- By Jack Smith
- June 29, 2023
Industrial PCs differ from consumer PCs in ways that are vital to industrial automation applications.
Possibly more similarities than differences exist between consumer/commercial computers and industrial computers. Industrial PCs (IPCs) leverage many of the advances that come from the consumer tech world but add the software, programming, determinism, and connectivity essential to industrial applications.
“From increased memory to the exponential growth of processing power described by Moore’s Law, industrial controls only stand to benefit from the evolution of PC technology. But IPCs must be hardened to withstand harsh production environments,” said Eric Reiner, IPC product manager, Beckhoff Automation LLC.
“Commercial computers are often far more powerful and cheap, easier for POC [proof of concept], and AI [artificial intelligence] applications,” added Oliver Wang, product marketing manager, Computing Division at Moxa Americas Inc. “But they are problematic when deploying to scale in industrial environments [due to] reliability in supply and hardware, or additional support for industrial use cases, industrial voltage/certs, and the like.”
IPCs are similar to commercial PCs in terms of receiving, storing, and processing information to perform operation sequences based on software instructions. Hardware components such as motherboard, CPU, RAM, expansion slots, and storage media are also similar.
However, IPCs differ from consumer PCs in terms of ruggedness, reliability, performance, compatibility, expandability, and long-term availability. Perhaps the biggest differentiator from commercial PCs is that IPCs have industrially hardened exteriors (Figure 1) and, therefore, offer an advantage over personal computers in industrial environments because they enable equipment that can withstand temperature fluctuations, noise, vibration, and other industrial harshness.
IPCs must operate in harsh, aggressive, and dirty environments. Operating in tough conditions, industrial PCs can withstand such factors as shock and vibration, which can be detrimental to commercial PCs; thermal
extremes, which can affect performance and hardware lifespan; dirt and humidity; IP rating; and electromagnetic interference (EMI), which is common in industrial environments.
IPC-based control systems increase connectivity capabilities for industrial applications. They also provide powerful, flexible, and cost-effective control. IPCs typically operate in real time and are deterministic. For example, highly accurate and deterministic cyclical updates enable increased accuracy for coordinated motion control and data samples at precise time intervals. In contrast, programmable logic controllers (PLCs) typically offer scan rates in milliseconds, as opposed to the IPC’s microsecond level.
“IPCs are definitely not direct replacements for PLCs, but the younger generation seems to be taking to the PC approach and are finding lower barriers to entry,” said Wang. “Consider this: It’s clunky and unresponsive and expensive to use an app on your iPhone to change the channel of your TV versus using the purpose-built remote control. Purpose-built controllers and devices are often superior because they are designed to do that specific thing.”
IPC-based control systems provide benefits for industrial applications, including performance, decreased costs, and an increased system lifecycle. IPC-based control systems can integrate faster, with more powerful processors than a hardware PLC. Many machines and equipment benefit from centralized control, while there are cases where decentralized control is advantageous. In general, it is most beneficial to access all software and data from one central location and use one central communication method for all devices on the control system.
When a PLC becomes obsolete, the software may also require upgrading. In an IPC-based control system, the end of a processor’s lifecycle does not mean the system architecture or software becomes obsolete. By incorporating more functionality into the software and running that on an IPC, users can replace the aging IPC with a new one without any changes to the rest of the control system—including the software. Automation programs and fieldbus configurations can be downloaded to a software system on the new IPC with no need for code changes.
The evolution of industrial control technology has sometimes accentuated differences between PLCs, programmable automation controllers (PACs), and IPCs. Other times, it has blurred them. But there are some general differences.
“PLCs are designed with a single processor to execute machine control logic deterministically,” said Reiner. “They were the evolutionary step immediately following hardwired relays. Ladder logic is the prevailing programming language for traditional PLCs. They typically communicate just one protocol, with any additional fieldbuses or protocols requiring an additional piece of hardware. PACs can use multiple processors per rack for higher performance. They accommodate more programming languages and even some third-party software for increased functionality. However, the system is still fairly closed compared to true PC-based control.
More industrial users are taking greater control over software. “They are looking for ways to use Linux, cloud, and PCs to hedge against reliance on traditional specialized, purpose-built HMIs [human-machine interfaces] and proprietary technology to stay competitive and flexible,” Wang said.
He adds that many of these applications are in the power and transportation sectors. There are also applications in edge computing for Modbus data acquisition and aggregation in renewable energy and energy storage, as well as those that exist for “onboard rail and bus for fare collection, GPS-based fleet tracking, onboard video surveillance, and machine learning-based visual track inspection.”
“PC-based control was foundational for Beckhoff,” said Reiner. “We’ve been successfully executing applications with IPCs since the early 1980s. The first OEM [original equipment manufacturer] to integrate Beckhoff controls was a woodworking machine builder, but we have decades of experience using PC-based control in just about every industry: packaging, fabrication, assembly, logistics, test and research, etc. Now, a single CPU can handle machine control logic, vision, safety, HMI, and much more, compared to the many single-purpose black boxes required in legacy architectures.”
“Automation in a factory setting is definitely a key use case for industrial computers, but our clients are using our hardware for a nearly limitless number of applications,” said Darek Fanton, communications manager at OnLogic. “Industries we’re seeing on the rise now include energy management, smart cities and buildings, smart agriculture, mining (Figure 2), autonomous vehicles—from self-guided warehousing robots to autonomous tractors and concierge robots that move items around a hotel, hospital, or mail room—and medical devices. And, in addition to SCADA applications, our systems are used for IoT [Internet of Things] gateway applications, digital twin setup, and model building, which is essentially edge to cloud communication, data logging, edge servers, and the like.”
Fanton added that industries having high regulatory requirements and standards are turning to IPCs that can often be standardized and made available with longer lifecycle commitments “to avoid costly and time-consuming recertification that can crop up when consumer PCs go through a generational revision.”
Software and operating systems
According to Wang, the continued trend is to enable industrial users to build their own tailored solution on a “host device” or IPC-based platform. “The impact of supply chain and cybersecurity concerns is still developing. Best practices for secure supply chain, secure boot, and OS [operating systems] are new challenges for both manufacturers and users,” he said.
“In the past, many believed PLCs were more secure and deterministic, but this has not stood the test of time,” continued Reiner. “PLCs, PACs, and IPCs all use a modified version of commercially available OS and BIOS rather than the proprietary firmware of yesteryear. The key differentiator is that IPCs provide greater openness to best fit [users’] requirements for flexibility in programming, connectivity, and integration with devices from other vendors.”
Implementing IIoT and Industry 4.0 functionality with IPCs is the logical next step to establishing more connected enterprises. PC-based control provides the most logical control platform with an unobstructed migration path to add higher levels of connectivity today or at any time in the future, even if users are not ready to embrace IIoT and Industry 4.0.
Historically, adding IoT communication with PLCs has become increasingly difficult. Doing so typically entails adding third-party IT hardware and software to make it work. However, this type of connectivity has been possible with PC-based control, even before many modern buzzwords emerged. Internet and Ethernet connectivity has been built into PC-based control platforms for decades, which has enabled connectivity with little or no additional hardware.
“More companies are adding IoT capabilities out of the box as a standard feature for machines and systems,” said Reiner. “With the inherent open connectivity of IPCs, this is no problem. Our controllers can connect to the cloud or enterprise level securely and without the need for an additional IoT gateway."
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