No matter where you believe industrial wireless networking is in terms of its adoption as part of today’s control systems, we can agree that wireless has altered the industrial network landscape. One obvious opportunity is that wireless now allows us to expand or extend the network to enable measurements not previously possible for many reasons.
In January, I asked, "What new measurements are now possible because we’re no longer constrained by cable?” But I discussed only field sensors. What other opportunities are possible, including near-real-time data from other parts of facility operations?
A number of organizations have provided examples of integrating the data collected by field sensors and field sensor networks into the larger control system. The ISA100.15 committee, in cooperation with the Fieldbus Foundation, developed the technical report, "Backhaul Architecture Model: Secured Connectivity over Untrusted or Trusted Networks,” which is incorporated into the foundation’s HSE backhaul standard, and is part of its Foundation fieldbus for remote operations management initiative.
Another such organization is the Wireless Industrial Networking Alliance. Its mission is to provide unbiased information and education about industrial wireless technologies and applications to accelerate the widespread deployment of wireless in the industrial market.
This requirement for cooperation extends beyond industrial wireless networks to any form of wireless communication. We need to remember that wireless is not constrained. As a result, we need to play nice with others, especially the commercial/consumer market, which is much larger in terms of dollars and devices and is also using the same spectra.
One example of a potential crossover between consumer and industrial markets is the use of Google glasses with safety lens for mobile plant workers in non-IS environments to access process information or reference manuals for the task they’re performing. Accessing this kind of data will require integrating and sharing the bandwidth between these two levels of networks, and increasing cooperation between the control and IT communities.
Some organizations with which I have worked are somewhat proactive in managing the wireless spectrum in their facilities. They create drawings, similar to area classification drawings, for the entire site, indicating which group or groups have "ownership” for specific portions of the ISM band in certain parts of the plant. For example, in the processing facility, the 2.4-GHz spectrum or constrained channels within the spectrum are available for process control/field sensor networks, while the 900-MHz spectrum is for the associated backhaul, and 5.8 GHz is for IEEE802.11 users (typically IT). LTE/4G is also now becoming more widely used within control systems, especially for SCADA applications.
Another example of the types of challenges with spectrum management, now underway in the European Union, is ETSI EN 300 220-2 "Electromagnetic Compatibility and Radio Spectrum Matters (ERM); Short Range Devices (SRD); Radio equipment to be used in the 25-MHz to 1,000-MHz frequency range with power levels ranging up to 500 mW; Part 2: Harmonized EN covering essential requirements under article 3.2 of the R&TTE Directive” (bit.ly/SWpi2n). This has a requirement for any device above 10 mW to listen before talking, which will affect all the existing field sensor network standards, while also having a potential cybersecurity impact.
The industrial network certainly can now be expanded to reach almost anywhere, however, the price is complexity and competition for a limited resource. We are coming closer to being able to expand control systems to make any measurement, anywhere, anytime — in other words, the Internet of Things.