Industrial designers continue to choose PC/104 for both traditional and cutting-edge applications

Reliability and performance still matter for industrial embedded computing applications, which is why the PC/104 standard remains the first choice for those solutions requiring small form factors that can operate reliably in harsh industrial environments. While designers still choose PC/104 for rugged industrial applications, they are also opting for the time-tested architecture in newer technology applications such as artificial intelligence (AI), machine learning (ML), and the Industrial internet of Things (IIoT).

“PC/104 has a strong presence in the industrial market,” says Stephen St. Amant, president of the PC/104 Consortium and director of marketing for RTD Embedded Technologies (State College, Pennsylvania). “It was that way when our first ISA-based specifications were adopted, and it remains so with our latest PCIe/104 specs. From its beginning, PC/104’s goals were to create compact, industrial embedded PCs suitable for harsh environments. Their compact footprint, stackable buses, and inherent ruggedness helped the PC/104 specs to earn a reputation for reliability and overall value.”

Since the consortium’s founding in 1992, PC/104 has been “a favored form factor for embedded solutions in markets where vibration, fluctuating power, granular debris, and round-the-clock use can’t be allowed to interrupt critical application uptime,” says Roy Keeler, vice president of branding for the PC/104 Consortium and senior product and business development manager, aerospace and defense, for ADLINK Technology (San Jose, California). “PC/104 provides a unique set of attributes that offer particular value in applications that require compute performance and low power consumption in a remarkably compact form factor – all while appealing to constrained budgets.”

Some would say PC/104 wasn’t just designed for rugged industrial market applications, but for rugged applications across multiple arenas.

“The term ‘Industrial Market’ is becoming a bit blurred, in my view,” says Flemming Christensen, the PC/104 Consortium vice president of technology and managing director of Sundance Microprocessor Technology (Chesham, Buckinghamshire, England).“Historically, then PC/104 was covering all sectors, like ‘automation,’ ‘makers,’ ‘military,’ and ‘space,’ and the ‘industrial’ category is/was defined with an embedded processing solution that would work below 0 °C and above 50 °C, because not all did! The requirement for wearables meant that we expect our phones to work in rain, snow, sea, and desert, so almost all components are now ‘industrial-compatible’ in terms of temperature.”

“For military, medical, automation, and a range of similar verticals, PC/104 delivers a wealth of proven benefits,” Keeler notes. “The form factor’s stackable design allows for excellent scalability mixed with compute density and x86-based programming ease. For embedded applications where size, weight, power and cost (SWaP-C) restraints are key, PC/104 can provide the cost-effective, capable solutions organizations need to support legacy and forward-looking efforts simultaneously.”

Choosing PC/104 for today’s solutions

Historically, PC/104 clearly has been a leader and continues to be today for similar reasons.

In many cases, the reasons are the “same as always, although there are many more options for embedded solutions now, compared to 25 years ago when PC/104 hit the market,” Christensen says. “Hundreds of different ‘computers-on-module’ and ‘systems-on-module’ [are out there], but the PC/104 is only module that also adds ‘rugged’ and ‘stackable’ for easy upgrade and service.”

“No one standard is all things to all applications,” St. Amant explains. “Where PC/104 excels, and why we see it so often as a choice for customers, lies in its small size and its inherent ruggedness. On top of that, PC/104 has excellent size to power and performance ratios. Add in modularity and a thriving ecosystem of off-the-shelf products, and PC/104 is a compelling choice. Many PC/104 manufacturers offer five- to seven-year guaranteed product availability; some, even longer. For large-scale industrial operations, that extended availability is a big win. While temperature range is not part of the PC/104 specifications, we know that many PC/104 manufacturers target operational ranges from -40 °C to +85 °C and beyond.”

Obsolescence-management life cycle challenges also drive users toward PC/104 technology. “The main reason is the option to replace or upgrade a single board, as it gives options to expand the system later or redesign part of system, due to obsolescense of part/boards/supplier,” Christensen notes.

“We see PC/104 boards and enclosed systems supporting projects in the Industrial internet of Things (IIoT) and in the larger Industry 4.0 movement. PC/104 is being used in mining, farming, asset tracking, fleet management, material handling, geological exploration, and more,” he continues. “As broadly as one can define ‘industrial,’ that’s about the same breadth that you’ll find in the way PC/104 serves the market.”

Looking forward

“The backbone of PC/104 is the low-cost stackable PCIe bus structure to replace a typical large backplane in a ‘conventional’ industrial rack,” Christensen says. “The consortium has tested and validated the connectors to above Gen3 of PCIe, hence there’s plenty of performance left for decades. A working group has started on ‘Next Gen,’, but the consortium is not in a rush to push new specification, as why fix something that is not broken.”

PC/104 solutions will benefit applications such as industrial automation, monitoring, predictive maintenance, and cloud connectivity as they are on the rise, St. Amant says. “They have been for years, [and] PC/104 tracks right alongside these trends.”

Artificial intelligence (AI) and machine learning (ML) technology are creating paradigm shifts in every industry – including industrial – and PC/104 designers see this as a natural fit for their reliable solutions.

AI will be huge: Look at its potential to transform industrial preventative maintenance, Keeler says. “One example might be air-flow-through manufacturing-floor ventilation conduits. Sensors can detect vibrations and turbulence. Cycled through edge-based monitoring systems, analysis of this data can signal early-warning indicators that trigger maintenance before unforeseen ventilation failure forces factory production downtime. Alternatively, consider intelligent monitoring of robotic assembly tools. Input feedback may range from vibration levels to output-speed analysis to camera-based confirmation of part placement. In such situations, edge intelligence may spot faults before cloud-based solutions would, yielding fewer failures, higher accuracy, and less disruption further down the production line.”

PC/104 will be a key enabler of AI in industrial applications and other markets, he continues. Globally, PC/104 represents a billion-dollar industry. “We expect PC/104 to continue playing an important role in military, medical, automation, and other vertical fields where SWaP constraints thrive and the need for edge intelligence continues to climb,” Keeler says.

PC/104 offerings

An offering in this space is the RTD SSD24200HR high-speed SSD storage module based on the M.2 format. Two M.2 Socket 3 interfaces leverage the PCIe/104 Type 2 connector, enabling the inserted devices to use a SATA link for data transfer or a PCIe x4 link. The SSD24200HR can be used as a high-speed storage solution alongside RTD’s new 25 MS/sec data acquisition module, where continuous data from four channels can simultaneously be written to SSD via the NVMe connection without losing any data. (Figure 1.)

Figure 1: The RTD PC/104 entrant for use in industrial applications is the SSD24200HR high-speed SSD storage module based on the M.2 format.
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ADLINK offers the CMx-SLx board; the base model offers the sixth-generation Intel core processor i3-6102E (2 cores, 1.9 GHz, 25W TDP), with variations available. Graphics arrive via Intel’s ninth-generation integrated core, which features ample video decode acceleration and simultaneous triple display output across HDMI, DisplayPort, and LVDS. ADLINK supplies 8 GB or 16 GB of surface-mounted DDR4-ECC RAM and a range of onboard SLC- or MLC-based SSD storage from 8 GB to 64 GB. (Figure 2.)

Figure 2: The CMx-SLx from ADLINK is aimed at users who need high-level processing and graphics performance in a long product life solution.
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Sundance integrates Zynq SoC with quad 64-bit Arm CPUs on a PC/104, as part of, running Linux with flexible I/O from the FPGA [field-programmable gate array]. The company then added a low-cost I/O-like four-layer circuit board that can be full of I/O connectors. It is also designed with “power-over-Ethernet,” as the entire solution takes less than 15 W. Sundance officials say they believe this will open new doors for industrial applications, like robotics. This platform will actually be integrated into an autonomous robot for vineyards (see (Figure 3.)

Figure 3: Sundance’s offering is designed with “power-over-Ethernet” for a draw of less than 15 W.
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Apex Embedded Systems (Monona, Wisconsin) recently introduced a 3.3-volt version of its “Tracer” high-current PC/104 digital I/O and counter/timer module. The part provides 48 lines of 8255-compatible general-purpose I/O and is designed to operate over a wide temperature range (from -40 ºC to +85 ºC). Apex also offers a Tracer version it calls “any voltage,” which can deliver voltages from 1.8 volts to 5 volts.

Another PC/104 solution in the industrial arena is the PCAN-PCI/104-Express FD from PEAK-System Technik (Darmstadt, Germany), which enables connection of PCI/104-Express systems to CAN and CAN FD buses for use in modular embedded systems such as industrial PCs.

For its part, WinSystems (Arlington, Texas) offers its PX1-I416 module, which adds Mini PCI Express expansion capability to embedded systems with PCle/104 OneBank expansion. This part is aimed at maximizing use of a host platform while giving the designer access to myriad commercial off-the-shelf (COTS) I/O modules from a multitude of suppliers.

The ConnectTech PC/104-Plus to Mini PCI adapter allows users to install a Mini PCI card, such as an IEEE 802.11 wireless LAN card, into a standard 3.3 or 5V PC/104-Plus stack. Equipped with a passive PC/104 stack-through connector, the card can be installed in a PC/104-Plus stack without interfering with the signals of PC/104 cards located above or below. (Figure 4.)

Figure 4: ConnectTech’s PC/104-Plus to Mini PCI adapter can be installed in a PC/104-Plus stack without interfering with other PC/104 cards’ signals.
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