Wireless

From my RSS feed, an Automation World article, Wireless Eliminates Ground Loop Noise, caught my attention. It brought back memories of being a systems engineer on offshore oil and gas production platforms. These platforms are huge steel structures and as such, have a nice solid ground.

These structures also act as antennas for electromagnetic interference (EMI) from the starting and stopping of large motors and generators. I became very familiar with the filtering features on the inputs to the automation systems we had at the time.

Unfortunately, I didn't then know ModelingAndControl.com's Greg McMillan who pointed out some downsides with signal filtering:

...signal filtering can be used to smooth out the noise but this adds a lag that reduces the ability of the flow loop to deal with pressure disturbances and valve issues.

The article identifies what will warm the hearts of Electrical Engineers but may be overlooked by other engineers:

What's more, the tests turned up an added bonus. "Because the wireless transmitters are battery powered, this totally isolates them from spurious ground-loop potentials that get introduced into any reaction vessel from a number of different sources, and which drive pH sensors crazy," Broadley observes. During the test, when a ground-noise-induced spike appeared on the wired pH signal, it was not present in the wireless transmitter output.

I know how much time I spent chasing spurious, phantom issues caused by EMI or ground loops on onshore facilities. I imagine a few of the plant engineers who come upon this post, may have similar stories to tell. For some plants, this may turn out a bigger advantage than the wiring savings or trapped diagnostic information in HART field devices.

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I don't want to admit how long I've know Emerson's Kurtis Jensen, but it does goes back to the pre-Emerson days at Fisher Controls. Kurtis is an instrument product manager for the Fisher Valve and Valve Automation businesses. He's penned a great article for Valve magazine, A Bright Future for Wireless Technology. He encapsulates his thoughts:

Industry has a watchdog that can save costs, provide reliability and allow more confidence that our valves are in good health and operating at peak capacity. The technology can also work toward a safer work environment and provide more information for improving processes.

The watchdog of course is wireless. Just as how it has become indispensible in our homes and given us the freedom to connect from anywhere, Kurtis describes its benefits to process manufacturers. It eliminates:

...the time and effort it takes for manual audits; the amount of occasions in which someone is sent into undesirable conditions; and product variances, which when reduced can improve product quality.

In most processes, manual valves can be found in many places. One example is their use in maintenance cleanout activities. Adding wireless valve position feedback can:

...improve process reliability: it protects product quality, it protects against scrap or rework, and it protects against clean-up actions. The end result is a more reliable process and greater confidence that all is well.

Without this valve position feedback, more operational resources are required to follow standard operating procedures to verify that the valves are in their correct open or closed position.

Kurtis reminds the reader why manual valves are automated:

First, moving the valve may require too much manual effort. Second, it may be desirable to eliminate having personnel in dangerous conditions such as precarious heights or hazardous environments. Third, it might be necessary to reduce complexity and time needed to coordinate valve adjustments during plant operations.

For the on-off variety of automated valves, many today are driven from the automation system by a solenoid. The command is issued but there is no feedback from the valve that it went from open to close or close to open. Traditionally, this feedback required two sets of wiring on the valve positioner side and two discrete input (DIN) channels on the automation system side. This may not be a big issue if spare pairs of wire are available and spare DIN channels are available. Usually though, if it's not a big issue and knowing its state is important, the valve position feedback is already present. Kurtis notes:

Knowing more about a valves' health enables better decisions and faster maintenance. It is just as simple and easy to achieve significant improvements on these old valves as with new projects. Facilities that implement wireless feedback have the competitive advantages of operating cost reductions, improved product quality, increased production volumes and increased levels of safety.

Beyond more feasible valve monitoring, Kurtis closes with a thought from the automation system control strategy perspective:

Designers of control strategies will take advantage of wireless valves to enable greater control as well as greater process and equipment health awareness, all of which results in greater confidence in operations and processes.

Kurtis summed up his thoughts on wireless even beyond valves to me in an email, "If it moves you can monitor it!" If you have manual valves or others without position feedback that has caused operational or safety-related issues, this might be an article worth your time to read.

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Update and bump: Greg's article is now live on the ISA.org InTech website. Below is the original Dec. 15, 2009 post.

I received an advanced copy of an article ModelingAndControl.com's Greg McMillan has recently completed, Exceptional Opportunities for Smart Wireless pH and Conductivity Measurements. In the article, he summarizes these opportunities:

...for inferential measurements, solution temperature correction, efficient calibration, noise minimization, and predictive maintenance by taking the advantage of smart features and wireless communication.

On inferential measurement, Greg notes that the connectivity, intelligence and portability of wireless conductivity and pH measurements increase the possibilities for successful inferential measurement creation. He writes:

The availability of the primary process variable (pH), and the auxiliary variables (milliVolts, temperature, reference impedance, glass impedance, and RTD resistance)... for a smart wireless pH transmitter, facilitates the monitoring of sensor performance besides developing relationships for solution temperature compensation, solvent concentration, and CO₂ loading.

Inferential models developed within the automation system neural network algorithms use conductivity, pH, and temperature inputs to better predict solvent concentration and CO₂ loading.

With respect to temperature compensation, Greg observes that the standard temperature compensation in pH measurement as defined by Nernst equation does not account for actual solution pH changes with changing temperature. Additional solution temperature compensation in smart pH transmitters is beneficial for many applications. Greg shares:

Lab tests where the pH and temperature of the sample are varied to cover the operating range are required to quantify the effect of weak acid and base dissociation constants on solution pH. Smart wireless pH transmitters allow the user to develop, document, and integrate the solution temperature compensation results from lab tests.

Most automation engineers have faced issues with electromagnetic interference (EMI) causing noise on their process measurements. For pH measurements, spikes can be caused by ground loops or the operation of motors and variable speed drives. Wiring to the instrumentation can act as an antenna for this noise. Wireless devices avoid the EMI issues that wiring induces.

Many pH applications are difficult, due to electrode coating, plugging, and aging that can occur in days or weeks. Wireless lab and field pH and conductivity measurements in a lab process sample:

...creates interesting opportunities for predictive maintenance on when to clean or replace electrodes.

The technology team envisions how these smart pH and conductivity measurements could be enhanced with:

...a model for a particular sensor and run a simplified principal component analysis (PCA) within the transmitter to detect a failure.

The article shares specific examples of the team's work with the University of Texas and their absorber for CO₂ capture and distillation column for solvent recovery. I'll update this post when I know when and where the article will be published. Until then, I hope this gives a brief sample of some of the innovations occurring on the pH and conductivity measurement and control fronts.

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ModelingAndControl.com's and Emerson technologist, Greg McMillan, will be presenting tomorrow at the ISA's Boston section. His presentation, Exceptional Process Control Opportunities describes how advances in measurements, valves, and control can make a dramatic difference in important applications such as bioreactor, compressor, exothermic reactor, and neutralizer control. For those that can join this event, Greg has promised:

...giving out 10 free copies of my book The Funnier Side of Retirement for Engineers and People of the Technical Persuasion to balance out the serious stuff.

I asked Greg if I could upload his presentation to SlideShare.net, so that I could embed it here and share it with all of you. He graciously agreed. I'm also hoping social media maven, domesticatingIT blogger, and ISA Boston section president, Jon DiPietro, might have Greg's words recorded so we can turn the presentation into a slidecast.

Some of the wide-ranging ground Greg covers in this presentation includes wireless measurement and control, sample time concepts, integrating processes such as batch processes, controller tuning, precision control valves for pH control, expertise retention and development, and open loop backup such as compressor surge and U.S. Resource Conservation and Recovery Act (RCRA) pH.

Greg also promises future blog posts for a whole lot of items he's not able to cover including batch profile controls, adaptive feedback control and linearization, adaptive FeedForward control and linearization, full throttle set point response for batch and startup, controller output overdrive, dynamic reset limit, fast and intermittent disturbances and discontinuities, integration of loop, process, and maintenance data, root cause analysis, data visualization, virtual tool for learning and exploring opportunities, peak control. If you have interest in any of these topics you'll want to subscribe to the blog's RSS feed, if you're not already subscribed.

Greg, being a prolific author extraordinaire, also points to a soon-to-be released work, Essentials of Modern Measurements and Final Elements in the Process Industry. He is donating the royalties from this book to the University of Texas Research Campus for Energy and Environmental Resources for development of wireless instrumentation and control.

If you're in the New England-area tomorrow, here's the event page to find out more details. If you're not, look at the embedded presentation and see some of the wisdom Greg shares, particularly in the slide 22: Wireless PID Control Conclusions, slide 24: Sample Time Guideline Notes, slide 33: Integrating and Runaway Process Tuning, and slide 45: Best Practices to Improve Valve Performance.

Update and bump: I sat down with Greg on Friday and recorded an audio track of his presentation and synched it with the presentation to create a Slidecast.

Check out Greg's findings beginning at slide 14 on how the the behavior of wireless PID control had less oscillations to wired PID control. It was somewhat of a surprising finding.

At last week's Emerson Exchange, John Rezabek of ISP presented Wireless or Fieldbus? You might recall John from his columns in Control magazine and on the ControlGlobal.com site. He presented a cost comparison for a plant expansion considering Foundation fieldbus instruments versus WirelessHART-based ones.

John values the digital integration of field devices, which both technologies provide. I asked if he minded if I blogged his presentation and he was OK with it, as long as I wasn't disruptive (only kidding on the disruptive part!)

John did an analysis on a project to purify a co-product using two distillation columns and adding intermediate and project storage as needed. The process required the measurement and control of flows, pressures, levels, and temperatures around the column. The project included 16 control valves, 14 control loops, and 16 indicate-only measurements.

Conduits, wires, and stainless steel junction boxes are expensive and complex. Wireless has the great promise to save design and installation costs associated with wired systems. Wireless does not replace all wires because of the power consumption requirements on some of the devices like control valves' digital valve controllers. Also, some of the indicate-only devices, such as RTD temperature sensors, required wires and associated cable raceways. This lowers the incremental savings since the tray and junction boxes would still need to be present. John's analysis also considered conduit and basket tray for the wires in both the wireless and Foundation fieldbus cases.

The project would already run a network of RGS conduit and twisted pair fieldbus cable for the control valves. The analysis compared the incremental costs for the wireless instrumentation-related services against Foundation fieldbus device-related services. Also, a home run wiring infrastructure for both cases was considered pre-existing. Other assumptions used for the analysis were list prices for the instruments and local, union, man-hour labor rates.

John calculated the Foundation fieldbus wired case to be just over $25,000 (USD) and the wireless case to be just over $27,000. The main difference is the difference in list prices of the devices and differences in the conduit and terminations required. In his summary, John noted that the actual price of the devices based on the buying agreement might have an impact on the analyses others might conduct.

From an engineering standpoint, John attributes more spec sheets, more devices, device cost, fewer drawing, lower change impact, less power conditioners, and similar configuration to the wireless case versus the Foundation fieldbus case.

From a design effort standpoint, no junction box drawings, fewer terminations, no termination hardware, no field power because of the batteries, less conduit, and less total copper used for the wireless case.

Points John made favoring a wired approach included: uncertainty about column temperature control, uncertainty about update frequency adequacy, spares diversity, signal integrity, and wireless protocol diversity with ISA100. His points favoring the wireless approach included easier infrastructure for future/unforeseen measurements and with things being more-or-less equal--creating a foothold for future opportunities.

He closed noting that 2-wire multi-drop bussed I/O squeezed the wireless installation advantage and the use of basket tray versus conduit tightens this advantage even more. As long as a wired backbone is needed for control services, wired strategies for indicate-only devices are cost comparable. The case for wireless was not a slam-dunk for this project, but (not unlike fieldbus) we all have to do the math for our individual circumstances.

As I noted in an earlier post with wireless devices used in control applications, technology advancements in control, communications, and power over time might alter the necessity of the wired backbone.

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We're now inside of a week from the Emerson Exchange conference in Orlando. One of the sessions I definitely plan on visiting is one by Dr. Frank Seibert of the University of Texas at Austin and Emerson technologists, Terry Blevins and Mark Nixon. Their presentation, Stripper and Absorber Control Using WirelessHART Transmitters will be held Wed, 9/30 at 3:15pm in the Osceola 1 room and repeated Thurs, 10/1 at 11:00am in the Naples 3 room.

Dr. Seibert is the Technical Manager of the Separations Research Program at UT. This cooperative industry/university program performs fundamental research of interest to chemical, biotechnological, petroleum refining, gas processing, pharmaceutical, and food companies. One key area of focus is CO2 removal from stack gas. An absorption system using air/carbon dioxide/amine solvent is used to remove the CO2. The stack gas is sent to the Absorber unit to absorb the CO2 and then a distillation column / stripper is used to strip the CO2 from the amine stream.

WirelessHART pressure and flow transmitters were installed to test control across WirelessHART. WirelessHART pH transmitters were installed to study the CO2 removal from stack gases. WirelessHART multi-element temperature transmitters were installed to monitor the absorber and stripper temperatures. Dr. Seibert wanted the flexibility to work on the absorber and stripper units without connecting and disconnecting cables. This helped reduce downtime and maintenance. The elimination of grounding issues which impacts the reliability and accuracy of the pH and temperature measurement was another advantage of this approach.

Traditional PID control relies on the underlying assumption that the PID controller executes on a periodic basis, mainly due to the calculated reset and rate action. WirelessHART devices conserve energy by reporting on an exception basis--only when the value changes by a set level. Working with Terry, Mark and the Emerson technologists, a patented method was developed in the DeltaV PID control algorithm to support control from WirelessHART transmitters.

The team compared the control performance using the modified PID algorithm and WirelessHART instruments versus a standard DeltaV PID algorithm with wired devices. Column pressure control and heater stream flow control using WirelessHART transmitters and DeltaV modified PID option provide the same dynamic response and comparable performance to that achieved using wired transmitters and traditional PID. An interesting finding was that this comparable performance was achieved when the number of measured samples was reduced by a factor of 10 for the flow control and by a factor of 6 for the pressure control.

More importantly, the cost to relocate wiring has been eliminated through the installation of WirelessHART transmitters for stripper steam flow, column pressure, column temperatures, and pH. With no grounding issues to contend with, the improved accuracy and reliability of the pH and temperature measurements can improve stripper and absorber operation.

This modified PID algorithm for inputs from non-periodic WirelessHART measurement devices is being incorporated into the DeltaV v11 release.

Update and bump: Here are some additional notes live from the presentation. Dr. Seibert noted that 70-80% of their time was in moving and reusing instrumentation. The work is done on skid mounted systems which will be used in actual applications if the research proves successful.

Terry added that simulation was used for the checkout of the flow and pressure loops to verify operation before the loops were commissioned on-site at UT. He noted that tuning of the changed PID algorithm is identical from an instrument tech's perspective.

Emerson's Joel Lemke presented You Can't Manage What You Don't Measure: Getting a Handle on Plant Energy Usage at the 2009 Emerson Exchange. The presentation's abstract is:

User cases will be presented demonstrating how new flow metering installations enabled users to reduce their overall cost of steam, compressed air and other utilities. Until meters are in place, it is impossible to prioritize improvement projects or quantify benefits of existing improvement projects. A metering system should be easy to install and inexpensive to operate to ensure net benefits.

Energy costs remain a large part of operating a plant for many process manufacturers. Joel notes that knowledge is required of the utility fluids of where the energy is flowing and how much is consumed. It needs to be granular to know who is using what at a sub-unit level. Good measurement is required to get the information to make the decisions required to optimize energy usage.

Joel showed a steam system showing three boilers feeding a steam header connected to multiple units throughout the process. This pulp and paper mill began to apply a concerted, energy reduction program when oil exceeded $100 (USD) per barrel. The goal was to compare their usage to industry benchmarks in steam, compressed air, process water, and electricity.

The quality of the installation of differential pressure (DP) flow measurement is key to the accuracy and ongoing reliability of this flow measurement. He shared some best practices. The first is ways to eliminate impulse lines. Consider direct mount installations, which eliminates inaccuracies, provides consistent installations, reduces complexity, reduces leak points, and ends leak testing. Leaks are wastes in energy, put personnel at risks, and increase maintenance costs to troubleshoot and repair.

A new best practice, Joel mentions is to mount the DP meter above the pipe as long as the steam is below 400 degF. There is no imbalance between the upstream and downstream side of the pressure measurements across the orifice.

Another energy saving area is to minimize pressure lost from leaks. By auditing the compressed air systems to eliminate leaks, you can reduce compressor horsepower requirements from the source pressure to the pressure at the destination. Annualize over a year, this can result in large energy savings.

Joel discussed self-organizing wireless networks. The cost per point using wireless was much lower because of the lower installation costs. The mill has added temperature measurement in addition to the DP flow measurement. The WirelessHART measurements enabled much more complete monitoring of plant utilities for the given budget.

In an earlier post, I mentioned a series of European Chemical Industry Wireless on-line webinars. I received a note from the team that the dates and topic focus for the rest of the 2009 webinars have been set. The intent is to show ways chemical manufacturers are using wireless technologies to improve the way they operate their plants. Squeezing out greater efficiencies is critical in these challenging economic times.

The next one, Doing More with Less with Wireless, is slated for September 14 at 3pm GMT (10am U.S. Eastern time). The Emerson European team, consisting of Peter Schellekens, Chris Hamlin, Manu Verschueren, and Ann Robin, identify several areas where wireless enables production, operations, maintenance and project functions to take a fundamentally different approach, which will have an immediate impact on business performance. The team will share examples that have been deployed by chemical manufacturers.

Although registration is not yet open for these future webinars, the rest of the year's schedule is:

Wireless in Projects - A Faster, Cheaper, Manageable Infrastructure - October 19, 3pm GMT

...demonstrate how wireless technologies have the potential to bring alignment between project organizations, with their emphasis on risk, cost and time, and the on-going systems and I/E engineering functions who are more concerned with consistency, sustainability and supportability.

Improving Production Performance with Wireless - November 16, 3pm GMT

...illustrate how wireless can change your approach to performance measurement and monitoring, and bring about significant improvements in productivity, yield and availability. At the same time, applying the same wireless technologies can also positively impact energy efficiency and personnel productivity.

Wireless - More Reliability, Less Maintenance - December 14, 3pm GMT

...illustrate how wireless technologies can reduce the frequency and severity of unplanned equipment failures, enable you to move away from reactive or periodic practices to truly predictive maintenance. Wireless enables you to properly understand the condition of field and process equipment in real-time. This means that you only take equipment out of service if and when it is really necessary, and because problems are identified early and accurately, the duration of any maintenance outage is minimized. Not only does this improve production rates, it also has a very significant impact on maintenance productivity.

Whether you're in the European region or not, or in an industry outside of chemical manufacturing, there just might be an application nugget or two that you can apply in your plant.

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Technologies continue to be introduced, which impact our lives. In the world of process automation, wireless technologies connecting instrumentation to process automation and asset management systems are impacting the way process manufacturers can operate their plants. The Emerson European Chemical industries team will be hosting a series of webinars to show ways chemical manufacturers are using these wireless technologies to improve the way they operate their plants. The first one is coming up in a few weeks on July 6th. I'll update the post with the link to the WebEx registration once it's live.

The global economic conditions have reduced consumer spending and business investment, particularly in the automotive and housing sectors. This slowdown has directly impacted chemical manufacturers' sales and in turn production. During recessionary times, the focus of plants often shifts away from growth toward improving operational efficiency.

At lower production levels, it's important to squeeze out costs to continue to remain profitable. Areas that might have opportunity for improvement include energy efficiency, maintenance savings, water usage, environmental impact reductions, and improved safety. Also, product margins can be preserved by producing differentiated products.

You may recall Peter Cox, a key member of this team from an earlier post. Through him and the team, I got my hands on early builds of information the Chemical Industry specialists will share in the webinars. They see four key areas where wireless instrumentation can help overall efficiency through: improved reliability, increased production, increased visibility to out-of-reach areas, and leaner operations.

A reliability example they cite is any process that has rotating process units, such as reactors or kilns. Wired approaches are tricky and typically have high mechanical failure rates. For one chemical manufacturer, their rotating reactor had to be shut down 2-3 times per week to repair the instruments and/or associated wiring, which no longer was communicating with a PLC. They mounted two wireless pressure/temperature transmitters, one on each end, which communicated with a Wireless Gateway connected via MODBUS to the PLC. This approach ended the measurement reliability problems and improved the efficiency and quality of the product produced in the reactor.

One other example I'll share is in increasing visibility. A chemical manufacturer needed a way to keep up-to-date inventory on storage tanks to support their product sales. Because of the remote location of these tanks from the production plant area, wired measurement was prohibitively expensive. Using wireless differential pressure transmitters, they could send accurate tank level measurements to the inventory management system and allow operators to spot problems with the tank more quickly. It also reduced the need to send the operators into this hazardous area to perform manual tank level readings.

Peter shared with me that the webinars would get increasingly specific and more technical on the applications that chemical manufacturers are solving with wireless plant and field network technologies.

MP3 | iTunes

Update and Bump: The Chemical webinar page with registration is now open.

For many industrial plants and mills, energy costs can be 10 to 20% of their overall business costs. Given these significant costs, leaders in the industrial process industries establish and maintain continuous energy optimization programs to minimize energy cost impact. According to an ARC Report, Best Practices for Energy Management:

Energy can be the largest component of a manufacturer's cost structure. Despite a recent drop in energy prices, costs are still trending upward over the long term...

I caught up with Emerson's Bob Sabin, whom you may recall from earlier posts. Bob is an industrial energy consulting engineer who helps process manufacturers establish this continuous improvement process. It starts and carries on with measuring how much energy is being purchased, produced, and used throughout the plant/mill site. It's important to establish a baseline for steam, electricity, fresh water, air, and process water usage. The perspective should be how much is being consumed by each site area/process. As time goes on, the baseline can be monitored for changes due to equipment issues, energy use can be compared to known industry benchmarks, and projects to improve energy performance can be justified with hard data.

After the survey and measurement phase, it's important to complete basic tasks such as fixing steam devices, maintaining measurement and final control devices, and addressing control loops that contribute to process variability. This variability directly correlates with higher energy consumption. From there, owners are in position to move on to unit process energy optimization and unit coordination for energy savings.

Often key measurements required to monitor energy consumption are not in place because of capital cost barriers. These barriers have been made higher in the past due to the difficulties in running cable infrastructure to the wired instruments. Bob shared how some industrial manufacturers are using WirelessHART measurement devices to significantly reduce the capital cost barriers associated with installation. Bob noted that energy measurement projects today could be completed at one-third the cost as compared to traditional implementations.

He shared an example where one mill added about 70 wireless transmitters measuring steam flows, condensate returns, water and warm water flows, airflows, and air pressures. Given the old adage, "You can't control what you can't measure", these measurements helped identify inefficiencies in the process and give a true energy usage picture to properly assign the costs. Having this energy monitoring information can also help make better profitability decisions by helping to determine product or grade costs during peak and off-peak hours.

Bob described a case where the site's steam use had spiked at a heat exchanger during a condensate flood. This helped the operations team more quickly resolve the situation and save considerable energy waste. Another example is how these wireless measuring devices helped spot air, steam, and water leaks that were not being quickly noticed during maintenance rounds.

I got fired up when Bob closed his thoughts to me with a Vince Lombardi quote, "If you don't keep score [measure], you're only practicing." Game, on!

Update: Podcast added.

MP3 | iTunes

As wireless instrumentation based on the WirelessHART standard continues to move into the mainstream, I get great questions about it by email from time to time. Here's one that came in this week that I thought I'd share:

Do you guys know of a wireless alarm system that we could purchase that would accept an input from a level switch and output a wireless signal to a receiver which is 1500ft away to activate a light/horn. The level switch is in a Class 1, div 2 area. We are just looking a for a stand alone system.

One on the common plant situations that leads automation engineers to think about wireless is distance. Many times, infrastructure like cable tray or conduit paths are not in place. Or as in this case, the annunciator (light/horn) is a great distance from where the measurement takes place and where the automation system is located. In most cases like this one with long distances involved, it's not economically feasible to add the cable infrastructure to solve the problem at hand.

I'm not sure about a standalone solution, but know it could be coupled with a small PLC or to an existing automation system. I checked with Emerson's Wireless Manager, Dan Carlson, about how Emerson might address this application. Dan responded:

The end-user could implement a network of 702 discrete transmitters made by Rosemount that take discrete inputs from any type of switch, including level switches. The signals can then be sent to a Smart Wireless Gateway with either Modbus or OPC outputs routed into a PLC-type device [or natively into an automation system like the DeltaV system] to provide signal response.

Once the wireless gateway is in place and communicating with the automation system or PLC, you can add new wireless measurements or final control elements to the wireless network to provide an answer to wide range of applications.

Wireless-Question-How-To-Connect-Level-Switch-To-Light-Or-Horn.mp3 | iTunes

I saw ARC Advisory Group's Larry O'Brien's post this week, Emerson Profibus Membership is One More Step toward Common Ground. In it, he writes:

In fact, Emerson has supported Profibus for some time. The PNO membership officially seals the deal and gives Emerson a hand in future PNO development activities, most importantly the implementation of EDDL or Electronic Device Description Language in future iterations of Profibus. EDDL is a common technology that is shared across the Profibus, Foundation Fieldbus, and HART protocols, and serves essentially as a markup language that describes the characteristics of devices and how data should be stored and displayed. EDDL files are similar to XML files, and are used to describe equipment parameters, such as device status, diagnostic data, and configuration details. EDDL is operating system independent and host system independent.

Readers of this blog know that we do discuss EDDL and its cross-protocol applicability and importance to process manufacturers--a consistent view into devices from multiple suppliers, multiple digital communications protocols, and multiple operating systems. In one post, I summed it up:

Following the EDDL standard, device suppliers create Electronic Device Description (EDD) files for their smart field devices. These files provide a standardized form and structure for automation systems and handheld communicators to access and display device diagnostic and setup information, independent of communication protocol or operating system.

Emerson's Terry Blevins gave a nice, quick demonstration of this interoperability including WirelessHART devices at last year's ISA Expo.

The EDDL.org team also has quite a number of demonstration videos on their wwwEDDLorg YouTube channel. Emerson's Jonas Berge provides a lot of the energy behind the new content on EDDL.org. He had a conversation last fall with Automation World's Gary Mintchell, recorded in Gary's Feed Forward blog podcast.

As Larry notes, Profibus has been supported around Emerson for a long time. One example is Profibus DP support in the DeltaV system introduced back in the v5.1 release.

Common ground is a good thing when it comes to access to the information in the smart devices which touch your process and have the ability to warn you of abnormal situation which might impact your plant's performance. The advancement of the EDDL standard is one example of this common ground.

MP3 | iTunes

Update: Thanks to the person who spotted and alerted me to the broken link to Larry's post. I've fixed it above and added it here.

Those that come across this blog know that the mission is to give visibility to the expertise of the folks around Emerson Process Management. This post will be slightly different. It does feature an expert, Emerson's Jim Walker. He is a member of the Machinery Health Management business. As part of the Asset Optimization organization, this business is responsible for the CSI Technologies family of machinery health products.

Jim was primary inventor of the CSI 9420 WirelessHART vibration transmitter. This device provides vibration and temperature measurements, diagnostics, and alerts for plant machinery over a self-organizing wireless network for use by operations and maintenance personnel. I know from my days as an offshore oil & gas systems engineer back in the '80s, that adding vibration monitoring after the fact could be a difficult proposition, due to the wiring considerations. I could have used his invention back then!

I did indicate that this would be slightly different. Jim shared with me his spare time interests--film making and still photography. He displays the video portion of these talents perfectly in this video he describes:

...I put together for Emerson's Machinery Health Management business in Knoxville, TN. It follows the progression of construction of the Emerson sponsored Habitat for Humanity house built in April 2009.

Emerson Sponsored Habitat for Humanity House from Jim Walker on Vimeo.

After watching the video (with his suggested, "Turn up your speakers" method), I was inspired by the participation of all the Emerson people in this project and what they accomplished. You'll see them in a montage, starting at 4:25 of this 5:33 production.

Jim, thank you for sharing this with me and I hope it inspires more participation in these kinds of community service activities among Emerson businesses, and with other folks who come upon this post.

MP3 | iTunes

I wanted to give a quick mention of the HART Communications Foundation's annual HART Plant of the Year End Users' Award. They are encouraging nominations from all world areas through May 31. I mention this because some process manufacturers have begun to include WirelessHART into their plants to do some applications that were not possible or practical with a wired approach.

If your organization has been using the diagnostics available in your HART and/or WirelessHART devices to improve your process and/or better manage your assets, you may want to nominate your plant here.

The HART Communications Foundation's Executive Director, Ron Helson stated:

We are seeking the plant that has taken the capabilities of HART instruments beyond configuration and calibration, or one that is using real-time diagnostics and process variables in their HART-enabled devices integrated with their control, information, asset management and safety systems... This is the opportunity for end users to share their success and tell the world how HART technology has helped lower their operating cost and increased plant availability.

My good friends who manage the AMS Device Manager brand brought this award to my attention. They also pointed out that three of the past four winners: PDVSA Petropiar oil refinery, Statoil Hydro Ormen Lange onshore facility, and Sasol Solvents and Olefins incorporate AMS Device Manager as part of their use of the HART diagnostic information.

If you're using HART-based field devices and would like some recognition for the innovative work to improve operating costs and increase plant availability, take a moment to nominate your plant.

MP3 | iTunes

Control Engineering magazine had a thought-provoking article, Commentary: Are you using wireless for control? Process industries editor, Peter Welander was at the ARC Advisory Group forum last month in Orlando. After hearing Emerson's Bob Karschnia present on the topic of wireless, Peter wrote:

Listening to the presentation, I could hardly believe my ears. "30% of wireless devices are being used in control applications." Did he really say that? The "he" in this case is Bob Karschnia, VP of wireless business for Emerson Process Management, arguably one of the largest suppliers of wireless process instrumentation and control systems today.

Peter quoted Bob in the types of applications where control was being performed:

Sure, people use wireless for monitoring applications, but about 30% of our wireless devices are in control applications. Some are open-loop control, meaning an operator will take an intervention, but they use it as a control point. Others are built into control strategies, but they're things that have longer time constants, like supervisory control applications, tank levels, temperature control of heated jackets, and things like that with slower time constants.

It didn't take long from when the WirelessHART standard was announced in September 2007 until the wireless devices and gateways came along. Next came the monitoring applications for applications like: spray water, remote pumps, moving rail cars, rotating reactor, wellhead/heat exchangers, temperature profiling/tank level, gross production headers, combustion engine emissions, benzene tanks, turbine units, pump vibration, rotating lime kiln, plugged filter detection, safety showers, wellhead maintenance, mobile/temporary networks, refinery management, roll bearing, and hot tanks.

Engineers, by nature, look for new ways to apply technologies in which they've gained confidence. It was only a matter of time before they built experience with the capabilities of these wireless devices and looked for applications beyond monitoring to include open-loop control and slower, closed-loop control.

An example might be a large, remote tank with a sight-only level indicator because of the expense in running cables. During operator rounds, the level is read and adjustments to the inlet and outlet flows are made. The reading might be made only once or twice per shift. An engineer might determine that one or two wireless level transmitters could provide readings back to the automation system for more frequent and smaller flow adjustments.

Most plants have several applications where the current practice could be greatly improved by the addition of a wireless measurement. If you're an engineer who came upon this post, I bet you're already thinking of at least one.

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The term "wireless" gets bandied about quite often these days among process manufacturers and automation suppliers. As process automation and IT professionals take an interest and look more closely, they begin to see different areas where wireless might be applied. Standards like WirelessHART for field device networks, asset management software and automation systems help provide interoperability.

Wireless plant networks, on the other hand, provide higher-level applications like mobile worker, safety mustering/personnel tracking, and plant video coverage to name a few applications.

I caught a sneak peek of an article written by Emerson's Neil Peterson for Canadian Process Equipment and Control News. The soon-to-be-published article, Choosing a wireless network provider? Look to a standards-based solution., offers guidance for incorporating a wireless plant network.

A key recommendation is make sure the wireless technology is compliant to the 802.11 standards for communications, security and quality of service. Neil notes that these standards are driven by the IT community and not specific to the process manufacturing industry. Choosing a solution that is proprietary causes "vendor lock in" and change comes at a price. If the vendor you rely on is no longer in business, you may be stuck without a good path to standards-based wireless solutions. Also, with a standards-based solution, the infrastructure costs can be shared among the various wireless application projects and plant departments that use this infrastructure. Many applications not economically viable with a wired solution become viable with wireless technology.

When executing a wireless plant network, Neil advises to look for a single-source contractor to integrate the standards-based solution to be responsible and a single point of contact for issues when multiple vendor products are involved. This selection provides choices on wireless devices and suppliers and competition on quality, form factor, ease of use, etc.

Unlike self-organizing WirelessHART field device networks, wireless plant networks usually require a radio frequency (RF) site survey to understand the challenges and obstacles to reliable wireless communications. The survey is important in the network architecture design and planning process to assure the required quality of service for the intended application. Neil offers a video application example where both the video application and the wireless equipment must support the quality-of-service provisions covered under 802.11e in order for the video to share the wireless network properly.

Neil sums up his thoughts that a standards-based approach to your plant wireless network infrastructure helps you to take advantage of new applications conforming to the standard as they become commercially available. With a proprietary approach, you're limited to what the supplier develops and when it gets developed.

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What's that expression... "Tan, rested, and ready"? After a nice holiday break filled with family, friends, and football (I'm in Texas after all!), it's time for me to dive back into the business of highlighting experts around Emerson Process Management.

I read a great piece in the AppliedAutomation supplement in the November 2008 issue of Plant Engineering magazine entitled, Asset management leverages smart wireless devices. Laura Briggs and Joseph Citrano, both managers in the Asset Optimization business, wrote this article.

Laura and Joseph made the point that all of the diagnostics that process manufacturers get from their HART devices connected to their asset management software or HART-enabled automation systems are also available from WirelessHART devices. They describe how Emerson's AMS Device Manager software has two-way communications through a wireless gateway to communicate this diagnostic information between the wireless devices and the asset management software.

Prior generation wireless devices used in monitoring applications typically did not support two-way communications. They would broadcast process variable information but not any associated diagnostics. Verifying the accuracy of the transmitted information required a trip by a plant technician to the device. For devices located in hazardous areas, this might also require work permits and sniffers to measure explosive gas concentrations. The authors note that the process typically takes a few hours and often no problems are found.

This troubleshooting process for both wired and wireless devices can take place in the maintenance shop or other area where the PC with asset management software is located. While devices with actual problems must still require the work permit, gas sniffers and other safety procedures, the "no problem found" instances can be eliminated.

Laura and Joseph also describe how this information can be used as part of a predictive maintenance program. Repair and replace decisions can be made based on the diagnostic trends from the devices. Also, device calibration schedules and device maintenance documentation for both the wired and wireless devices can be managed centrally.

The article highlights a wireless application at a PPG facility where wireless devices were used where it was too cost-prohibitive to run wire and conduit (estimated to cost $20 per foot.) The wireless network "came to life" five minutes after installing it.

To me, it sounds like a good thing to be quick to install, provide process information where none existed before, and provide diagnostics to simplify ongoing maintenance.

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Update: I was reminded of a great video Joseph has done showing the setup, management, and use of best practices for your wireless network using the AMS Device Manager.

Update: I made one clarification above that the article appeared in the AppliedAutomation supplement that came with the Plant Engineering supplement.

At this ISA Expo 2008 this past October in Houston, Texas, I had the chance to catch Dr. Kris Pister's keynote presentation, From Smart Dust to Smart Plants: The Evolution of Wireless Sensor Networking. Kris is the Founder and chief technology officer for Dust Networks, which began operations in 2002.

Beginning in the early 1990s, Kris saw the impact of Moore's Law on sensing, computation and communications technologies--ever falling costs and increasing power. He believed wireless sensor technology's size, power, and cost would also follow these trends and committed his energies to this pursuit.

His research led to the vision for "smart dust" in the late 1990s. The components included passive communications, sensing, thick-film battery, solar cell recharging, power capacitance, analog I/O with digital signal processing (DSP) and laser diode communications--mostly built with Microelectromechanical systems (MEMS) technologies. In his research at University of California at Berkeley, he and his research team had a working prototype by the end of the 1990s.

The team's work over the next several years was in the areas of ultra-low power and radio frequency (RF) communications. I had a great quote from his keynote in my notes, "RF is challenging. It's robust today because the team saw so many failures a decade ago."

The basis for the smart dust vision was cheap, easy, off the shelf RF systems. It had a wide cross-section of possible uses in academic, military, and industrial applications. Kris shared an example of an earthquake engineering research center where wired, seismic testing cost $5000 per node for real-time data acquisition. The cost per node with wireless seismic sensors was $200 per node. They had similar successes with temperature sensors in an HVAC application on the UC Berkeley campus, deploying 50 wireless sensors in 3 hours and reducing the cost per node from $800 (wired) to $100 (wireless).

For industrial applications, the team looked at research into the primary barriers for adoption of wireless sensor technology. The top four in order of concern were reliability, being standards-based, ease-of-use, and power consumption.

Recognizing the need for industry standards for broad adoption of new technologies, they are participating in several:

Dust Networks currently has leadership positions in several industry groups, including: the Wireless HART working Group (HART Foundation), the Internet Engineering Task Force (IETF), ISA's SP100.11 working group (ISA SP100) and the Wireless Industrial Networking Alliance (WINA).

Specific to the WirelessHART standard:

Dust Networks joined the HART Communications Foundation (HCF) in October 2005. Since then, Dust contributed its Time Synchronized Mesh Networking (TSMP) protocols and technology and collaborated with the HART Foundation and its member companies to develop the industrial automation market's first wireless standard for sensors.

In an earlier post, I discussed some of the diversity techniques used in the WirelessHART standard to achieve greater than 99.9% reliability to address this top concern among process manufacturers in the adoption of wireless sensors.

Kris also discussed their work on minimizing power consumption. Again turning back to my notes I captured this thought from the keynote, "Power- turning radios off is easy. Turning it on is hard... that's why time synchronized is so important. If all nodes in a mesh are within 0.1 msec, than A will wake up and listen for that length of time. A sends ACK to B. Keeps networks synchronized to 100 microseconds or so."

Nice, elegant design... let every device in a self-organizing network get their sleep to conserve power and make sure they wake together in a window of time to communicate and re-synchronize before their next nap.

A steady stream of news shows that Kris and the team's work on the vision of smart dust has paved the way for rapid adoption of self-organizing wireless networks across many industries and world areas.

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I had a chance to meet Emerson's Philip Schwarz a few years back in a multi-divisional marketing meeting. He had a slot on the agenda to discuss the trends in the oil & gas industry. He leads these efforts for Emerson Process Management's Rosemount measurement products. He was one, dynamic presenter, if you ever have a chance to hear one of his talks. Maybe I'll capture some video and post it in YouTube the next time I catch him presenting.

I saw an email from Philip where he mentioned that the oil & gas producers have been big adopters of wireless field device communications technologies. Philip noted around 9 in 10 of these oil and gas wireless applications were in onshore oil & gas fields. A big driver of this technology adoption has been for gross oil production flow monitoring applications.

The traditional way to measure gross oil production has been to use portable meter skids. These skids measure the oil, gas, and water content for each producing well on a site--when hooked up one by one. Since many fields are geographically dispersed, these measurements may be done one per month up to twice per year. After a well is tested, its production rate is assumed to be the last-tested measurement. It's important to note that these measurements are not to control the wellhead, but to monitor the production rates for each well.

Now, if five months have passed, this last-tested measurement might not be very accurate. And problems may have occurred in the subsurface well formation causing a production drop.

The main reason these wells have not been fully instrumented and been communicating continuously is the labor and installation costs of measurement devices, cabling, remote terminal units (RTUs), batteries, radios, etc. In many areas, these wells typically don't have the high production rates of offshore production wells. Hence, the traditional solution of a portable skid and schedule to conduct the flow measurements has been employed.

Wireless measurement devices and self-organizing WirelessHART networks have changed the economics by significantly reducing the infrastructure costs. To do the gross oil production measurements, these onshore sites install Rosemount 3051S wireless pressure transmitters and 648 wireless temperature transmitters. Instead of once per month or twice per year, each well can be measured on the order of seconds.

Communications between wireless devices can extend up to half a mile as the transmitters from surrounding wellheads self-organize to form a network with the wireless gateway devices. None of the cabling, cable trays, etc. is required, which significantly reduces the installation cost barrier.

Philip shared a 2005 Society of Petroleum Engineers (SPE) paper with me written by engineers with one of the major U.S. oil producers. It shared a vision of the digital oil field that provides real-time monitoring, analysis, and control for optimum field management. This vision included making the oil field more like a factory where there is a higher level of measurement and control to improve efficiency.

Technologies like WirelessHART self-organizing network communications and wireless-enabled field devices here in 2008 make possible many of the visions that were not economically justifiable when this paper was written.

Next time, a nice video of Philip talking about this will save around 550 words!

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I've known Emerson's Patrick Deruytter for many years. He's now the general manager for the Emerson Process Management office in South Korea. As his career has advanced, he's lived in many places--Minnesota and Texas in the U.S., Belgium and the U.K. in Europe, Australia, Singapore, and China. His experiences have included projects, project management, product marketing, lifecycle support, and general management.

He was in Austin last week and we had a chance to catch up. I found out he recently spoke at the Asia Pacific FPSO Summit with a presentation, Enabling Operational Excellence in FPSO. For those not versed in FPSOs, the acronym stands for Floating Production Storage and Offloading. When I worked in the offshore oil and gas industry in the mid-to-late 1980s, the overwhelming majority of offshore production came from fixed-leg platforms that set on the ocean floor.

Patrick highlighted some of the challenges and global trends for FPSOs. The first is the ever-increasing sophistication and complexity of the vessels and the onboard processing facilities. Oil and gas producers are building and modernizing FPSOs to meet the global needs for hydrocarbon-based energy.

Increasingly, FPSO owners want all of their systems integrated--navigation and propulsion systems, integrated automation systems (IAS), custody transfer systems (CTS), etc. Given the fast track nature of FPSO projects, equipment deliveries and skilled project engineers are critical for on time, on-budget performance. Once commissioned, the systems need to be highly reliable and easy to maintain, given the marine environment in which they operate.

Integrated systems provide a single window into the oil & gas production processes, subsea control processes, management of onboard assets, safety instrumented systems, and vessel automation processes (ballast control, offloading, power management, tank washing, etc.)

The design of the processing facilities on FPSOs is becoming extremely modular. This helps with the construction phase while the vessel is in the shipyard, and makes engineering, installation, and commissioning more manageable. The major processes like separation, gas dehydration, gas injection, oil metering, seawater treatment, power generation and distribution, custody transfer, etc. are pre-built, instrumented, and set on the deck of the vessel for integration with the automation and safety systems.

The modular trend extends to the wiring. FPSOs are moving away from large central control rooms toward remote I/O and control stations distributed among the production modules. This reduces the size of the total control room footprint, which is quite expensive on these ships. It also reduces cable runs, which reduces overall weight. And the modular design lends itself to modular pre-assembly and pre-testing which reduces overall commissioning time. Typically, the earlier you find problems, the easier and less expensive they are to resolve.

Patrick listed products across Emerson Process Management and alliance partners used in large marine projects like FPSOs and FLNG (floating liquefied natural gas) vessels. The list included DeltaV automation systems, DeltaV SIS safety systems, AMS suite software, Scanjet tank cleaning, Wärtsilä power distribution / engines / drives / vessel automation / propulsion systems, Rosemount tank radar level gauging and measurement, Fisher valves and regulators, Daniel metering and custody transfer, Micro Motion flow meters, and Valve Automation offshore valve systems.

These technologies have been applied in some of the world's largest FPSOs including ExxonMobil Kizomba A & B, BP Angola, Pemex, and Total, to name a few.

Patrick closed his presentation on WirelessHART wireless devices and how they are being incorporated in applications like wellhead annular pressure and heat exchanger pressure monitoring. This additional monitoring helps more quickly spot abnormal situations and reduces the manual clipboard and keyboard entry work processes.

The level of sophistication and technologies applied to these marine applications has come a long way from my days back in offshore oil production two decades ago!

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The HART Communications Foundation has published another WirelessHART white paper that describes various scenarios for low-latency PID loop control. The paper, Peer-to-Peer Communication with WirelessHART describes this transmission of information between network participants on a WirelessHART network.

This standard is designed to support applications like monitoring, diagnostics, alarm and event detection, and more complex data forms required for vibration monitoring, valve signature testing and process control.

A simple, cooling jacket temperature loop is the basis for five scenarios ranging from everything communicating wirelessly to everything wired in the field, but communicating wirelessly back to the WirelessHART gateway. The example loop includes a temperature transmitter, a control valve with a digital valve controller and a controller running in the WirelessHART gateway or process automation system.

The scenarios vary where the PID control resides and what devices in this control loop are hardwired.

For example, the first scenario has the temperature transmitter hardwired via a 4-20mA HART signal to the digital valve controller. Both these devices are wired to a WirelessHART transmitter that communicates back to the gateway. The PID control runs in the digital valve controller. Monitoring and setpoint changes are done via wireless communications from the process automation system.

Another scenario has the control running back in a process automation system controller or in the gateway with the transmitter and digital valve controller connected wirelessly to the gateway. The measurement value, valve target position and valve actual position communicate via the WirelessHART protocol.

There are power considerations if control is resident in one of the field devices. On way to address this is to run power as mentioned in the first scenario. The second way is to use the publish-subscriber communications built into the WirelessHART standard. From the whitepaper:

In WirelessHART, wireless devices are designed to support publisher-subscriber communications using multiple burst mode commands. Burst mode commands sent by the publisher (e.g. transmitter) are received by the gateway, cached, and then redistributed to the subscribing clients (e.g. valve) that are registered for notifications.

This burst mode communications happens on a periodic schedule and includes a timestamp, so that the other devices and applications subscribing to this information know its freshness. A WirelessHART Network Manager handles the security/encryption/validation of this communications along with the routing and scheduling.

The white paper concludes:

The WirelessHART protocol allows for secure, highly reliable, low latency control with almost no impact on the bandwidth and absolutely no impact on process performance. All of this is automatically built into the WirelessHART standard with little or no input from users. WirelessHART is simple, reliable, and secure.

Consider giving this white paper a read to see how you might apply WirelessHART to some of your low-latency control applications.

Update: I inadvertently picked up the wrong hyperlink for the whitepaper. Both links have now been updated. Sorry about that!

The ISA recently issued a press release around demonstrations of Electronic Device Description Language, EDDL (international standard IEC61804 and ANSI/ISA-61804-3) and FDT (ISA103) technologies at the ISA Expo 2008 in October in Houston, Texas.

For those not familiar with EDDL, I described it in an earlier post as a text-based language that is used to describe the characteristics of field devices. Following the EDDL standard, device suppliers create Electronic Device Description (EDD) files for their smart field devices. These files provide a standardized form and structure for automation systems and handheld communicators to access and display device diagnostic and setup information, independent of communication protocol or operating system.

Emerson's Terry Blevins has been working closely with other automation suppliers on the EDDL demonstration. He also is the ISA104 committee chairman. This committee has adopted the EDDL standard, IEC61804, as an ANSI/ISA standard. The release describes what will be shown in the ISA104 booth at ISA EXPO 2008:

The ISA104 EDDL booth at ISA EXPO 2008 is a demonstration by major DCS manufacturers such as Invensys, ABB, Siemens and Emerson that illustrates the technical strengths of the EDDL standard, IEC61804, to support advanced user interfaces for diagnostics and device setup independent of the communication technology support by the device. Devices such as valve position[er]s based on HART, Foundation Fieldbus, and Profibus from Metso, Samson, Invensys, Fisher Controls, and Siemens are used to illustrate how manufacturers are using EDDL to document their device capabilities in a single, open and consistent format. A live demonstration of diagnostic information being accessed using a WirelessHART adapter connected to a wired HART device and through wireless access to a self-powered WirelessHART device illustrates how EDDL supports the latest wireless devices.

The demonstration provides the exhibit attendees the opportunity to see the advanced interfaces for device diagnostics and device setup that are available from the major DCS manufacturers that use device EDD's. This demonstration will also show how the EDDL technology is by DCS supplier to provide interfaces to support wireless devices based on the WirelessHART standard.

In the release, Terry and the ISA104 committee also describe recent activities to continue to advance the IEC61804 standard:

International Electrotechnical Commission's Technical Committee 65 (IEC TC65) met in Tokyo, Japan, the week of 18 May. The working group responsible for the EDDL international standard, IEC SC65E WG7, met on 20 May and discussed future EDDL enhancements that will be incorporated into the existing standard, IEC61804. A number of guests from Japan and China that attended the WG7 meeting expressed an interest in learning more about EDDL. Thus, following the WG7 meeting, Christian Diedrich and Terry Blevins put on a workshop that provided more detail on EDDL and showed examples of how EDDL is used to write device descriptions.

If your plans include Houston the 14-16^th of October, make sure to stop by and visit with Terry and the other automation suppliers to see how this standard provides a common, interoperable way to present smart device information to you.

I've seen a number of stories about applications for wireless transmitters, but not for wireless valve monitoring. That all changed earlier this week when I received a Twitter direct message "tweet" from a colleague. For those not yet on Twitter, it's an option to send direct communications, unseen by others, when you have a reciprocal follow relationship with one another. It's like instant messaging but comes with the stream of others' short notes in your follow list. I have it set up where these direct messages come as text messages to my phone as well. I mention all this because it's another way communications are rapidly evolving from the world of email in which we've lived over the past many years.

The Valve magazine article, The Reliability and Security of Wireless Valve Monitors, is written by Emerson's Kurtis Jensen, an instruments product manager for Fisher and Valve Automation products.

One of Kurtis' closing paragraphs provides the primary reasons process manufacturers may consider wireless monitoring on some of their valves:

Most operations have a large number of "blind valves" that are either manual or semi-automatic but provide no valve position feedback, normally because of cost or location. As such valves age, their performance can degrade to sluggish, slow operation. The true position of the valve may be questionable, and operators have to start visiting certain trouble-prone valves to verify their position. Where valve position monitoring does not currently exist, wireless monitoring is a great way to start using this technology with minimum risk."

If you've ever come across the ModelingandControl.com blog, you'll know that sluggish valve performance is a contributor of deadtime that impacts overall control performance and plant efficiency.

As with any newly introduced technology, its ease of use is critical in its adoption. Kurtis notes that an upcoming release of a wireless position monitor product is non-contact and does linkage-less position sensing. After attaching and calibrating the device, it sends valve position information wirelessly across the self-organizing network to the automation system or asset management software.

He discusses some of the reliability and security aspects that I've described in earlier posts. The reliability aspects are largely to do with the self-organizing nature of the WirelessHART field networks. Alternative communications paths are taken from the devices to the wireless gateway when permanent or temporary obstacles happen.

Security is addressed in the WirelessHART standard and described by Kurtis through its changing encryption, message authentication, data verification and frequency hopping.

An important point made is that, "...wireless should not be viewed as a direct replacement for wired instrumentation." It's well suited for:

...hard-to-reach locations, in areas hazardous to plant personnel, where power does not exist and where running wires is not allowed or prohibitively expensive, to name a few.

This certainly opens up opportunities in many facilities to reduce the number of blind spots the operations staff face that must be covered by periodic manual inspection. The opportunities for wireless monitoring may be with the valves were early notification of performance degradation can help avoid overall poor control performance.

When I posted last week on WirelessHART reliability, I had a chance to speak to Emerson's Russ Muller who is a senior PlantWeb specialist. As we discussed the reliability figures, Russ mentioned that the sites that applied the best practices saw reliability figures much higher than 99%. If you've seen the PlantWeb University Wireless course, in the Wireless 203- Self Organizing Networks section, it shows this figure:

Even in this extreme example of low reliability links, by designing multiple paths for each device, a self-organizing network can reach that level of performance by constantly choosing the path that offers the best reliability at the time. With self-organizing networks, it's important to note that site surveys are not required. Russ shared with me some best practices learned from the early wireless installations which I'll pass along to you.

The first consideration is the size of your facility. If you have a large facility like a refinery or chemical plant, the wireless field network should be scoped to a single process unit. For vertically arranged facilities like power plants or some pharmaceutical sites, the self-organizing network should be scoped to a single floor.

Next, it is extremely helpful to have a scaled drawing of the single process unit or floor where the network will be installed. In an earlier post, I discussed the creative use of Google Earth to zoom in on an outdoor facility where they didn't have scaled drawings handy. These building drawings are typically available for inside facilities, which is a good thing since the satellite photos can't see inside a building... yet!

With the scaled drawing, plot the location of wireless devices. Consider the immediate ones you want to install as well as possible future ones. Every wireless device should have multiple neighbors to provide path redundancy for higher overall communications reliability. Based on the experience gathered from hundreds of installations to date, each wireless self-organizing network should be designed with a minimum of five wireless devices to provide this path diversity.

As you look at the devices plotted on your scaled drawing, it's ideal that each device have three neighbors as potential paths of communication.

Next, consider the placement of the wireless gateway. In small networks, the smart wireless gateway should be located in the center of the network. For larger networks or installations that require the wireless gateway mounted in a control or rack room, you should build the self-organizing network around the location of the wireless gateway, closest ones first, per your plot plan. Also, remember that the gateway needs to connect the network to your host automation or asset management system using common industry communications standards like OPC, MODBUS and MODBUS TCP.

The wireless gateway should have a direct wireless connection (connected without a hop through another device) to 25% of the devices in the self-organizing network. It will still be reliable if less than 25%, but greater than 25% is optimal. You can add wireless devices or repeaters to help achieve this best practice.

During installation, add devices outward from the gateway to reach other areas in the process unit. This installation process helps you see the devices as they are being added and helps verify the robustness of the communications.

I hope sharing these best practices in addition to the PlantWeb University Wireless courses provides you the background to try a wireless field network application in your facility.

I received a sneak peak of a white paper in the works by Dr. José Gutierrez, corporate director of technology with Emerson. This paper, based on the Why WirelessHART? article, discusses diversity techniques to achieve the reliability design objectives in the WirelessHART standard.

José begins with some history of proprietary point-to-point wireless "cable replacement" solutions. Data transmission was required for these applications but cables were not economically feasible to install. These wireless solutions also typically were not designed to scale.

Process manufacturers have been under constant market pressure to improve efficiency and productivity. This pressure has spurred innovations by automation suppliers on numerous fronts including advanced diagnostic algorithms, improved sensor technologies and improved communications technologies especially in the area of wireless communications.

In the 1990s, the U.S. Defense department invested in wireless communications research with high reliability, highly secure and extremely low powered design objectives. This basic research fed into future developments by leading industrial and technology companies on the IEEE 802.15.4 radio-communications standard for wireless sensor and actuator applications. José served as chief technical editor of the IEEE 802.15.4 standard.

During this time in 2003, the HART Communications Foundation started its wireless efforts that culminated in the release of the WirelessHART standard in the fall of 2007. This standard is designed to support a range of applications including process monitoring, process control, equipment monitoring, environmental monitoring, energy management, asset management, predictive maintenance and advanced diagnostics.

What makes this range of applications possible is the advanced diversity techniques designed to achieve reliability greater than 99%. When best practices like three or more communications paths per device are applied, the reliability is significantly higher--approaching 100%.

The WirelessHART standard employs five methods of diversity: time, coding, frequency, path and power. Here's my brief summary of each from the white paper.

Time diversity involves the use of intelligent data transmission scheduling to minimize collisions and recover from losses. WirelessHART uses synchronized time division multiplexing.

Coding diversity uses the radio spectrum where specific transmissions can be separated from noise and other simultaneous communications.

Wireless devices use frequency diversity (a.k.a. channel hopping) to dynamically choose different communications frequencies to avoid jamming or to mitigate interference from other wireless systems.

Path diversity comes from the self-organizing, mesh-communications network formation of wireless devices in a point-to-multipoint fashion back to the automation system and/or asset management system.

The final diversity technique used in the WirelessHART standard is power diversity where radio power transmission is controlled to a minimum level to destination devices to cut down on radio frequency noise for other devices using the same frequency spectrum.

I hope some of this background helps give you an appreciation for the techniques used to achieve high wireless communications reliability. The proof comes by giving it a try in your plant on measurements not currently possible or practical to wire.

Courtesy of Emerson's VP of wireless technology, Bob Karschnia, I received a draft copy of a whitepaper circulating about redundancy in WirelessHART device networks. It's not yet finished so I don't have a link, but here are some of the key thoughts I gleaned from it.

Redundancy, in this context, is defined as a duplication of critical system components to reduce the probability of a failure caused by a single component. This redundancy is available at three levels including the network of wireless field devices, the access points and the gateways to the control and/or asset management systems.

Starting with the wireless field devices, the WirelessHART standard supports communications redundancy through multiple paths (spatial diversity), multiple transmission frequencies (frequency diversity) and multiple timing possibilities (time diversity).

Consider a wireless temperature transmitter mounted in your process communicating with other wireless devices--say a pressure and level transmitter. This device creates a self-organized communications path through one of the other devices back to an access point or directly to a wireless gateway. If the path through this device is obstructed, the temperature transmitter will retry at a slightly different time, frequency and path to the other device. If it fails, it will retry--again adjusting time, frequency, and path.

As we discussed in an earlier post, Planning Your Wireless Instrument Installation, it's important that each wireless device have at least two other devices to communicate with to provide alternative paths when needed.

An access point is a specialized WirelessHART device with a high-bandwidth communication interface to the gateway. Multiple access points can be connected to the gateway to provide path diversity and increased bandwidth across the network. There is no limit to the number of access points in the field network.

At the highest level of the field network is the gateway, network manager software and security manager software. The network manager performs scheduling and routing services. The security manager performs security key generation and storage as well as field device authentication services. All three components can reside within a physical gateway or can be distributed in separate gateways.

Using a mechanism similar to redundant controller pairs available in most automation systems, primary/backup redundancy management is being developed and stress-tested for these gateways.

I'll keep a sharp eye out for the finished whitepaper and update this post with a link.

There's a great article on The Institution of Engineering and Technology's website, Industry Unplugged, by Emerson's Mike Ferris. Mike is with the Smart Wireless team in the Rosemount Measurement business of Emerson Process Management.

Mike's conclusion describes why process manufacturers might consider wireless field networks (a.k.a. wireless sensor networks.) He writes:

Wireless offers the ability to add additional measurement points to previously unreachable or unaffordable places throughout the process plant. This means greater access to information about the process and also the health of devices. Wireless mesh networking solves the problem of reliability within tough non wireless-friendly areas. Security issues have been addressed and in WirelessHART the process industry has an open standard to work with. By adding plant wide wireless networks it is now possible to improve the availability of this extra data to those that need it most.

Mike notes the adoption of wireless networks in our homes and offices and how it has become a part of our daily lives. This has not been the case in process manufacturing plant applications. A number of reasons he cites include a limited range of sensors and transmitters for acquiring data, security concerns, power concerns, and a lack of industry standards. Most wireless solutions were point-to-point, which prevented the ability to scale if the application required it.

These concerns led to the WirelessHART standard that I discussed in an earlier post. The architecture scales, installs in a straightforward way, and has well thought through security. For more on the underlying IEEE standards and protocols, this data sheet provides a good summary.

The main objective of WirelessHART is to be fully complementary to the wired HART standard. As such, it extends standard functionality like electronic device description language (EDDL) and provides process manufacturers a similar user experience whether the HART device connects wirelessly or via wires.

In the article, Mike offers application examples as opportunities where process manufacturers might give wireless field networks a try. I'll summarize his ideas in a bulleted list:

• Applications not justifiable when wiring installation costs included
• Remote devices in hard-to-reach areas
• Uninstrumented operational blind spots
• Existing HART devices with no way to deliver diagnostic information
• Manual readings done in hazardous locations
• Automating operator rounds
• Incremental measurement points
• Measurements on rotating or moving plant equipment (ex. lime kilns, rail cars, portable skids, etc.)
• Safety relief valve emissions monitoring
• Safety shower flow

Of course, many of these examples are possible. It's more the case that they are not practical once you factor in the wiring installation. It's kind of like your home. Some things are more trouble than their worth to do when wiring is involved. With a wireless option, things get a whole lot simpler and more doable.

I read Dick Caro's, Which Way Wireless article published last Friday on the ControlGlobal.com site. It discusses WirelessHART and ISA100.11a and their paths to standards. He describes ISA100:

ISA100.11a is the name of the first standard being developed by the ISA SP-100 standards committee. The committee was officially chartered in 2005, with an editing team created in early 2007 to actually write the standard. Completion of the standard's first draft is scheduled for November 2008, and it may be that this schedule will be met.

Let's check this schedule against past standards to get a reading of when products might be expected.

The only standards effort in which I was fortunate to participate was the original launch of the OPC standard--then called "OLE for Process Control." A task force with Microsoft in a consulting role and five automation suppliers: Emerson (then Fisher-Rosemount), Intellution, Rockwell Software, Opto 22, and Intuitive Technologies announced the initiative at the ISA show in October 1995. The objective was to create a real-time communications standard based on Microsoft's OLE and COM technologies. Emerson served as master editor for this initiative.

The first draft of the specification was released in December 1995 and a second draft in March 1996. Three global seminars were held to teach interested parties about the standard's scope from April through August of 1996. Version 1.0 of the specification was release at the end of August 1996.

A beta release of the initial DeltaV system came out late in the fall of 1996, and the general release occurred in the spring of 1997. It was one of the first, if not the first, OPC server and OPC client commercially available. From the announcement of the task force in the fall of 1995 to commercially available products in the spring of 1997, this has to be one of quickest standards development efforts in process automation history. This standard, now referred to as OPC-DA, is maintained by the OPC Foundation and is still widely used today as a way to integrate software, systems, and devices.

I think this effort progressed quickly because Microsoft technologies were becoming increasingly important in process automation solutions and the existing method of communication, DDE, had its limitations that most acknowledged.

I haven't been real close to the WirelessHART path to standard, so I called Terry Krouth, Emerson Process Management's Chief Technology Officer, to understand its path to a standard. The wireless portion came with the HART 7 specifications formally approved by the HART Communication Foundation (HCF) members last June and authorized for release by the HCF board in September.

The HCF launched the WirelessHART initiative in November 2004. Its objective was to establish a wireless communication standard for process applications and enable wireless access to existing HART devices whose installation numbers more than 20 million. More than 25 companies were involved in its development including most of the major automation system suppliers. This HCF whitepaper, Why WirelessHART, shows a timeline with the major milestones on its successful path to ratification.

Terry noted that while the WirelessHART spec was being written, an extensive field-testing program was designed and conducted. Hundreds of prototypes were installed in actual field conditions to verify that the specification correct and workable. To make sure the standard would meet its objective, use cases of application scenarios were developed to make sure the standard could be used. HCF also donated these use cases to the ISA100.11a effort in June 2006.

Just last month, Emerson announced it is taking orders for the first products compliant to the WirelessHART standard. This comes a year and a half after the first wireless field network products became available in October 2006. Like the OPC standard, it takes time once the final standard is ratified until products become orderable and commercially available from the automation suppliers.

Like the immediate value OPC standard created around interoperability, the WirelessHART standard is making around "hard to get at" diagnostic information. I've chronicled some of the successful applications like wellhead pressure measurement and tank farms level measurement.

Other applications that have been spotlighted include railcar temperature measurement, temperature profiling, hot strip mill water flow, and remote pumping.

WirelessHART-based field networks open up possibilities to provide diagnostic information that is not practical or perhaps even possible to get at with conventional wiring. Process manufacturers are quickly realizing the value when they install these networks as these examples demonstrate.

Update: I'd also like to point out a webcast, The Range of Wireless, that Automation World magazine is hosting. It will be held April 17, at 2pm Eastern U.S. time.

I received an email from Anand Iyer. He's a certified project management professional (PMP) and a project manager in Emerson's engineering center in Pune, India. His project experience covers the gamut from pharmaceuticals, bulk drugs and intermediates to oil, gas and petrochemicals.

He's sent me a paper he's written entitled, Collaborative Measurement Control System Engineering. It describes how measurements close to one another in the process can collaborate with one another to verify their operation. He describes an example around a distillation column:

Now let us take two temperatures (bottom temperatures) in a distillation column and a level measurement. When the level is normal, the two temperatures are same or have a fixed relationship between them. TI1 is placed at a lower level in the column (near bottom) and TC2 is at a higher level (and used for Temp. control). Now TC2 is generally used for control. We can safely say that if Level is normal, and TC2 is under maintenance, TI1 can be used for control (with a minor adjustment to Setpoint if required). Thus Level and Thermocouple TI1 put together can "collaborate" the measurement of Temperature-measurement TC2.

Anand contrasts the traditional approach to a failure with how collaborative measurement strategies can be used in control strategies to avoid outages or process disturbances. In the traditional approach:

...the first thing done if an element were to fail was to swap the elements (either during the shutdown caused by the failure) or by a planned outage or having the loop in manual and doing the swap. At times, we have also used our ingenuity and just swapped the wires at the analog inputs and tuned control setpoints to have the plant up and running in a very short time. And hopefully, in all that chaos, someone had the presence of mind to record the swap on the wiring diagrams.

Using a collaborative measurement strategy:

...says that if level is not low and TC2 is not available then TI1 can be a valid measurement. We alarm the operator that TC2 is not available, fine tune the setpoint if required... All this occurs automatically and there is no outage or disturbance that could result in quality issues.

He extends the thought to Foundation fieldbus devices where the final control elements themselves can perform the logical evaluations and select the available primary or collaborated measurement, increasing the overall robustness of the control strategy. Anand also extends his thinking to wireless devices and how they could be used in a collaborative measurement environment--not as a primary measurement, but as a collaborative measurement to check on other devices nearby.

I hope you'll give Anand's paper a read and add your thoughts.

Recently my Emerson RSS news Feed alerted me to a wireless application on a North Sea oil and gas platform. I sent a note to the team involved with this project asking about their perspectives.

I received great notes back from Jeremy Fearn, a Smart Wireless Specialist based in the United Kingdom and Rolf Jenssen, a manager in our Norwegian Asset Optimization organization.

The overall challenge this oil and gas producer faced was the desire to measure annular pressure of the wells remotely by replacing the local pressure gauges. These measurements monitor the integrity of the tubing and annulus in the area between the production tubing and well casing.

Now, from my days on oil and gas platforms in the Gulf of Mexico, I recall that adding pressure measurement around the wellheads can be difficult and cost prohibitive. As Jeremy points out, this requires cable tray, cables, installation, drawings, man-hours, transportation and accommodation of the team to do all this. Also, the areas around the wellheads are classified as hazardous areas.

The team found the easiest and least disruptive way to replace the existing local pressure gauges was to use a gauge adapter with the Rosemount wireless pressure transmitters. This provided a direct replacement of the manual gauges with the wireless devices.

Another challenge was the distance between the wireless gateway and the room with the automation systems and AMS Device Manager software. Jeremy described their solution to use the fiber optic option for an Ethernet connection to the gateway. A short length of fiber optic cable was used to connect from the wireless gateway to a nearby cabinet room. This room contained spare optical fibers, which allowed the team to connect through to the process Ethernet backbone.

The platform already had AMS Device Manager software used for on-line diagnostics of 125 valves equipped with HART DVC controllers. AMS Device Manager also included an AMS OPC server. This software pulled in all the wireless pressure readings from the wireless gateway. From here, the data was passed to an OPC client on the host automation system. The AMS software also tagged all the parameters in the wireless HART transmitters, making it easy to select a parameter showing the overall quality of the measurement. This meant the quality of the measurement also could be transferred to the operators on the automation system. For detailed information about the status, configuration and health of the wireless transmitters, AMS Device Manager with EDDL files is used, clearly showing any failures.

Rolf also noted that the automation system's OPC client during the set up uploaded all of the values and parameters available from the AMS OPC Server, taken from all the platform HART devices including the wireless devices. After the selection of the pressure, temperature and the overall quality value, the team deleted the whole upload, but the selected values for the OPC links were now updated continuously to the operators, included the annular pressure measurements.

Initially, the staff engineers thought that two wireless gateways would be required, due to the density of the platform and production equipment. It turned out that only one gateway was required. All devices were able to communicate with the gateway. In fact, the device mounted furthest from the gateway still found a direct path! As more devices are added in the future, the strength the self-organizing network will be increased from additional wireless signal pathways.

The team took two days less than expected to complete the installation, and the oil and gas producer's staff has performed similar installations on other platforms without help from Jeremy or the other wireless consultants.

The real benefit is that the annular pressured is monitored continuously by the operations staff rather than twice a day through manual readings. Pressure drop in the annulus might indicate a problem with the well. These continuous measurements provide operators an opportunity to take corrective action much earlier to help avoid well rework and lost production.

Dr. José A. Gutierrez is Corporate Director of Technology at Emerson. As such, he not only advises our wireless experts in Emerson Process Management, but also across the other Emerson businesses.

At the recent ISA Expo, he presented the paper, Reliable Wireless: Mitigating the coexistence Challenge. His key point is that through a number of communications diversity techniques, high communications reliability on the order of 99.9% or higher is achieved. These diversity techniques are supported the IEEE communications standards and are used in the new wireless field network standard, WirelessHART.

José had quite a bit of expertise to share and has a long history of participating with many standards bodies. Some of these include IEEE LAN/MAN, editor-in-chief of the IEEE 802.15 Working Group-Task Group 4, program manager of the ZigBee Alliance, board of directors' member of the Wireless Industrial Network Alliance, and chairman of the Networking Working Group of the ISA SP100 committee.

He began his presentation by defining the term coexistence from the IEEE 802.15.2-2003 Part 15.2 standard:

The ability of one system to perform a task in a given shared environment where other systems have an ability to perform their tasks and may or may not be using the same set of rules.

Collisions and coexistence issues can happen when two or more packets overlap in both time and frequency with sufficient energy to interfere with one another. Coexistence can be measured by the end-to-end message delivery success rate overall all operational conditions.

Different country's governmental regulations address the sharing of the radio frequency (RF) spectrum in different ways. The common approach has been in assigning different bands for applications such as TV, AM and FM radios, cell phones, toys to name but a few. You can get an idea of how these frequencies are divided with the U.S. frequency band allocation chart. A personal aside--it also makes for a great eye chart!

José discussed the unlicensed bands referred as ISM bands, short for industrial, scientific and medical bands. These bands are allowed for usage in a variety of applications and in some cases with worldwide availability. Only device certification is required for use in this band. Limits are imposed on the radiated power of devices transmitting at these frequency and they require governmental certification for the country in which they operate. These bands include 900MHz (902-928 MHz), 2.4GHz (2.4-2.4835GHz), and 5.7 GHz (5.725-5.875Ghz). For you non-electrical engineers, an Hz or Hertz is one frequency cycle per second. These unlicensed bands are very crowded.

The good news for process manufacturers is that the responsibility rests with automation suppliers to get their wireless devices certified for use.

The presentation covered the various ways information could be transmitted on these frequencies. It's enough for a future post, but I'll list some of the methods here: narrow band, frequency hopping, direct sequence spread spectrum (DSSS), orthogonal frequency division multiplexing (OFDM) and ultra wide band (UWB).

Tying all this back to coexistence, the IEEE 802 standard committee is the authority on wireless coexistence and ensures that these technologies will effectively coexist with all previous technologies.

José posed the question about what wireless suppliers can do to eliminate the coexistence challenge. The solution is to apply techniques that create diversity to mitigate this coexistence challenge. These diversity techniques include:

• Path Diversity: Mesh Networking
• Frequency Diversity: Channel Hopping
• Time Diversity: Time Division Multiplexing
• Power Diversity: Power control over multiple communication links
• Space Diversity: spatial location of sensing devices (not practical for WSNs)
• Coding Diversity: Use of advanced DSSS technology

The key for wireless field networks is to use a combination of these techniques to deliver the necessary high end-to-end message delivery success rate for reliable wireless operation. These diversity solutions used in IEEE-based standards applied in industrial applications including DSSS, OFDM, and UWB and used in the WirelessHART standard help eliminate coexistence issues as one of your considerations.

You can learn more about wireless basics, the technologies, cases for how they can be applied in plant applications and IT considerations by visiting the on-line wireless courses at PlantWeb University.

You may have seen quite a bit of news coverage (here, here) on wireless technology as it applies to plant instrumentation. At the recent Emerson Exchange, Emerson also announced some wireless news.

If you are an automation engineer, you might have thought about some applications where you would like to try this technology.

Your best course is to start with a simple business case. Perhaps the operators perform rounds to get readings from gauges and instruments not connected to the automation system. Having this information and associated diagnostics coming from wireless devices could possibly make your plant's instrument technicians more efficient.

I caught up with Mark Sagstetter in Emerson's Rosemount Measurement business. He recently went to a refinery along with John Biscone, a service technician in Emerson's Instrument & Valve Services business. Operator and instrument technician efficiency was the very business case this refinery was pursuing. Mark and John were contracted to provide their expertise to help plan the network and installation process of the wireless instruments and gateways. Much like the early days of digital bus technologies, this expertise can help automation engineers establish best practices for planning and executing future wireless installations.

In the course of a two-day site visit, they worked with the plant engineers and identified five process units including four tank farm locations that met the criteria for increasing operator and instrument technician efficiency.

My understanding when talking with Mark is that there are basically two overall best practices to follow when implementing a wireless field network. The first is planning the wireless network and the second one is the network installation.

When executing the best practice of planning the Self-Organizing wireless networks, Mark and John like to have scaled site drawings. Unfortunately, in this case, scaled drawings were not readily available. Necessity being the mother of invention prompted the team's great idea to use Google Earth to generate site maps. They used the printouts during the walk-through of these process units to help envision device locations, gateway locations, plot anticipated communications, and to help identify possible impenetrable situations.

As part of the best practice of planning the network, it is a good idea to plot at least two paths of anticipated good communications for each instrument. Using a color-coding scheme, with one color to mark anticipated good communications paths and another color to mark potentially interrupted paths of communication, John and Mark were able to use this process to help understand how the network may function when installed. It also helped to understand, plan for, and possibly eliminate possible pinch points and/or possible impenetrable situations before the actual installation.

With every Self-Organizing wireless instrument being capable of being a router (sending and receiving messages from other instruments), possible pinch points and impenetrables are easily overcome. This is accomplished with the addition of measured points or instruments that act as routers or range extenders.

During the installation-planning portion of the site visit, Mark and John recommended the plant engineers follow the wireless installation best practices. To do this, the plant engineers would need to power and commission the gateway first. Then install, power, and commission the instruments, starting with the instrument closest to the gateway and continue working outward from the gateway. The instruments' connectivity to the gateway should be verified each time after installing, powering and commissioning the instrument.

One thing I noted in my conversation with Mark is that the instruments mount with standard process connections. Engineers have been using these standard connections for years. The actual mounting location for the instruments and gateways were determined by providing a forearm's length (a measurement device every instrument technician has with them at all times) of space between the antennas and any wall or metal structures to avoid signal attenuation.

Installation would continue by powering, installing, and commissioning instruments outward from the gateway, until all the devices have been brought on-line. By installing the instruments in this fashion, the actual formation and connectivity of the wireless Self-Organizing network can be compared with what was expected during the best practice of planning the network.

Beyond the immediate need to help the plant engineers plan a smooth installation at this refinery, Mark and John helped them establish best practices to aid in future wireless projects/installations.

The ARC Advisory Group's Wil Chin has an industry trends report published today on Emerson's Asset Optimization group. The report, Emerson Asset Optimization Division Enhances Solutions, looks at the technologies and expertise this plant asset management (PAM) space. I've added hyperlinks in some of the quotes where more information is available.

In the area of plant connectivity with business systems the reports states:

...the Asset Optimization Division continues to add AMS Device Manager connection options to simplify the implementation of PAM solutions, such as wireless device connectivity, Profibus/HART interfaces, and motor starters and drives solutions.

Wireless smart field devices, a growing area of interest, is described:

...wireless field devices based on the soon to be released WirelessHART standard, which is now supported by virtually all automation systems and field device suppliers. ARC believes wireless field devices provide a low-cost conduit for accessing stranded diagnostic information to enable PAM solutions, and it is a low risk first step for manufacturers to experience wireless technology.

The wealth of diagnostics from smart field devices can take some thought on how to incorporate because:

...users struggled with updating hard-to-change maintenance practices despite their best intentions. Because the plant workforce is multitasking to the max, few available resources could be applied to the implementation and management of new technologies and best practices. PlantWeb Services were introduced to help clients get the most out of PAM investments.

Asset prioritization was one of the services cited:

...users want to know which of the asset health alerts are critical, ranked in importance to the performance goals of the enterprise. Asset Prioritization provides a systematic methodology combined with the domain experience of Emerson's professionals to quickly prioritize assets into a Maintenance Priority Index (MPI). The index is determined in a six step process that considers business criteria, asset criticality, operational criticality, probability factors and others to determine the MPI.

Machinery health was a final area described in the report:

...Machinery Health Management solutions consisting of high-end portable machinery health analyzers, machinery health transmitters, machinery health monitors and machinery performance monitors, which all integrate with the AMS Suite predictive diagnostics application, including to Emerson's Ovation and DeltaV control systems.

The combination of technologies to monitor the production process assets combined with experts who can work with process manufacturers to incorporate this diagnostic information into work practices provides a way to improve performance.

Control magazine provided excellent blog coverage of the recent ISA Wireless Summit. Control's editor in chief Walt Boyes in his post, Editorial Comment! offered his review of Emerson's John Berra's speech:

I just want to add that I am floored with the honesty and accuracy of what John Berra said this morning. He is exactly right. I want everybody to read what he said, and I'm going to ask him for the text of his remarks, so I can post them as an open letter on ControlGlobal.com. I hope he agrees.

John did agree and the speech text is available on the ControlGlobal.com site. Walt has blogged frequently on the efforts and difficulties in creating standards in the process automation industry. I'll highlight some of John's points from the speech.

John began with the benefits and noted that technology for technology's sake is not enough:

But if what we do as a technology doesn't transfer into allowing plants to run better, safer...it isn't going to survive.

Lack of information can lead to situations like unplanned shutdowns:

When you dig down into what causes unplanned shutdown, you find that it is usually the result of something quite simple, that we didn't know about. Most of the incidents that occur in plants can be traceable to things like that.

He discussed how wireless allows affordable access to information and offered the example of how wireless video cameras have provided affordable security solutions. In the process industries, manufacturers have installed 20 million HART devices, but "almost nobody has invested in the wiring needed to monitor these devices together." A wireless adaptor for these devices can free the stranded diagnostics and send them back to the control system to help see more of the plant and avoid situations like unplanned shutdowns.

With regard to the path to standards, John notes how competing standards like those that we see in the consumer space with Blu-Ray and HDVD slow market acceptance and the suppliers' recovery of R&D costs. John said:

Standards increase user willingness to buy. They give us confidence the approach we're taking will be accepted in the marketplace. But mostly, standards are good for our customers. That's why Emerson has supported standards efforts for a long time. We continue to contribute people, time, money and intellectual property. Our engineers are active in both SP-100 and WirelessHART activities. We have introduced pre-standard wireless products so users can start getting experience and benefits right away - but guaranteed that buyers will have a path to eventual standards. People ought to get started.

The development of standards has historically been a challenge in the process automation industry. John notes some of the experiences with the fieldbus standards development as an example. End user involvement is critical in the process to focus the efforts around the benefits and to develop the use cases for how the technologies will be applied. John recommended:

1. Move as quickly as possible to provide practical standards at the field level.
2. Take advantage of wireless standards already in place at levels above the field sensor network, and fill in the gaps.

On the first point, John notes that the HART Communications Foundation and ISA SP-100 committee have more in common than not. They agree upon the IEEE 802.15.4 radio and mesh network technology.

He urged the SP-100 team to take advantage of the work already done by WirelessHART and focus their efforts on the remaining portions of the standard.

John also noted that that the SP-100 team has role in addressing issues outside the IT-based wireless standards space in hardening, ease of use, and plant network management.

He summed everything up:

There's no question that arriving at a standard can be a struggle. But it's not about one faction or another winning or losing. It's about coming to agreement on how to make it easier for users to put this wonderful technology to work. And if we don't succeed, we all lose. The sooner standards are in place, the better for everyone. We need to get on with it. Suppliers will sell more products, and users will get more of the results that make wireless so valuable. The wireless potential of unlocking predictive intelligence so people can have a fighting chance to make their plants run better- this is what an automation professional is standing ready to deliver, and wireless is a key to delivering those benefits.

Update: Welcome readers of Gary Mintchell's Feed Forward blog! Gary points to Automation World magazine's Wes Iverson, who has a great summary article, High Interest, Slow Adoption for Industrial Wireless which includes his take on John's speech.

Update 2: Eric Murphy,at the OPC Exchange Blog, looks at John's speech and compares it with the efforts on furthering the OPC standard. Have a read of his post, Wireless and the Familiar OPC Story and add your thoughts.

I came across an email that the ISA Honors & Awards Committee has selected the paper, Improving PID Control with Unreliable Communications, for its excellence in documentation award. Emerson's Deji Chen, Mark Nixon, Terry Blevins, Willy Wojsznis and the University of Texas, Department of Computer Sciences' Jianping Song and Aloysius K. Mok wrote the paper.

The paper examines PID control in a wireless network where intermittent loss of communications is likely to happen. It identifies the poor dynamic response of standard PID algorithms in this loss of communications scenario. The team proposed an enhanced PID algorithm to improve dynamic response under these conditions.

Terry Blevins summarized the paper well in an earlier post on the Modeling and Control blog. The post, PID Modifications for Unreliable Communications describes the situation:

One of the technical challenges is that the 2.4 GHz spectrum defined by IEEE 802.15.4 is also used by Wi-Fi and Bluetooth devices. Also, some electrical devices found in industry generate noise in this frequency band. Thus, at times it is expected that a transmission will be corrupted. To help minimize the impact of these other devices on communications, the Time Synchronized Mesh Protocol (TSMP) selected for wireless HART uses frequency hopping. Even so, at times it is expected that multiple transmissions of a measurement used in control or multiple communications of control actions to an actuator may be lost.

Terry describes how the loss of communications can cause the PID loop to continue executing and wind up due to the reset action. This reset action can be disruptive to the control of the loop. And, if the derivative (the D in PID) action is used, the loss and resumption of the control measurement signal can cause a spike, again bumping the control of the loop.

The Emerson and UT technologists worked through a solution to minimize the impact of this loss of communications. Terry sums up the change:

However, by modifying the reset and derivative calculation to account for the time since the last measurement update, then it is possible to minimize the impact of loosing multiple measurement transmissions.

If you want to look at the math behind this innovation, check out the overview presentation, PID for Unreliable Communications, given at ISA 2006.

Congratulations to the team for their contribution to furthering the advancement of wireless technologies in process automation!

Walt Boyes, Editor in Chief for CONTROL magazine, has been closely reporting wireless technology and associated standards efforts in his Sound Off!!! blog. Some recent posts include:

Wireless-- who's to blame?
What about Wireless HART?
Are SP100 and HART Wireless Back on Track? Inquiring Minds Want to Know!
More Emerson Wireless
Bob Karshnia, from Emerson, speaks out on wireless
Emerson Declares Wireless...is it war?

Bill Morrison, Emerson Process Management Group's Director of Worldwide Marketing Communication responded to several of these which Walt posted in today's Emerson Speaks Out on Wireless! post.

A key point which Bill makes is:

Like several of our peers in the HART Working Group, we enthusiastically pursue the development of a standard. We openly share learnings gained from our trials with the Working Group. In fact, nearly 5 months ago (December, 2005), Emerson posted an open letter to the HART Foundation pledging our commitment to the donation of IP in an effort to further the standard. Our commitment to collaborate on a standard is clear, demonstrated through action.