A Slice of Pi and the IIoT’s Appetite for Diversity
Intel® Core™ i7 processing and open standards are meeting the IIoT’s varied I/O, graphics, and expansion demands when just dessert isn’t enough.
Solutions aimed at Internet of Things (IoT) applications keep on coming, with Raspberry Pi and other high-volume, basic feature, low-cost computers forming the basis for much of the market. But many applications—particularly Industrial IoT or IIoT—will require more diversity in I/O, graphics, and expansion. Versatility in I/O from open standard specifications like Mini-ITX, COM Express, and SBCs like 2.5-inch Pico-ITX can be a significant benefit for the industry.
A Slice of Pi
Yes, the Raspberry Pis of the computing world are simple and offer “good enough” performance at a very low cost. With their low-power processors (typically about 1.2 GHz), GPIO, USB, HDMI, GbE port, Bluetooth connection, etc., such computers cover the basics. So, you can have good graphics, solid data processing, communications interface, and the basics in I/O. The memory is quite low with basic RAM, but for the basic applications it is enough. For simple devices, these features cover the gamut of needs quite well in a small and light form factor.
However, it doesn’t take long for the features of the simple computing boxes to fall short in a breadth of applications. For example, when sensing comes into play such as in machine vision, robotics, and many human-machine-interface (HMI) applications, typically more features are required. IIoT applications gather data from devices, provide feedback and communicate among the various factory floor systems. Data analysis allows managers to make process and manufacturing improvements to become more efficient. To achieve this, multicore processing with enough PCIe lanes is required. Also, the benefits of scalability, expansion, and a versatile feature-set for multiple applications are critically important.
I/O, Memory, and Expansion
Taking an open standard architecture, with its rich diversity of implementations, vast ecosystem of vendors, etc., is a key start. Even the very small 2.5-inch Pico-ITX SBC has all the features of the small computing kits we have mentioned, but has the added flexibility of I/O interfaces, expansion, and storage interfaces. There is also significantly more memory with the advantage of DDR3 performance.
When sensing is a key part of the system, typically more efficient and larger capacity storage is required than the basic boxes can provide. Interfaces to SATA/SAS storage give room to expand as system requirements grow. And extra MiniPCIe, PCIe, or other expansion slots make future growth possible while offering the flexibility that allows the user’s systems (automation equipment, etc.) to be used in more applications. If, for example, a factory using automation equipment expands operations, that factory would be able to expand the number of production lines without starting from scratch.
Offering versatility in the Graphics and I/O ports is also beneficial. Some applications utilize legacy equipment, which may vary greatly on a customer-by-customer basis. So, having VGA and DVI options in addition to HDMI is a nice benefit.
Open standard, rich-computing-option Mini-ITX systems address SFF computing with benefits not available in Pi and other very low-cost systems, including:
• Performance—with more powerful processor options such as Intel Core i series, multicore, and more PCIe lanes for lots of functionality
• Greater memory and storage capacity—helping to facilitate the increased functionality
• Expandability with PCIe—this is important for many automation systems for the use of controller boards, frame grabbers, etc.
For example, the unit in Figure 1 has a Mini-ITX board inside providing 2.66 GHz (3.33 GHz Turbo mode) of power at 35 watts in an air-cooled system. The dual core processor has up to 16 PCIe lanes, allowing the unit plenty of lanes for a 2.5-inch storage bay, an optical drive, GbE, COM and LAN ports, plenty of other I/O and graphics ports, and 8GB of DDR3 memory. Mini-ITX is standard and ready to go without any hardware customization. Although this example embedded system is small, there are smaller versions with lower-power processors for fanless or completely sealed versions—a “plus” in many factory floor settings.
Today there are powerful processors in Intel Atom™ designs that have low power usage and dissipation requirements. This gives us more bang for the buck and facilitates the use of fanless systems. Many of the IIoT applications will require small and light enclosures to house the electronics. By using open standard motherboards and SBCs, there can be several optimally sized enclosures with various performance levels and interfaces. In some versions, just a panel can be modified to accept different I/O options. With multiple processor options, on the same form factor board, the exact requirements of processing power, PCIe lanes, and other features such as memory and integrated graphics can be achieved.
A significant amount of the designs of IIoT will require industrial-grade components and ruggedization. This is especially true for robotics or in applications where the computing system will be transported or moved often. With a conduction-cooled clamshell, a SFF computer can provide a higher degree of ruggedization and increase reliability while foregoing one of the most common points of failure—the fan. Figure 2 shows a conduction-cooled sealed system with a standard 4-inch SBC motherboard inside. Since the enclosure does not have a fan, the processor selected is a quad core 1.91 GHz Atom processor that uses only 10W of power. This is easily cooled with cold plates in the sealed enclosure. Although even more compact than the fan-cooled system mentioned earlier, this unit still has the space and connectivity for plenty of I/O and dual GbE ports. The unit also has a 2.5-inch storage bay, an mSATA storage module via one of the 4 MiniPCIe expansion slots, a SIM card slot, and an optional microSD socket. Another benefit of the conduction-cooled clamshell approach is that it adds a level of ruggedization. This example unit meets MIL specifications for operating vibration and can withstand 3G of operating shock at half sine wave 11ms in 3 axes.
COM Express is an attractive alternative as an easily upgradeable and customizable approach. A carrier motherboard is designed into the application, with pluggable COM Express mezzanines that plug into them. As requirements/performance levels advance over time, newer generation standardized COM Express modules can plug into the same motherboard. The various small form factor size options and high performance of the architecture is a benefit. There are, however, typically higher up-front development costs.
Open Source vs. Open Standard
The open source groups tend to focus on specific product designs, where even the Gerber files, schematics, and mechanical drawings are included. This lends itself to monochrome, commodity products with little differentiation. Open specification/open standard groups on the other hand define focus on common interfaces for interoperable products rather than finished products. Multiple vendors contribute to the base definitions and interfaces, but the implementation can vary greatly. Industrial Automation and IoT require a lot of I/O and processor differentiation, so the open standards/specification route is often greatly preferred. There are also benefits of scalability, multi-vendor interoperability, and a broad ecosystem of proven products by utilizing open standard architectures.
More for Less
In IIoT applications the multicore processing, expansion, and storage are critical for the sensing and data analysis requirements of those systems. Using open-standard motherboards and SBCs as a basis for small embedded computers provides scalable, multi-vendor options with a wealth of I/O possibilities, which is a key requirement for automation and many other applications.
Justin Moll is a dedicated consultant for DFI Tech.