give customers the flexibility to design their embedded system to the necessary level of security by leveraging a comprehensive set of built-in features covering design, boot and execute, operation and power down," Chabroux says.
The ability to create independently operating partitions could do more than make real-time control easier. It could also make achieving needed cybersecurity more feasible. For instance, an HMI or a partition running Windows might be allowed to talk only via virtual Ethernet to a firewall.
Such virtualization and abstraction of hardware can protect an embedded system against cyber assault. However, it must be done in a way that preserves determinism and PC-based control, says Kim Hartman, vice president of sales and marketing at RTOS supplier TenAsys.
Moving everything to one platform might not be that painful thanks to multicore technology and power, he adds. "You can afford to bring your existing workloads and existing operating systems into this environment with little—or possibly no—changes whatsoever." Â
