If you ask the technology professionals who are focused solely on Industry 4.0 and digital transformation, they may tell you that the data bus is dead.

Why would they say this? They’re likely assuming that data buses are no longer relevant as IIoT moves into the industrial space, using industrial Ethernet networks to connect sensors, instruments and other devices with the right applications.

If you ask the people who work in these industrial environments every day, however, you’ll likely hear a much different story: Data buses are still very much alive and thriving—even in plants that are integrating IIoT.

What is a Data Bus?

Serving as a transportation system for data, a data bus sits inside a computer or device to distribute and manage real-time data in intelligent distributed systems.

The first data buses were introduced in the late 1950s, but they’ve come a long way since then. Newer data buses can handle high bit rates and large amounts of data. They manage data flow by moving information to and from the memory or CPU acting as that particular device’s “engine.” A data bus brings applications and devices together so they can work as a completely integrated system.

How Are Data Buses Being Used Today?

The type of network deployed within a manufacturing space ultimately comes down to the devices in use—and what those devices can support (whether it’s Ethernet or something else). In some cases, data buses are powering IIoT without the use of Ethernet connectivity.

Because not all end devices are embedded with Ethernet capabilities, they aren’t able to transmit data over a cable. That’s where a data bus comes into play. We see this happening in especially large processing facilities where the transition and conversion from analog to digital is much slower going and requires a cautious approach. In these environments, unexpected network downtime can lead to dangerous fires and explosions. Over the years, data buses have proven they have what it takes to help ensure the non-negotiable uptime required for these types of plants.

Data buses are also being used in industrial spaces that don’t necessarily need or benefit from IIoT. Although there’s a strong trend toward adopting networking in manufacturing spaces like processing facilities, these networks aren’t necessarily IIoT networks. Legacy networks, like FOUNDATION fieldbus and PROFIBUS, have been the workhorses of the industry for a long time, and they’re still growing.

While there’s no doubt that IIoT is gaining traction, end devices are still more likely to be connected to a process network vs. an IIoT network due to a process network’s potential range and proven reliability over time.

Because traditional data cable distance is limited to 100 m (328 ft), it’s difficult to achieve cable lengths beyond this distance to connect devices. We see this often in distributed process sites. Some data buses, including FOUNDATION fieldbus, can reach as far as 10,000+ ft—a much longer distance than can be achieved with a data cable.

Data buses continue to be deployed to support low-cost distributed networks as well, such as PROFIBUS and DeviceNet networks.

We were curious to see whether we had any data to support the continued use of data buses—despite the proliferation of IIoT—so we took a look at some of our own sales information, including Belden fieldbus and PROFIBUS cable sales over the past few years.

As expected, Belden has seen strong growth across legacy networks, with sales of FOUNDATION FIELDBUS, PROFIBUS, ProfiPA, and RS-485 all indicating robust progress. It’s no surprise that the information we uncovered aligns with the fact that data buses are still very much in use today—and likely will be for several years to come.

Want to learn more about Belden’s comprehensive line of fieldbus cables, which are designed to support data buses and withstand the destructive conditions found in industrial environments?