Although the IIoT is poised to reshape factory automation, transportation, energy, and other industrial markets through the application of intelligence and connectivity, the embedded systems that power these segments are still governed by longevity, reliability, and low power consumption. Meanwhile, however, the use of higher precision sensors, growing demand for video and graphics capability, and the desire for local analytics processing are driving an exponential demand for performance.

As usual, it is the responsibility of embedded – and now IoT – designers to balance these wants with size, weight, power, and cost (SWaP-C) thresholds. In addition, critical industries typically call for solutions that can be integrated into existing systems without extensive reengineering.

At the intersection of these requirements lies the proven, compact, and easily expandable PC/104 standard. Aside from its small footprint and low power consumption, close cooperation between component suppliers and board designers has resulted in a stackable architecture that has risen to the design challenges of each of the last three decades (Figure 1). Now equipped with next-generation I/O and support for modern processors, PC/104 is primed to upgrade the installed base of industrial systems with IIoT capabilities.

The evolution of PC/104 from industrial to IIoT

In keeping with Moore’s Law, the drive for more computational power, and therefore the need for faster data links, the PC/104 family of specifications has consistently incorporated new I/O technologies since its inception in 1987. As shown in Figure 2, this evolution has included the addition of PCI and PCI Express (PCIe) interfaces from the original ISA bus foundation.

The progression of PC/104 technology also coincides with rising bandwidth requirements in industrial systems, which now employ multi-core system on chips (SoCs) to support additional sensors and connectivity as part of the IIoT infrastructure. For designers looking to scale existing designs to support these capabilities, PC/104-Plus and PCI/104-Express provide ideal bridge technology.

PCI/104-Express, for example, supports not only PCIe, but high-speed interfaces like USB, SATA, and Gigabit Ethernet (GbE) as well. These interfaces, along with a higher level of signal integrity in the PCI/104-Express specification, ease integration of next-generation I/O peripherals and eliminate the need for re-engineering when adding modules to the stack.

And, with PC/104-compatible peripheral modules for almost any required capability, designers can move quickly from industrial to IIoT.

Powerful Peripherals Power PC/104 into IIoT

The ability to add functionality by stacking peripheral modules on top of a processor baseboard has helped PC/104 maintain its popularity over the years. In addition to providing a platform for new technologies, corner mounting holes and stack-through connectors on each board, excepting the base, means that legacy systems built on PC/104 technology can be upgraded easily – even across vendors.

For industrial engineers looking to transition their systems to IIoT readiness, today’s PC/104 peripheral modules offer features ranging from intelligent data acquisition to Wi-Fi connectivity to high-resolution imaging over GbE and more. Below are a few use cases that demonstrate how the compact and rugged PC/104 form factor can be leveraged to quickly add design capabilities.

Data acquisition

PC/104's flexible I/O architecture can be coupled with modern processors for high-capture rate data acquisition systems, with a high-speed camera and frame grabber providing a good example. Here, a PCIe/104 card can be used to facilitate multiple camera connections, while also controlling the high-speed bus. Such flexibility is possible because high-speed processing and specific peripheral circuitry can co-exist on the same PC/104 board.

One PCIe/104 data acquisition I/O card that integrates analog I/O technology with a PCIe interface is the E104-DAQ1616 module from Diamond Systems Corporation. The module supports all data acquisition functions, including analog-to-digital (A/D), digital-to-analog (D/A), digital input/output (DIO), and counters/timers. The board also supports the PCI-104 connector footprint as an option for communication with PCI-104 cards within existing stacks (Figure 3).

Gigabit Ethernet            

Aside from advanced processors, industrial applications like remote surveillance and traffic monitoring demand high-speed video packet streaming. Support for GbE, USB, and low power consumption in the PCI/104-Express and PCIe/104 deliver on these requirements in spades.

The LAN25222HR and LAN35222HR dual GbE modules from RTD Embedded Technologies provide GbE communications over the PCI/104-Express and PCIe/104 architectures, respectively. Driven by the Intel® 82574IT GbE controller, these modules each offer two GbE connections and 10/100/1000 Mbps RJ45 communications on each channel.

When deployed in video applications, the RTD boards perform tasks like data offloading and frame grabbing by providing desktop-level performance in a PC/104 form factor. Dual GbE interfaces, a host of other I/O, and onboard Trusted Platform Module (TPM) make it a potential centerpiece for connected industrial designs that require high levels of data integrity and security.

Meanwhile, WinSystems’ PX1-C415 PCIe/104 SBC based on the Intel Apollo Lake-I E3900 processor delivers dual GbE and a range of additional I/O through the OneBank expansion connector. The boards also include a trusted platform module (TPM), making it a seamless choice for small form factor, rugged Industrial IoT communications systems that handle sensitive data.

Wi-Fi controllers          

Wi-Fi is increasingly becoming the communication channel of choice for non-real-time applications in industrial environments like factory floors. Here again, PC/104's stackable architecture allows designers to seamlessly incorporate Wi-Fi modules or subsystems into existing industrial designs.

For instance, RTD Embedded Technologies offers PCI/104-Express and PCIe/104 Mini-PCIe card carrier modules for embedding Wi-Fi functionality into industrial applications, namely, the WLAN25203ER and WLAN35203ER. Both of these Wi-Fi solutions incorporate Atheros wireless LAN (WLAN) modules compliant with the 802.11a/b/g/n standards.

The dual-slot Mini-PCIe card carriers support both Type 1, Type 2, and universal PCI/104-Express and PCIe/104 expansion pinout options. Type 1 features PCIe x1 and x16 links with USB 2.0, while Type 2 supports PCI Express x1 and x4 links with USB 3.0 and SATA for the latest peripheral devices. The universal pinout supports PCIe x1 and/or USB 2.0.

The PC/104 and x86 partnership continues

At a time when the brave new world of graphics and displays is converging with IIoT designs, x86 processors with powerful CPUs and video processing capabilities are becoming increasingly prominent. These processors offer more compute performance, higher resolution graphics, and faster I/Os than previous-generation industrial CPUs while also consuming less power.

Originally designed with support for x86 processors in mind, PC/104 is already positioned to perform these workloads. VersaLogic’s PC/104-Plus Liger board is a case in point, featuring a seventh-generation Intel® Core processor based on the Kaby Lake microarchitecture. The mix of traditional I/O and advanced processing performance on the Liger offers the ability to upgrade legacy industrial designs while preserving connectivity with already-deployed modules or custom peripherals. The Liger also integrates a Trusted Platform Module (TPM) security chip directly onto the printed circuit board (PCB) that provides hardware-level security and prevents unauthorized access for sensitive industrial applications.

The existing design infrastructure around x86 processors and associated software complements PC/104’s versatility by enabling emerging functionality and maintaining compatibility with existing solutions. The combined ecosystem also offers a powerful platform on top of which industrial developers can customize their designs to meet specific requirements.

PC/104: Reload, don’t rebuild

A dense mix of I/O interfaces, wired and wireless connectivity mechanisms, and expansion options in a small form factor continue to enable PC/104 technology in embedded systems ranging from resource-constrained control systems to high-performance IIoT solutions. By providing support for advanced processors and high-speed interfaces while still delivering on the promise of reliability and long lifecycle operation, PC/104 developers can depend on their investment well into the future.

With an architecture that allows industrial designers to quickly deliver more performance and new functionality, there is no need to design new modules, source additional modules, or rebuild entire systems from scratch.

For organizations looking to take advantage of IIoT without massive investment or significant downtime, it’s time to get reacquainted with PC/104.

To join the Industrial IoT revolution, visit the PC/104 Consortium at www.pc104.org.

Jeff Milde is Executive Director of the PC/104 Consortium.

PC/104 Consortium

www.pc104.org