Wireless Automation Technology Automation Technology Moves Towards The Wireless Era
In the last few years, the emergence of standards-based solutions for wireless communications has initiated a radical change. Also, Novel-distributed signal processing algorithms, energy-efficient medium access control and fault-tolerant routing protocols, self-organising and self-healing sensor network mechanisms etc., have contributed immensely in growth of the wireless technologies on industrial front.
Sensor networks for monitoring and control are not a new concept. Wired implementations have found widespread use owing to their simplicity and low cost nature. On the other hand, the use of proprietary wireless networks has historically been limited to just a few niche applications. Over the last few years, the emergence of standards-based solutions for wireless communications has dramatically changed the market‘s perception of the technology.
Of the many benefits that a standards-based solution offers, a key advantage is interoperability. The emergence of standards such as IEEE802.15.4 and ZigBee, which are targeted at RF applications requiring low data rate, long battery life, and secure networking, have equally changed the market‘s perception of wireless technologies for sensor networks. The key catalyst for this growth is the availability of integrated chip solutions at market affordable prices.
Getting Started With Wireless Automation: What are the Industrial WLAN Requirements?
Industrial WLAN requirements differ from those originating from within enterprise and home environments. These include:
- Strict delay requirements: For example, enterprise VoIP applications can tolerate delay latency of up to 150 ms and up to 1 per cent data corruption in transit due to adaptive play-out control and error concealment algorithms. In contrast, the delay requirement for industrial Ethernet is 10 ms for field device applications, and below 1 ms for motion control applications. In addition, minimising delay jitter is also important for periodic control communications.
- Deterministic performance guarantee: In industrial networks, runtime performance degradation is not an option for missioncritical applications. This requirement is also enforced during device roaming, which leads to the requirement for real-time handover.
- Support for large and varying number of devices: With industrial applications one WLAN access point is likely to serve a large number (in the order of hundreds) of field devices and sensors. Supporting large and varying number of clients in the context of an industrial WLAN can overload the MAC protocol.
- Network security: Industrial WLANs used in factories must meet industrial safety and security regulations. These requirements include premises protection, and detection of rogue clients and access points.
- Network commissioning: Industrial networks place special emphasis on network commissioning, because runtime network failure is unacceptable. For industrial WLANs, the commissioning requirements include auto-commissioning where a large number of devices are to be used, and the execution of radio planning and assisted site surveys.
Wireless control networks are expected to revolutionise the whole process automation industry, insiders believe. But, despite single big installations the implementation seems to progress only slowly. A new study by ARC casts a spotlight on an exciting technology and explains why standards and legislation can be both driving force and ball and chain. More in Wireless Automation yet Has to Live up to Its True Potential
In general, these industrial WLAN requirements may serve as basis (not limited) for selection of technology, protocol and topology from the available wireless options. Learn more about the market for wireless automation technology on page 2!
Novel-distributed signal processing algorithms, energy-efficient medium access control and fault-tolerant routing protocols, self-organising and self-healing sensor network mechanisms, etc., have contributed immensely in growth of the wireless technologies on industrial front. Recent developments like ZigBee, IEEE 802.15.4, Wireless- HART and ISA SP100 have provided indeed some exceptional boosts to this rapidly growing novel technology for some critical applications development.
Market Survey Reports Annual Growth Rates of 25 Percent for Wireless Technology
Technology consultants VDC Research Group (USA) recently completed a worldwide market study on wireless and wireline industrial networking infrastructure products, which includes a user technology opinion survey.
The global market for the industrial wireless networking infrastructure products under study is expected to increase at a compound annual growth rate (CAGR) of 25.4 per cent from $299.3m in 2007 to $928.1m in 2012. Strong growth rates are forecast for each product category. Asia-Pacific is being Key Growth Driver.
- Main reasons for these wireless growth expectations include attractiveness of mobility in industrial facilities, increasing awareness of wireless technology and the benefits associated with it, increasing trust in wireless networking and perceived ease of implementation.
- Average selling prices for all these wireless products are expected to decline globally through 2012.
From Standards to Technologies: Wireless Network Types
The IEEE 802.11 family of standards accounted for the largest share of 2007 shipments, operating in the 800/900MHz and 2.4GHz bands. There is also a shift toward use of lowpower networks. The shipment share for the IEEE 802.15.4 family of standards, which includes Wireless HART, ISA SP100.11a and ZigBee, is expected to increase.
Sometimes, pure is best. But sometimes, mixing does the trick - A combination of network technology sometiomes works best... more on page 3!
IEEE 802.11 products operate in the 2.4GHz and 5GHz frequency bands, which allow for a high data throughput and a range of up to 100 metres. However, industrial applications in large facilities, such as oil and gas fields or water/wastewater treatment plants require longer distances. Additionally, signals at these higher frequencies are more susceptible to physical interference such as pillars, machinery and walls.
The choice between a standard such as IEEE 802.11 and networks operating in lower frequency bands comes down to the application. Users needing to transfer large amounts of data, in short time periods, at relatively short distances, may find that IEEE 802.11 fits their needs best. Longer range applications may require lower frequency networks.
Mix it to the Max! A Combination of Wireless Networks Sometimes Brings Best Effects
In many instances, a mix of networks works best, with lower frequency bands used at the sensor or field level and IEEE 802.11 elsewhere. The green curve (Refer Figure 2) illustrates the exponential decrease in unit price, while the orange curve shows the exponential increase in unit shipments. Today, one can get products with ten times the performance for one-tenth of the cost. Such impressive price-performance improvement and massive shipment volume lead to lowcost and stable supply of WLAN components.
endorsed by huge rise in demand and enhanced CAGR of the manufacturer organisations shipping wireless instruments in recent time.
But where to use wireless automation technology? More on page 4!
Classification of WSN applications:
Asset Protection Applications for Wireless Technology:
- Monitoring of bearing pressure, pump pressure, vibration, corrosion, safety relief valve emissions for more effective regulatory compliance
- Wireless vibration sensors for real-time view of rotating equipment health
- Automated status checking of previously unmonitored equipment such as on/off valves, pumps etc.
Automation for Process Monitoring Applications:
- Monitoring of - crude oil, gas plant, LDAR, offshore gas, oil production, oil well, pipeline pressure, pressure gauge, relief valve (LDAR), remote vessel pressure, rupture disc (LDAR), tank level etc.
- Environmental surveys, inventory management
- Process control (PID), supervisory control
- Elimination of clipboard rounds, gaining valuable insight into process
Safety, Health and Environment Applications:
- Location monitoring, mustering solutions, mobile operators and maintenance, field asset maintenance and mobility
- Monitoring safety showers, pressure relief and safety valves
- Accurately measure emissions and environmental compliance
- People tracking, wireless video
Productivity Enhancement and Plant Management: The list goes on... on page 5!
Productivity Enhancement Applications:
- ● Remotely access process control and asset-management systems
- ● Broadcast messages to specific groups using VoIP, VoWLAN, SMS, conference calls, voice mails etc.
- ● Access maintenance work orders and instructions through handheld communicators
- ● Track or report inspections, tests and repairs
Plant Management Applications:
- ● Plant surveillance to monitor fence lines, entrances, or remote tank farm areas
- ● Safely monitoring for workers in hazardous locations
- ● Monitoring flare, smoke stacks and loading terminals
- ● Monitoring safety areas like mustering stations and safety showers
This is just a broad classification of most widely observed WSN applications. However, it may be noted here that the use of WSN is not limited to the aforesaid list and keeps growing at rapid pace in novel areas and vivid domains. Even in demanding applications such as North Sea offshore oil productions... More on page 6!
Working Case Studies: Wireless Automation for North Sea Oil
Monitoring in inaccessible area: StatoilHydro is the leading oil and gas operator on the Norwegian continental shelf. The Grane platform is operated by StatoilHydro, and is stationed in the Norwegian Sea off the coast of Bergen, Norway.
Problem: To remotely monitor wellhead and heat exchanger in harsh, difficult to reach areas crowded with metal pipe work, walkways and other obstructions.
Solution: Emerson Process Management has successfully applied its wireless selforganising mesh field network to monitor wellhead annular pressure and heat exchanger pressures on the Grane offshore platform.
How Non–Intrusive WSNs Helps To Quickly React to any Loss of Well Pressure
Problem: To early detect the flow loss to enable operators to flow the well through the test separator and thus re-establish flow by reducing pressure. Bringing flow back quickly improves throughput and significantly increases production.
A non-intrusive flow metering solution required that could be implemented without shutdown and production loss in heavily crowded area (to be mandatorily kept clear for safety reasons) without cabling, cable trays and junction boxes.
Solution: Emerson‘s wireless temperature transmitters were installed to indirectly indicate flow on lines at each of forty wells. In contrast with the once-a-shift manual recordings, the wireless devices now transmit readings every 30 seconds back to the wireless gateway. Gateway is hardwired directly into the existing control system providing operators with the real time information; they need to react quickly to any change in flow.
Discover, why the trend is shifting away from legacy–based wired technologies on page 7!
The Trend is Shifting From Legacy–Based Wired Technologies to Wireless Technologies
Wireless Sensor Network (WSN) based solutions were not been considered as viable and preferred choice for automation in Oil and Gas (O&G) sector, due to reasons such as – being in development stage, nonrobust and immature technology, security concerns, incomplete or conflicting standards and clashing wireless frequencies and communications protocols etc.
Today, we observe a total transformation is happening in terms of the industrial shopfloor perspective. Advances in safety, security, affordability and maintainability within the constraints of frequency allocations, now enable organisations to take full advantage of wireless technology for hazardous, inaccessible and thereby challenging industrial environments.
Yet, optimising every facet of the solution is vital and imperative. There are some issues and challenges that could be identified as areas of future research work.
Learn more about wireless automation technology at this year's Hannover Fair in Process Automation and Industrial Automation – A Big Window on Process Industry
References:  Jignesh G. Bhatt and H.K. Verma. “Wireless Sensor Networks for Industrial Process Control and Automation: A Review”, presented at the AICTE/MHRD sponsored Winter School on Instrumentation & Signal Processing, Dr. B.R. Ambedkar National Institute of Technology Jalandhar (NIT Jalandhar), Punjab, India, January 2010. Invited Expert Lecture. Jignesh G. Bhatt, “Wireless Networking Technologies for Automation in Oil and Gas Sector”, in Proc. International Conference on Management of Petroleum Sector (ICOMPS-2010), Pandit Deendayal Petroleum University, Gandhinagar, India, March 3-5, 2010, Section-III: Techno-managerial Issues in Oil and Gas Sector, Paper No. 10, pp. 51-71 (ISBN: 978-93-80043-90-6).  Jignesh G. Bhatt, “Development of Wireless Sensor Networks for Process Industry” M. Tech. Thesis, Department of Electrical Engineering, Indian Institute of Technology Roorkee, Roorkee, India, June 2010. Overcome challenges in Wireless Sensor Networks, Jimi Simpson, Jennic, RF Designline Publication (www.rfdesignline.com) (02/21/2007). Industrial Ethernet Book, Demystifying IEEE 802.11 for industrial wireless LANs, Raymond Liao, Christoph Weiler, Wolfgang Bolderel Issue 25 (http://ethernet.industrial-networking.com), March 2005. Industrial Ethernet Book, Exclusive Report with Market Share Projections, imsresearch. com, Issue 54 (http://ethernet.industrial-networking. com), September 2009. Emerson’s Smart Wireless Products – Using Open WirelessHART Standard - Significantly Improve Production at StatOilHydro Gullfaks Offshore Platforms, Smart Wireless Applications, Emerson Process Management, (http://www.EmersonProcess.com/SmartWireless). Emerson’s Smart Wireless Products – Using Open WirelessHART Standard - Significantly Improve Production at StatOilHydro Gullfaks Offshore Platforms, Smart Wireless Applications, Emerson Process Management, (http://www.EmersonProcess.com). Industrial Ethernet Book, Managing Wireless Networks for Secure Enterprise Control, Stan DeVries, Hesh Kagan, Invensys & Ian McPherson, Apprion, January 2006.