Industrial wireless monitoring and sensing


Pervasive wireless network

Facility operators often face aging, legacy equipment that may be “un-instrumented,” and data acquisition on performance and maintenance may be natively impossible. Being able to retrofit ad hoc instrumentation and communicate to gather data and metrics can allow for better operational monitoring and maintenance planning and reduce downtime. One solution is to develop ad-hoc (off- the-shelf) modules for sensor types (humid, temperature, vibration, pressure) to allow rapid deployment of wireless-based sensors to gather relevant data. This allows ad-hoc, short-term, or emergency surveillance of problem devices. Plus, it allows a modular approach to wireless sensor measurement in an aging facility environment without large-scale digital equipment upgrades.

Beyond the delivery of voice over Internet protocol (VoIP) and mobile worker/data applications, the availability of a pervasive wireless network within the facility allows deployment of low-cost sensors and meters for tactical or short-term operational needs. A “bug-like” approach for the deployment of multi-sensor devices that is specific to the operation’s needs should be used.

For example, if a faulty motor or pump is suspected, a camera, vibration sensor, and hall-effect monitor can be attached to the housing. In today’s market, the sensor takes three minutes to assemble the modules in the “plant shop” and one minute to provision on the network.

Cohesive reference architecture

One of the best ways to avoid wireless technology obsolescence, ensure a long system lifecycle, and maximize system utility is to select and deploy wireless infrastructure in the context of a cohesive reference architecture. A reference architecture’s chief function is to provide a baseline roadmap related to interfaces and capabilities of related technology systems and business processes for legacy and planning perspectives. Investing the energy and effort in development of a well-thought-out reference architecture provides several key benefits. These include ensuring equipment compatibility, adherence to and compliance with evolving standards across the enterprise, realization of long-term return on investment goals, and optimal planning of capital expenditure spending.

In an industrial setting the major components comprising a reference architecture typically include field instrumentation, communications, storage/analytics, and presentation/visualization. There are dozens, if not hundreds, of field devices that can be connected using one or more wireless technologies. Capturing field devices in the reference architecture provides an easy method for managing the multiple interfaces that need to occur between field and communications devices. Similarly, management of the interfaces between communications networks to the analytics/storage and presentation/visualization layers is also important to capture in a reference architecture. This ensures that higher layer factors including communications protocols, application programming interfaces, interface libraries, and other critical communications functions are well understood and accounted for during the wireless technology selection process.

Embracing wireless

Although not without challenges, wireless solutions can act as a common enabling technology. They can:

  • Provide ubiquitous communications capabilities
  • Offer cross-operational value and utility
  • Deliver common IP access using standards with robust cyber security
  • Reduce lead time and costs associated with wired cabling. 

Doug Bowers, SAICOn many projects, doing nothing is not an option, so the wireless solution acts more as a risk management policy. Plus, a strong communications foundation can address many challenges facility operators face during process transformation.

- Douglas Bowers is a senior project manager at SAIC. He has more than 15 years of experience in system integration for communication and network systems, identifying requirements, writing specifications, design, testing, and delivery, including rapid prototyping and development of sensor systems for industrial environments. Edited by Mark T. Hoske, content manager, CFE Media, Control Engineering and Plant Engineering,


Bowers presented in a Control Engineering industrial wireless webcast. Learn more at links to related coverage.

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Jonas , Singapore, 12/23/13 09:20 PM:

For wireless sensor networks in process applications, it looks to me as if the industry is narrowing it down to IEC 52591 (WirelessHART) technology based on IEEE 802.15.4 radio with mesh topology. Broadband applications use IEEE 802.11 (Wi-Fi). This narrowing down makes wireless infrastructure deployments easier than it was in the past.

I agree plants need to be aware of the challenges of wireless sensors in an industrial environment and the best practices for radio frequency (RF) communication in environments full of steel such as vessels, pipe racks, and structural steel found in a plant. A full mesh topology excels in this environment.

I agree existing plants lack on-line data to support diagnostics; the data is usually collected manually. I believe this is because most plants were built years ago with only a minimal amount of instrumentation necessary required to safely operate the process, because 4-20 mA and on/off signals are expensive due to the large amount of cable, conduit, junction boxes, cable tray, installation labor, marshalling cabinets, system cabinets, and I/O cards etc. Improving process unit utilization, energy efficiency, reducing maintenance costs, and mitigating safety and environmental incidents to stay competitive requires additional automation, but the necessary data is not available. These are missing measurements. But ageing plants can be modernized with wireless.

I agree implementing wireless sensor networks create benefits across multiple areas. For instance, process equipment diagnostics (commonly referred to as ‘type 4’ diagnostics) improve process equipment reliability, reducing downtime, while minimizing maintenance cost and more effectively scheduling turnarounds by continuously diagnosing which equipment require maintenance and which don’t. Potential equipment includes heat exchangers, pumps, blowers, air cooled exchangers (fin-fans), unmonitored compressors, and cooling towers etc. Furthermore, the equipment diagnostics, for instance on equipment onboard a FPSO or FLNG vessel, or a platform etc, can be accessed remotely by experts from an onshore center of operations in an integrated operations (iOps) scenario. Another area benefitting from modernization is automatic energy monitoring to drive energy conservation measures for generation, consumption, and loss to improve energy efficiency thus reducing cost.

A third area of benefits is automatic HS&E monitoring to reduce personnel exposure (reduced operator clipboard rounds), detect hazards, record emissions, and provide operators increased situational awareness thus benefitting health, safety, and environmental as well as for associated regulatory compliance should also be part of modernization.

A primary layer of automation already exists in plants using hardwired or fieldbus signals to the control and safety systems covering functions “on the P&ID”. A new second layer of automation uses wireless sensor networks mainly to the asset management system for monitoring of missing measurements with pervasive sensing going beyond the P&ID for maintenance, reliability, HS&E, and energy personnel in offices beyond the control room. By eliminating wires, deployment is accelerated and low risk, possible during a turnaround or even while the plant is running.

Wireless sensors and software enable plant personnel to become more effective

I also agree that a wrong approach to wireless infrastructure architecture can create huge cost and dissatisfaction. For instance, I personally believe use of a full multi-hop multi-path mesh topology is a critical success factor for high reliability as well as for easy and low risk deployment. Other topologies may require costly backbone router infrastructure which is disruptive to install.

A modernization guide is available to help engineering from justification and scope, to design, installation, and handover.

I agree that until now, aging infrastructure is expensive to instrument, monitor, and maintain. However, WirelessHART changes this. The WirelessHART mesh network reduces the cost and risk of deploying sensors around an aging plant.

Interestingly, most of the new data does not go to the control or safety system operator consoles in the control room. Most additional data goes beyond the control room, for instance to the maintenance and reliability office, presented as KPI and equipment dashboards, not as an animated P&ID. To avoid the data “fire hose” the raw data from wireless instruments is aggregated in essential asset monitoring software with pre-engineered modules for pumps, heat exchangers, air cooled exchangers, cooling towers, blowers, unmonitored compressors, filters & strainers, as well as pipes & vessels. Multi-parametric algorithms embedded into the software provide easy-to-understand process equipment diagnostic information.

Once wireless sensor networks have been deployed plant-wide, the plant is prepared to quickly and easily add more automation as needed in the future to meet shifting and evolving industry demands.
New plants should be built including wireless sensor networks from the very beginning. Do not design in traditional operator rounds.

I agree that the market is flooded with proprietary wireless network solutions which would result in fragmented point solutions. The IEC 62591 (WirelessHART) standard finally provides a single common network infrastructure, a “systems approach” for all applications: steam trap monitoring, relief valve monitoring, and process equipment monitoring and many more, eliminating needs for multiple proprietary wireless solutions.

Personally I totally agree that planning maintenance for aging legacy equipment is difficult because they are “un-instrumented”. Being able to deploy a second layer of automation based on WirelessHART instrumentation and communication can allow for better operational monitoring and maintenance planning and reduce downtime.

There is no need to migrate or upgrade the control system to deploy a second layer of automation based on WirelessHART. The gateway interfaces with modern as well as legacy DCS and PLC using standard backhaul protocols. Moreover, most of the data may not go to the control system, but direct to asset management system or other applications.

I like the expression “bug-like”. The sensors are wireless and are stuck onto equipment etc. everywhere, snooping on these equipment, overhearing what’s going on, reporting back their status. One reason wireless sensors are low cost is because they are non-intrusive. There is no wiring for power. No wiring for signal I/O. That is, electrical installation is non-intrusive. In many cases non-intrusive mechanical installation is also possible: there may be existing thermowells or tapping points for installation of temperature sensors and pressure transmitters. Clamp-on surface temperature transmitters can also be used. Pressure transmitters can be installed where pressure gauges previously were mounted. Valve position feedback bolt onto hand operated valves like bypass valves. Vibration sensors can either be screwed on the outside, glued on, or even use a magnet. Acoustic transmitters for monitoring of valve leaks, relief valve activation, and steam trap health simply strap onto the outside of the pipe using hose clamp. In many cases new process penetrations need not be drilled, cut, or welded. That is, not only low installed cost, but low installed risk.

Learn more from this blog:

Indeed wireless sensors are very fast to install and provision/commission.

IEC 62591 (WirelessHART) is the international standard for wireless in process applications. It is supported by multiple vendors ensuring wireless transmitters and gateways from these vendors are compatible and interoperate. The plant can deploy a single cohesive network architecture used for all their wireless sensors maximizing the use of the system. Because it is a standard, technology obsolescence is staved off. WirelessHART devices are tested and registered for compliance with the IEC 62591 standard.

The interface between the WirelessHART networks and the control system and asset management system is using the HART-IP, Modbus/RTU, Modbus/TCP, or EtherNet/IP protocols in any combination. OPC is often used too as a software interface, but proprietary APIs are not used.

All these improvements are possible without adding any control loops and without migrating the control system.

WirelessHART enables existing sites to be modernized & sustained in ways previously not possible, benefitting both operations and maintenance. Start by requesting the user’s guide to how to modernize and sustain an old plant using a second layer of automation for pervasive sensing of missing measurements found beyond the P&ID. The guide covers the modernization process from justification and audit to commissioning and handover. The guide can also be used for new projects to deploy plant-wide wireless infrastructure, to make sure the new plant is not built to be run & maintained the old way.

Plant modernization is a new EPC business model. EPCs can go back to all the plants they have build over the past 20-30 years and offer all the above plant modernization by means of a second layer of automation based on WirelessHART.