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With increasing investment by big players and more momentum in wireless standards, the business case for wire-free industrial solutions is becoming clearer, says Madanmohan Rao.
“Manufacturers believe better visibility has huge potential value in the form of more consistent use of best practices, higher plant utilisation and improvedoperational safety”, says Harry Forbes of ARC.
With its dramatically lower installation cost, which ARC believes will cause the normal change-averse process industries to use it wherever they can, leading to more rapid adoption, wireless process sensing isexpected to be the fastest growing market segment.
As for wireless LANs, their adoption will be accelerated by new access point products that can safely be installed in the hazardous environments that may be present in such plants. The longer range and clearer signals provided for in future wireless standards should also make LANs more attractive toprocess manufacturers.
The market potential of industrial wireless has also attracted attention from major players to invest in promising startups that can be integrated into theirlarger suite of offerings.
For instance, Motorola Ventures, the strategic venture capital arm of wireless giant Motorola , recently announced an investment in Apprion, a supplier of open industrial wireless networks and applications. With the Motorola Ventures investment,Apprion has now raised over US$23.5 million.
Apprion’s ION System enables industrial facilities to deploy and manage multiple wireless applications as one unified, integrated system. This includes an onsite multi-RF controller that manages data services, workflow, security, monitoring and maintenance, and third-party application integration across wirelessplant networks.
“Over the last decade wireless technologies have radically changed how we live. Over the next decade, we expect to see wireless technologies transform manufacturing by the same magnitude,” says John O’Donohue, Managing Director, Motorola Ventures.
Developing standards
Much of the standardisation activity has been in WirelessHart and ISA100. ISA100 has a broader scope in terms of safety, control, monitoring and mobility features. The WirelessHart standard was specified in September 2007 and is now going for IEC adoption, while the compliance programmes for ISA100 are expected to kick off in late 2008 or early 2009.
The ISA100 standards committee on wireless systems for industrial automation met this past June in France to advance the development of a universalfamily of wireless standards.
The recently approved Wireless Convergence Subcommittee, ISA100.12, held formative meetings to define membership guidelines, review and revise subcommittee scope, assign tasks to subcommitteetask groups, and discuss preliminary deliverables.
This subcommittee will initially address convergence of the ISA100.11a standard and the WirelessHart specification. Initial deliverables will include organization of the recently released WirelessHart portion of the HART 7.1 specification into a format suitable for convergence discussionswith ISA100.11a, as well as a providing a framework for evaluating convergenceoptions.
Meanwhile, the ISA100.21 working group on people and asset tracking and identification reviewed their latest draft of “A Review of Technologies for Industrial Asset Tracking”. This document describes real-time location service or system (RTLS) technologies that are being touted by vendors as optimal forindustrial asset monitoring.
There is increasing agreement on the common vocabulary to describe the terminology associated with wireless technology and its implementation in industrial automation.
“Wireless is changing the way our customers think about manufacturing,” stated Jack Bolick, President, Honeywell Process Solutions, recently. “Process manufacturers have been asking for wireless networks that can handle thousands of wireless devices in a plant: transmitters, meters, sensors, hand-held devices and countless others. “Needing to have a separate wireless network for each kindof device is an expensive and cumbersome proposition.”
In June, Honeywell announced an updated version of its OneWireless industrial wireless network equipment that is designed to be compatible with the ISA100.11a industrial wirelesscommunication standard.
“The latest OneWireless release is the process industries’ first mesh network with ISA100-ready hardware. The network can be easily upgraded to the ISA100.11a standard, when it is completed,through an over-the-air software update,” read the announcement.
“Manufacturers have been asking for a secure and reliable multifunctional wireless network that can handle the thousands of devices they use within their plants,” said Harsh Chitale, vice president of strategy and global marketing for Honeywell Process Solutions. “Until now, the only way to do so was with proprietary systems. The ISA100.11a standard will allow OneWireless users to achieve thisvision using a standards-based network.”
“Our sights are broadening to investigate how to accommodate existing protocols that may not be especially developed for industrial environments but may find use there,” says Wayne Manges, ISA100 co-chair. One such example is the creation of a new interest group that will begin preliminary evaluation of the applicability of ZigBeewithin the ISA100 family of standards.
As for other related standards, the Internet Engineering Task Force’s Routing over Low-power and Lossy Networks (ROLL) group is also pursuing a standard for control and sensor nodes onBluetooth, Wi-Fi and 802.15.4 nets to link to the broader Internet.
This is also expected to help define the next phase of embedded Internet and reduce the challenges of multiple translation gateways on integrated scaleablenetworks.
The green link
With gover nment legislation on the horizon requiring coal-fired generators to pay fees to emit global warming gases, the shift toward energy efficiency becomes more compellingand cost-effective.
Against this backdrop, ZigBee Smart Energy is aimed at providing an affordable and easy way to improve energy efficiency and reduce environmental impact, according to Bob Heile, Chairman of the ZigBee Alliance, a global ecosystem of companies creating wireless solutions for use in energy management, commercial and consumerapplications.
The ZigBee Smart Energy public application profile is a readyto- use solution offering utilities and technology suppliers a secure, interoperable, wireless global standard for developing products that improve energy management and efficiency for both consumers and corporations, who will then be in a better position to respondto government demands for energy efficiency.
In May 2008, the Alliance certified 19 ZigBee Smart Energy products. These products represent a full range of devices necessary to implement a wide variety of advanced metering infrastructure (AMI) programs.
Sensing opportunities
Sensors for temperature and relative humidity are moving into wireless modes and configurations. For instance, Banner Engineering’s SureCross sensor is now optimised for use with thecompany’s SureCross Wireless Network.
The SureCross Temperature and Humidity Sensor is factorycalibrated to determine relative humidity to ±2% or ±3.5% (depending on model) and delivers temperature accuracy to ±0.3° C for simple critical data monitoring. It can now operate as a wirelessnode to operate on a FlexPower battery supply for up to 20 years.
Fixed and remote-mount node and sensor models enable a wide range of installation scenarios, including in-duct and freestanding applications. The wireless option provides a robust, reliable wirelesssolution with bidirectional fully acknowledged data transmission.
“Monitoring the optimal temperature and humidity in controlled storage areas is crucial to ensuring optimum product quality,” according to Chris Dales, Senior Application Engineer, Banner Wireless Division, which also manufactures a range of wireless networks, photoelectric and ultrasonic sensors, vision sensors, electronic machine guarding systems, fiber optic assemblies and precisionmeasurement systems.
And startup companies are noticeably active in this industrial space. For instance, GainSpan is working on Wi-Fi sensor nets, and has reportedly developed a Wi-Fi chip that can be directly attached to batteries drawing as little as 1 to 5 microamps in standby mode. And Dust Networks’ implementations are being used in coalplants to monitor whether motors are running or on the verge of breakdown.
Eltav Wireless Monitoring is developing wireless monitoring solutions for industrial ball valves. The sensors verify the proper functioning of the valves, via wireless signals to central control rooms; the sensors’ batteries last five years, greatly reducing electricity consumption and its related costs. Eltav CEO Israel Radomsky is a member of the ISAstandards committee.
Oil & gas demands
Wireless is a key investment area across the whole oil and gas supply chain including refineries/ petrochemical plants, pipelines, exploration & production, andtransportation.
While profits are high, the cost of doing business is increasing as oil and gas supplies become more difficult to find and exploit. In addition, refineries and petrochemical plants face stringent regulations and areoperating at near full capacity.
Several new entrants, startups, and industry consortiums have emerged to develop wireless sensor innovations for internal pipeline corrosion monitoring, wellhole drilling andcompletion, seismic sensors, and nanotechnologies.
Alerting and monitoring applications are overwhelming candidates for wireless systems in early stages of design and deployment, says Koji Demachi, Head of Technology Marketing for Yokogawa Electric Corporation. These findings are based on the ISA 100 Usage Class definitions for wireless communications, which include safety,control, alerting and logging.
Demachi cites typical wireless applications in the oil and gas sectors, such as monitoring of wellhead, pipeline, chimney top, tankyard and rig. Wireless implementation projects should ensure mission criticality (via reliability and robustness), openness (via interoperability), wide area scope (via scalability and flexibility) and regulatoryrequirements (via compliance).
This is the typical challenge with global standardisation, Yokogawa’s Demachi explains, balancing short-term growth with long-term stabilisation and future-proofing. Still, he urges that field trials proceed so that experiences could be accumulated and confidencefactors increased.
Madanmohan Rao is editor of “Asia Unplugged: The Wireless & Mobile Media Boom in Asia-Pacific”.
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Wireless Widens the View
A wider window into the plant is now possible as previously difficult-toaccess field data becomes easier to collect and transmit with the latestwireless technology. By Jonas Berge.
Information that was previously difficult or impossible to access in the past is now easily collected and transmitted from wireless devices to the plant control system. As a result, incremental asset health and process status data is delivered quickly and continuously to the right individuals, producing:
• Improvements in asset maintenance
• Greater equipment reliability
• Reductions in plant downtime
• Improved process control
• Better safety
• More certain compliance with environmental regulations
• Lower installation cost than most hard-wired systems can deliver
The most advanced of these wireless systems coexist with, and complement, other wirelessnetworks operating in the typical plant environment.For example, existing IEEE 802.11 Wi-Fi broadband wireless Ethernet and TCP/IP standards are already built into thousands of products used in and aroundindustrial plants.
Using industrial-grade Wi-Fi infrastructure, new solutions can be found, and new work practices can be adopted. Workers in the field easily access desktop applications and perform tasks from a tablet PC – including viewing and responding to alarms, observing the process, and retrieving work orders. The personal communications methods enable workers to be more productive in checking onequipment while away from the control room.
Challenge of change
Control requirements and circumstances change over time, which calls for existing control systems to change and/or assimilate much more information than may have been required originally.
For instance, new or more stringent regulations for Health, Safety, and the Environment (HSE) are now enforced in many countries. This may require continuous monitoring of safety showers around the plant so that help can be dispatched if needed. Likewise, there may be a need to know the status of manually operated valves to be sure they are in the correct position to avoid accidents due to false assumptions. And safety relief valves may need to bemonitored to detect venting.
Manpower reductions or the need for more frequent updates may make it impossible to rely on operators walking the plant floor with a clipboard to take visual readings. Or it may be desirable to reduce manual measurements in the field where there is possibility of error or risk ofpersonal injury.
To reduce downtime, it may also be wise to continuously monitor assets like pumps and motors for leading indicators of wearand-tear versus periodic manual checks.
All of these things can be accomplished with field instrumentation reporting to the control room. However, installing wired transmitters to perform new functions is usually phenomenally expensive. In many cases, plants have run out of spare signal wire pairs, spare tray space, spare DCS I/Opoints, and adding them is not easy. Even in new plants, there are manyremote locations that cannotbe reached economically withwire or cable.
Interestingly, in many applications, it is about replacing non-wired devices with wireless. For example, pressure and temperature gauges, variable area flow meters, and level sight glasses that are not wired to any system and must be read manually no matter where they are installed cannow be connected wirelessly.
Wireless plant systems are already delivering impressive business results, including new solutions to problems and fast deployment. Table 1 (overleaf) summarizes some of the latest,innovative wireless solutions being deployed by users.
Hart makes a start
While wireless transmitters are relatively new, a standard covering their manufacture and use is already in effect. WirelessHart is an all-digital wireless protocol that was approved as a controls industry standard in 2007. This assures that companies wanting to incorporate wireless technology won’t have to rely on a limited number of products provided by a single manufacturer. Devices from several suppliers can work together easily because they are built to this standard.
WirelessHart transmitters utilize the IEEE 802.15.4 standard ensuring it can coexist and share the same airspace as Wi-Fi. The same IEC 61158 application layer as for wired Hart devices is used on top of this, ensuring easy integration with existing device managementsoftware.
It is worth noting here that IEEE 802.15.4 is often used synonymously with ZigBee but this is incorrect. ZigBee is just one of several network and application layer protocols using IEEE 802.15.4 physical layer and data link layer protocols. WirelessHart uses IEEE 802.15.4 but is different from ZigBee. Bluetooth is IEEE 802.15.1 and is not used by wireless field networks because it requires more power than ZigBee, operates over short distances andhas no mesh topology.
Devices adhering to WirelessHart standard are capable of supporting any kind of sensor, so they will work with nearly any industrial application, whether for control or monitoring, just like all Hart products do today. A number of leading manufacturers have announcedthey will supply transmitters and gateways meeting the WirelessHart standard.
Infrastructure decisions
Whether wireless is deployed in a new plant or an old one being updated, the wireless infrastructure can remain in place for many years, so making a decision about wireless is very important, much like deciding on a control system. Reliability and security are the main considerations for an industrial wireless network, and both are addressed by WirelessHart.
A unique characteristic of WirelessHart is the self-organizing mesh-based network that provides transmission reliability by dynamically routing messages around signal obstructions as they occur. It is capable of “working around” communications problems that frequently occur in a plant, so it cannot be impacted by them. The protocol always includes “status and value” data in addition to any kind of configuration data. This gives users insight into thevalidity of their measurements with the assurance that values are correct as reported.The self-organizing ability of wireless mesh networks pays off when obstacles such as sky lifts and scaffolding appear, or even when trucks temporarily block the established signal path. The network simply finds an alternate path for the signals to reach the gateway.Mesh networks are therefore more robus.
Table 1: Recently deployed wireless solutions
The mesh protocol also reduces the number of gateways (transmission receivers) required because every device acts as a transceiver, capable of relaying messages from other devices which are not in the line-of-sight of the gateway. This makes wireless field networks easy to deploy, since the site surveys commonly requiredfor line-of-sight communications systems are eliminated.
Measures used to combat channel noise include channel hopping, black listing noisy channels, and using “spread spectrum” transmission. Security measures include encryption, connection authentication, and message verification.
Most plants use a mix of protocols such as wired Hart for safety devices, Foundation fieldbus for control instrumentation, and Profibus-DP for motor starters and drives. These integrate into control and device management systems, enabling all devices to deliver accurate, actionable information to the right person in time to make a difference. Since wireless instrumentation is new, different requirements apply to the wireless field network, and these must bedefined when engineering a new system or upgrade.
Legacy potential
At first glance, that distributed control system (DCS) in the plant may appear too old to support wireless. But this apparent stumbling block can b overcome through the use of “wireless gateways” – field devices that can be integrated with the existing system, whether new or old. In fact, a WirelessHart gateway can be added to a control system not supporting WirelessHart.
Because the wireless gateway supports Modbus/RTU, Modbus/ TCP, and optionally OPC, it can be connected to legacy control systems while providing process variables from wireless transmitters despite the lack of native wireless support. In addition, an HTTP Web server embedded in a wireless gateway enables setup of the WirelessHart network from a regular Web browser without support from the control system.
Intelligent device management software can be deployed alongside the legacy control system with all device-related information efficiently passing between the field instruments and the device management software. Thus, older plants can enjoy the benefits ofwireless and device management.
Consider also the aging of the wireless infrastructure, which can have a lifetime of 15 years, much like a control system. How can device management software purchased today configure and diagnose different types and new versions of wireless devices that come into the plant in the future?
This compatibility is ensured through the use of the IEC 61804-3 standard Electronic Device Description Language (EDDL), just as for wired Hart, Foundation fieldbus, and Profibus devices (see Control Engineering Asia, September 2007).
Each time a new wireless transmitter or version comes into the plant, the software is kept current by copying the device’s EDDL file onto the system. The file enables the device management software to render the user (HMI) display exactly as intended by the device manufacturer, and provides access to know-how in the form of helptext and context-sensitive images.
First steps andbeyond
The first wireless point is inevitably the most expensive, because to deploy one transmitter it is also necessary to install the gateway, computer, and software, etc. However, once this infrastructure is in place, installing each subsequent transmitter will cost very little more than the device itself, because one gateway supports many transmitters.
As soon as that first wireless network begins to function, operations and maintenance people will find numerous other applications around the plant, fulfilling long-held desires for asset monitoring and process data collection. Look for applications in your plant by listing the measurements that are currently collected manually – or not at all. Monitoring applications offer a good opportunity to evaluate the technology with little or no risk.
Obtain a wireless starter kit through your maintenance budget. Use the kit to try out wireless and involve all departments – engineering, operations, maintenance, etc, to give everyone a chance to see how this rapidly emerging technology can enhance equipment reliability, reduce plant downtime, improve process control, and result in a safer workplace.
Jonas Berge is Senior Manager, PlantWeb Consulting, at Emerson Process Management Asia Pacific.
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What About the Users?
Wireless vendors need to educate users more, and to sell benefits, not just hardware and software – just one of the findings from a recent industry study. By Jim Taylor.
Satisfaction with the wireless technologies implemented for industrial monitoring and control is on the increase, according to a Venture Development Corporation (VDC) study on this topic. Specifically, fifty-nine percent of users rated their satisfaction as “very high” or “high”, compared to 45 percent in 2005.
For the purpose of the study, VDC included the following wireless (RF or microwave) product categories:
• Data acquisition systems
• Network products
• Operator interface terminals
• Remote controls
• Sensors
The interview and Web-based survey targeted purchasers and specifiers of these products, and included end users, original equipment manufacturers, and system integrators.
As for the reasons for introducing wireless technology, lowering cost, adding flexibility, and easing of implementation came out on top. Other factors were customer demand, mobility, reach (only way to get there), protection against wire damage, and increased safety.
The main areas contributing to cost savings were cited as: lower installation costs (labor and materials); lower maintenance costs; greater flexibility for additions and changes; higher reliability in specific applications; more efficient use and reduction of personnel needs through the use of wireless mobile operator interface terminals.
Still hesitating
Those not using or planning to implement wireless technology in monitoring and control applications were asked what could induce them to do so. The three most frequently identified reasons were:
2. High security protection
3. Reliability equivalent to (or better than) hard wiring
Less identified were better education on technology and products; customer requests; evidence of resulting productivity improvement; and only use for new installations, not for retrofitting of existing applications.
These points could serve as guidelines for how vendors could convert these people into customers. Vendors need to educate users more, and to sell benefits, not just hardware and software. VDC found much more concern about security compared to 2005 when 31 percent indicated they had no security concerns, versus only three percent saying they have no security concerns now.
Encryption of signal transmissions is by far the most suggested means for providing data security. Others include password codes, limiting the power of signal transmission to allow only short-range reception, and using directional antennas.
As with security, concerns about interference increased in this study, suggesting that these challenges tend to coincide with greater wireless systems experience. Leading interference concerns are: signal blockage and multipath needs due to metal structures, and interference from equipment-generated noise.
Jim Taylor is Director for Industrial Automation, Venture Development Corporation (www.vdc-corp.com).
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Smart for Steel
Installed in a hot strip mill, this self-organizing wireless network is providing previously unattainable data for operations and maintenance personnel and spurring quality andproductivity improvements.
The Wheeling-Pittsburgh Steel Corporation is a major producer of carbon flat-rolled products for the construction, container, appliance, converter/processor, steel service center, and automotive markets. The Smart Wireless network from Emerson Process Management is now installed and working in the roughing and finishing sections of the 80-inch hot strip mill in Mingo Junction, Ohio.
The first project involved the use of four Rosemount wireless dP flowmeters with Annubars and one 1420 gateway. The resulting data enabled operators to get firm control of the volume of water being sprayed onto the hot steel surfaces on the run-out-table in order to achieve specified coiling temperatures. Operators soon learned that actual flow rates of spray water to the run-out-table were far different than assumed.
“We previously had no way of knowing how much water was being sprayed over the surface of any given piece of steel traveling down the run-out table. The volume of water applied was determined by look and feel with the adjustment of a manual valve,” notes Gary Borham, Operations Manager.
“Now, the actual water flow is known, making it possible to always attain the optimum coiling temperature. The guesswork has been taken out of the cooling process and replaced with science.”
In another application, wireless pressure transmitters are used, to monitor the pressure of cooling water supplied to work rolls in the roughing mill. If the water pressure should drop suddenly, an alarm is raised so action can be taken to prevent roll overheating. One of these devices is located on the floor of the maintenance shop two buildings away from the control room, communicating through concrete walls.
Realizing opportunities
According to Borham, “We are building an infrastructure that opens up opportunities for more and more applications. Wireless transmitters are being installed farther and farther away from the gateway without a loss of signal quality.
“The result is better information from difficult-to-reach areas of the mill, and this is helping our personnel prevent unscheduled downtime, meet customers’ quality requirements, and optimize productivity.”
Installing conduit and wiring for any of these applications would have been very time-consuming, Borham says. Clearly, an easy-to-install technology was needed that could handle the steel mill environment while providing information critical to improving operations.
The self-organizing network automatically adapts as device points are added or removed, so installing more transmitters has become common since the initial installation. The transmitted signals are received through a single gateway and delivered directly to the Pi data historian for trending and alarming. The operators therefore have continuous access to the data which they are using to improve operations and maintenance.
According to Gary Borham, “This is a fantastic solution for us, easy to install, and very easy to expand, if necessary. In fact, our process engineers are using data provided by the wireless flowmeters in modeling future control schemes for heavier gauge products. Having that information available in advance and being able to control the water spray accordingly will enable us to quickly meet specifications without rejects.”
Source: Emerson Process Management
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