Q3 • 2011
Old Machines,New DataYou Can Connect an Old Network to Your Modern Control or IT System. It Might Not Always Be Easy
p20 Signal Processing Drives Digital Networksp23 PoE Evolution Powers On • p27 Lose Those Stack Lights
IN11Q3_01_Cover.indd 16 7/26/11 12:14 PM
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1108-IndustrialNetworking-Communications-MAG:Communications 7/14/2011 4:46 PM Page 1
IN11Q3_FPA.indd 2 7/26/11 12:15 PM
©COPYRIGHT 2011 NEWPORT ELECTRONICS, INC. ALL RIGHTS RESERVED.
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C O N T E N T S
Signal Processing Drives Network DesignDigital Networks Enable Remote Signal Processing and Control via Intelligent I/O
BY DAN HEBERT, PE, SENIOR TECHNICAL EDITOR
Manage Your NetworkEthernet, Security and Safety Needs, and Increasing Network Complexity Call for More Managed Switches and Routers
7 FIRST BIT Hardware Rules, Software Drools
9 PACKETS Wireless Networking Breaking Down Barriers
12 BANDWIDTH Connectors in Unexpected Settings
13 BUS STOP DART Targets Intrinsic Safety
23 PARITY CHECK PoE—The Evolution Continues
27 TERMINATOR Remove the Stack Lights
COLUMNS & DEPARTMENTS
COVER STORY
20
INDUSTRIAL NETWORKING is published four times annually to select subscribers of CONTROL and CONTROL DESIGN magazines by PUTMAN MEDIA INC. (also publishers of CHEMICAL PROCESSING, FOOD PROCESSING, PHARMACEUTICAL MANUFACTURING and PLANT SERVICES), 555 W. Pierce Road, Suite 301, Itasca, IL. (Phone: 630/467-1300; Fax: 630/467-1124.) Address all correspondence to Editorial and Executive O� ces, same address. ©Putman Media 20110. All rights reserved. The contents of this publication may not be reproduced in whole or part without consent of the copyright owner. INDUSTRIAL NETWORKING assumes no responsibility for validity of claims in items reported. Single copies $15.
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52011 • Q 3 • INDUSTRIAL NETWORKING
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Old Machines, New Data
You Can Connect an Old Network to a Modern Control or IT System. It
Might Not Always Be Easy
BY DAN HEBERT, PE,SENIOR TECHNICAL EDITOR
O P T I M I Z E 1 4
IN11Q3_05_TOC.indd 5 7/26/11 12:18 PM
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IN11Q3_FPA.indd 6 7/26/11 12:16 PM
72011 • Q 3 • IndustrIal networkIng
Over the years, I’ve learned that the most important thing is often not the most obvious thing. For example, back in my general assignment reporting days, I discovered that the most important people in the circuit court and county offices in Cook County, Ill., were not the attorneys and politicians, but rather the clerks that kept each system running. and the big shots knew it, too, because I could see they kept up regular
deliveries of flowers and treats.likewise, also during the late 1980s, I met a young
lady and recent college graduate who had just started working at Goldman sachs in Chicago. she was no big-deal trader, but she quickly and almost unwittingly became one of the most crucial people there because she was assigned to be the person that coordinated the technicians that were needed to keep all the traders’ phones, communication networks and new PCs up and running. she was no engineer herself, but she got them where they needed to be. and she was rewarded magnificently because the financial giants knew their continued fortune depended on her.
Industrial networking hardware is just like these unassuming clerks and technical coordinators. at first, it looks like it’s not doing anything important, except for a few blocking indicators. But the basic platform and infrastructure it provides makes all of the world’s essential control and automation applications possible. Without networking hardware, all of software’s invisible ones and zeros would be lying around on chips—truly doing nothing. hardware is still the pathway that brings them into a useful existence.
likewise, point-to-point, 4-20 ma cable and connectors have evolved and sometimes been replaced by twisted-pair fieldbuses and wireless components. however, because they’re still moving data packets and information, even fieldbus loops still need plenty of wiring and ties to switches and routers. and what’s on both the transmitting and receiving ends of all those wireless links? you guessed it: more cabling. It seems that industrial networking is not without a sense of irony—and sometimes plenty of it.
similarly, I’ve learned that the moment I think nothing’s happening with industrial network hardware, I will find that I’ve jinxed myself and will immediately find a lot going on with its various
component-related technologies and applications. For example, while researching my techFlash column for Control design’s June issue, I was struck by all the activity and new materials being used to make wire and cabling.
“There’s been a lot of growth lately in the use of sensors related to more sophisticated automation, more components for new system installations and increasing use of intelligent
robots, and all of them need more and different types of cables and connectors,” reports dale long, industrial applications engineer at C&M (www.cmcorporation.com). “It’s not just power anymore. It’s communication and control, and so we’re seeing more demand for 600 v-rated, multi-conductor and fieldbus cables with some power.”
Frank Koditek, product manager for industrial cable at Belden (www.belden.com), adds, “ethernet is getting into more specific types of controls and electrical equipment manufacturing, such as switch gears and motor control centers (MCCs). These typically need neMa and Ul ratings, and so their cables need them, too. ethernet is also proliferating everywhere on the controls layer, and then down past that to the I/O layer and devices, such as machines, robots and other motion applications. so they need more high-flexibility, longer-life cables as well.” The same demands and trends can be seen in this issue’s Bandwidth column on connectors and cordsets, p12.
Perhaps because of these growing needs, many engineers, system integrators and end users seem to be waking up to the importance of their networking hardware. For instance, our managing editor for digital media, Katherine Bonfante, recently compiled research indicating a fairly huge increase in searches about industrial networking topics among visitors to our www.Controldesign.com website, which oversees our www.Industrialnetworking.net microsite.
In the first seven months of 2010, only one of the top 50 search terms on the website was network-related. It was “wireless,” and it placed 21st. however, for the same period this year, 11 of the top 50 internal search terms were clearly network-based, with “etherCat,” “ethernet/IP,” “Profinet,” “ethernet” and “Powerlink ethernet” falling into the top 20. not too shabby. top that, software.
Hardware rules, software droolsWithout netWorking
hardWare, all of
softWare’s invisible
ones and zeros
Would be lying
around on chips—
truly doing nothing.
hardWare is still the
pathWay that brings
them into a useful
existence.
Jim montagueexecutive editor
F i r s t b i t
IN11Q3_07_FirstBit.indd 7 7/26/11 2:57 PM
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92011 • Q3 • IndustrIal networkIng
PA C K E T S
wireless networking Breaking down BarriersIncreased adoptIon of mesh networkIng and Its self-healIng capabIlItIes could help to propel wireless networking to strong growth through 2015, according to recent research from Vdc research (www.vdcresearch.com). market growth has been strengthened by technology enhancements that help to overcome concerns over reliability, latency and security, analysts say.
growth of wireless networking in industrial facilities is driven by a variety of factors, however, including improved efficiency, cost reductions, increased productivity, and the ability to install wireless where wired solutions are impractical or impossible. wireless networking reduces the majority of the cabling required, along with associated costs; it also allows easier add-ons, changes and removal of functions.
despite the benefits of wireless networking, Vdc research does not expect the real emergence of the technology throughout the control hierarchy for most applications within the next five years, particularly for critical applications.
Vdc forecasts the market for wireless networking products (access points, antennas, gateways, modems, repeaters, routers, switches, transceivers and standalone network management software) to grow from less than $400 million in 2010 to close to $1.3 billion in 2015.
although data acquisition will remain the primary application served by wireless networking solutions, demand is growing most markedly for process, motion and logic control applications (see figure).
Fieldbus Foundation enhances specificationsthe fIeldbus foundatIon (www.fIeldbus.org) made enhancements to Its foundatIon fieldbus physical layer technology, and states that the latest updates to the h1 (31.25 kbps) physical layer specifications will improve the robustness of fieldbus control systems by optimizing device interoperability and integration. end users will benefit from improved installation, commissioning and startups.
enhancements include addition of a test procedure for isolated couplers to the existing foundation fieldbus coupler test specification, with registration of isolated couplers now possible; improvements to the h1 physical layer conformance test specification, the most significant changes including the addition of a receive jitter test case and a device-coupler interoperability test; updates to the h1 physical layer test specification to remove obsolete profiles and align new
The Mechatrolink Members Assn. (MMA, www.mechatrolink.org) reached a membership of 900 companies, including 50 in North America. Mechatrolink is an industrial network optimized for motion control, used most widely in Asia.
The CC-Link Partner Assn. (CLPA, www.cclinkamerica.org) released CC-Link IE Field Network specifications with integrated safety functionality. It meets international safety standards for SIL 3 compliance of IEC 61508:2010 for electrical, electronic and programmable electronic safety-related systems, and follows IEC 61784-3:2010 for functional safety fieldbuses.
The FDT Group (www.fdtgroup.org) and the International Society of Automation (ISA, www.isa.org) announced that the American National Standards Institute (ANSI, www.ansi.org) formally approved Field Device Tools (FDT) Technology standards—previously adopted internationally as IEC 62453 and approved in the U.S. by the ISA103 Field Device Tools Interface (FDT) committee. These U.S. standards now will be designated as ANSI/ISA standards.
The Fieldbus Foundation (www.fieldbus.org) released the new Flow Transducer Block Final Specification (FF-908 FS 1.0), which includes a standardized flow transducer block with a high-performance totalizer function.
Bits & Bytes
0% 10% 20% 30% 40% 50% 60%
DataAquisition
Motion Control
Other
ProcessControl
LogicControl
2010 2015
% of dollar volumes
WIreLeSS ShIPMeNT ShAreS
Although data acquisition will remain the primary wireless networking application, process, motion and logic control applications are coming on strong.
IN11Q3_09_10_Packets.indd 9 7/26/11 12:01 PM
references in the document with the current International Electrotechnical Commission (IEC) specifi cations, with coupler profi les also added to the specifi cation; and miscellaneous updates to the Cable Specifi cation.
“� e Fieldbus Foundation’s rigorous interoperability test and registration procedures thoroughly examine all aspects
of a fi eldbus device,” said Stephen Mitschke, Fieldbus Foundation’s director of fi eldbus products. “� e latest enhancements to our physical layer specifi cations will strengthen this testing and provide end users with greater confi dence that registered Foundation fi eldbus devices can be employed in a tightly integrated, interoperable control system architecture.”
Implementation of the new H1 Physical Layer Test Specifi cation Version 2.0 is not immediately required, although fi eldbus device developers are encouraged to start using the specifi cation as soon as possible. � e updated specifi cation will become mandatory with the next major release of the Fieldbus Foundation’s Interoperability Test Kit (ITK).
China’s Industrial Ethernet Sector Set for GrowthAS THE POWER AND ENERGY INDUSTRIES build in China, the market for Ethernet infrastructure components to serve those industries is booming as well. Nearly $120 million of industrial Ethernet infrastructure components were sold in China in 2009, and is estimated to show 20% growth for 2010 when all activities are reported, according to a new report from IMS Research (www.imsresearch.com).
“The Chinese market is still far from saturation compared with the industrialized world as a whole,” said analyst Alex Hong. “With many new plants and projects started recently, the demand for Ethernet components will continue to grow explosively.”
More than 30% of the Ethernet component revenues in China are coming from the power and energy industries, whose growth has been boosted by Chinese government policy, such as the Strong and Smart Grid Plan and strong support for renewable energy development. Transport and traffic is also an important vertical sector, the stimulation plan for infrastructure construction still having an effect on sales of industrial Ethernet components.
Although the oil and gas industry still has a relatively small user base for industrial Ethernet components, IMS Research considers the potential market growth in this sector very promising. However, certifi cation is important in these applications, analysts say, which could be an obstacle for Ethernet vendors.
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12 IndustrIal networkIng • Q3 • 2011
b a n d w i d t h Just when you think there’s probably not much happening with basic networking hardware, somebody starts a veritable renaissance in connectors and cordsets to serve new and growing groups of data-hungry applications.
“The biggest change for us in connectors is that they’re showing up in so many applications outside of factory automation,” says loreen katz, product marketing manager for phoenix Contact’s (www.
phoenixcontact.com/usa) plusCon industrial plug connectors. “These include renewable energy applications such as wind turbines, construction vehicles, firefighting and police vehicles, snowmaking machines and other outdoor settings, stages and stadiums, lighted signage, and some audio visual equipment. These applications previously used traditional hardwire, but in the past three or four years they’re using more pre-assembled, molded cable assemblies and M5 to M23 connectors. in the past, only carmakers and a few others used custom connectors and cables, but now everyone is getting into the ethernet and M12 act because they need to reduce the time and labor involved in putting systems together quickly without too much testing. however, to survive outside, many connectors are moving from nickel/brass to stainless steel internally, and then using uV- and ozone-resistant over-molding materials.”
steve loyal, business development manager for device connectivity at harting of north america (www.harting-usa.com), says the most significant trend his company sees is the shift to new machine and system designs that require eight-wire connectors and cables, principally ethernet, because users need more data at faster rates. “in the past couple of years, all new designs seem to need eight-wire connectors, even from standard i/o devices, for example, to manage data from Cat. 6a processes that could need 1 Gbps communications. This is where data rates and requirements are headed, especially to serve high-speed video cameras and vision systems inspecting high-speed production lines. This is being paralleled by growth in eight-wire, over-molded with pairs in metal foil (piMF), and braided-shield cordsets to limit interference, protect, and better manage those higher data rates.”
to assist these applications, harting recently
launched its X Code connector interface, which was developed in cooperation with Molex and phoenix Contact. X Code is an M12 connector with hardwired coding and shielded pairs to aid Cat. 6-level data rates. “we now have eight-wire connectors in M12 and rJ45, and both have standard form factors for easy installation, but deliver data at 10 Gbps,” loyal adds.
likewise, the promise of more and better data
via profinet inspired German automakers to ask their hardware suppliers to jointly come up with a standard connector, so they designed a common push-pull jacket around an rJ45 core and power wire. “it’s not often that competing manufacturers come together to demand a standard set of connectors, but this push-pull connector by the automation initiative of German automobile Manufacturers (aiDa) is a lot faster and less costly than all the different kinds of threaded and other connectors they were using before,” says helge hornis, product marketing manager for intelligent systems at pepperl+Fuchs (www.pepperl-fuchs.us).
“in general, as automation proliferates into more new industries and applications, there are a lot more inputs, outputs and control signals, and most also need to take up less space and use less power,” explains Cory Thiel, product manager for interconnect products at wago (www.wago.us). “This has meant taking our core spring-pressure terminator technology into smaller packages that are better attuned to the needs of different industries, and it highlights our strength in preserving signal integrity.”
as a result, wago developed higher-density connectors such as its 713 series double-row i/o interface connectors released about a year ago. to help industrial automation technology reduce costs in building automation systems, wago recently launched pico Max, european-style connectors based on Multi-Connection system (MCs) components.
“in the future, i think we’re going to see more variety in connectors and cordsets, but this means it’s going to be even more important for them all to provide reliable interconnections,” Thiel says. “if that foundation is solid, then everyone can respond quickly to all the needs that users will have.”
Connectors in unexpected settings“In the future, I
thInk we’re goIng
to see more varIety
In connectors and
cordsets, but thIs
means It’s goIng to be
even more Important
for them all to
provIde relIable
InterconnectIons.”
Jim montagueexecutIve edItor
IN11Q3_12_Bandwidth.indd 12 7/26/11 12:03 PM
132011 • Q3 • IndustrIal networkIng
B U S S T O PThe energy-limiTing requiremenTs of intrinsic safety (is) once led to serious limitations for process buses such as Profibus-PA and foundation fieldbus, where multiple devices are powered off the same cable pair.
A decade ago, is requirements limited these buses to fewer than eight devices per segment (network). since then, this has been improved through new practices such as the fieldbus
intrinsically safe concept (fisCo) and fieldbus non-incendive concept (fniCo), which allowed a high enough power budget to increase the number of devices permitted and simplify is calculations.
however, fisCo and fniCo have very specific requirements. Power supplies must be specifically designed and certified for fisCo or fniCo. Cable resistance, inductance and capacitance must conform to the fisCo/fniCo requirements. field couplers must be certified for the specific standard, and devices must be certified is for the zone and temperature limitations of the application. in addition, each segment must be documented, listing all the components above and their manufacturer, model number, method of protection, ambient temperature and temperature classification. The limitations on cable properties and available power (and hence stored energy) limit spur lengths (the distance from a coupler to a device) to about 100 ft, compared with almost 400 ft for non-is fieldbus segments. The power budget also limits the total devices, depending on their individual current consumption, to about 12 or fewer. fisCo and fniCo also require that only one segment power supply is actively powering the network, so redundancy isn’t trivial.
Physical layer suppliers have another solution for these limitations, employing a design called “high power trunk.” The trunk itself is not energy-limited, so live working isn’t possible without obtaining hot work permits. But the design does accommodate fully redundant, load-sharing, segment power supplies, and as many devices as the host manufacturer can support (typically 16). field couplers are fitted with energy-limiting circuitry to achieve the is requirements for each spur, and the required parameters for maximum stored energy are enforced from the field junction box to the device.
All these solutions achieve is by ensuring any
arc or spark from live working (e.g., installing or removing a device, or connecting test equipment leads) doesn’t have enough energy to ignite the area’s expected hazardous atmosphere.
But what if live working never created an arc in the first place? The engineers at Pepperl+fuchs asked this question a few years ago, and through the efforts at the consortium the company leads, developed a way to detect a developing arc and remove the
power the instant before it forms. This is dynamic arc recognition and termination (DArT), which can deliver dramatically increased power for weighing systems, lighting and automated valve networks, as well as Profibus-PA and foundation fieldbus, with the entire circuit meeting is requirements from the control house to the field device.
how does it work? P+f’s researchers saw that a very recognizable and repeatable phenomenon occurred every time an arc formed. They discovered it was relatively easy to detect a rapid increase in the rate of change of the loop current (di/dt), which preceded spark formation by a few microseconds. They also determined that spark current and voltage remained constant for another 1 to 5 µs thereafter, before the critical phase when a spark could form. The task, then, is to disconnect the power during the quiescent period after detection and before the spark forms, and then quickly restore it before any devices or communications are adversely affected.
Power supplies with this capability have been under development for three years, and tested and certified for use in is applications by PTB-Braunschweig. By the third quarter of 2011, P+f will begin to deliver DArT hardware for new projects. Acknowledging that the marketplace won’t tolerate a sole-source solution, P+f will offer to license the technology to other physical-layer suppliers.
in north America, agencies such as ul and fm still are evaluating DArT for installations covered by the u.s. national electrical Code (neC). DArT is certified for Zone 2 (equivalent to Div. 2, hazardous atmospheres normally not present), and Zone 1 (a subset of Div. 1, hazardous atmospheres normally present). The rest of neC Div. 1 is Zone 0, for which DArT is not certified. if users have applications for which DArT sounds like a great solution, be sure to have a chat with your electrical code expert.
What if live Working
never created an
arc in the first
place? dynamic arc
recognition and
termination (dart)
detects a developing
arc and removes the
poWer the instant
before it forms.
dart targets Intrinsic safety
John [email protected]
IN11Q3_13_BusStop.indd 13 7/26/11 12:04 PM
14 INDUSTRIAL NETWORKING • Q3 • 2011
The 1990s saw the demise of proprietary industrial networks and the emergence of open communication systems. Users embraced this new age of open networks, but now it’s time to
integrate those old networks into newer communication platforms, most of which are Ethernet-based.
Sometimes, integration can be done by just upgrading the PLC to a newer version. On the other hand, as one company reports, they spent more time making their new control panel communicate with a 1980s-era legacy network than they did writing the control code for the entire system.
� e pressure to integrate the plant fl oor with IT is one of the major reasons why manufacturers are searching for ways to connect to their legacy networks and extract data. But it isn’t always easy.
FAMILIAR REFRAINHere’s a pretty typical situation from � e Bradbury Co. (www.bradburyco.com) in Moundridge, Kan., which builds complete roll-forming lines, cut-to-length machines, coil-processing production lines, and automated production systems (Figure 1). “Many of our sheet-metal processing lines are still in production after 20 years,” says Larry Asher, controls engineering manager at Bradbury. “Over that time, IT and manufacturing departments have been working together and a highly integrated solution is sought by all, but not at the cost of a new production line. Today, our controls department is integrating new technologies and networks with our own legacy systems to meet the needs of our customers.”
In 1995, Bradbury released its fi rst computer-integrated manufacturing system. It had a DOS-based PC with a feed program developed in C. � e PLC communicated over Data Highway (DH+), the servo systems had their own network, and the I/O used DeviceNet.
Soon, customers began to ask for a better way to connect the production line to the office. Dynamic Data Exchange (DDE) was used on a Windows-based PC to exchange data with the DOS-based HMI software. A slew of networks, communication technologies and protocols came from various equipment vendors over the years. Many hours were spent trying to develop methods
BY DAN HEBERT, PE, SENIOR TECHNICAL EDITOR
Old Machines,New DataYou Can Connect an Old Network to Your Modern Control or IT System. It Might Not Always Be Easy
IN11Q3_14_19_CvrStory.indd 14 7/26/11 2:50 PM
152011 • Q3 • INDUSTRIAL NETWORKING
to collect information, ensure data integrity and make this data available to upper-level systems.
Four years ago, Bradbury began to develop an entirely new control solution based on EtherNet/IP. One goal was to maintain as much of the legacy systems as possible. Replacing functional and supportable components such as drive and I/O would make the solution cost-prohibitive.
Although EtherNet/IP works well on new systems, the problem of integrating older systems remained. Based on when the older unit was built, Bradbury uses different methods for integration. “Typical legacy systems will have a Rockwell SLC series PLC,” says Asher. “An SLC 5/03 or 5/04 will be upgraded to an SLC 5/05. We then will install an Ethernet-based network for the HMIs and the SCADA system, and use OPC to exchange data with the production line and the SCADA system. This provides integration to the customer’s ERP system. Some older systems might not have a PLC, and in this case we’ll use a PLC from the Rockwell Logix family of processors and add any required I/O.”
INTEGRATING WITH IT“One of our primary IT objectives at McElroy Metal is to provide an integrated information system for our employees,” explains Howell Hicks, IT director at McElroy Metal (www.mcelroymetal.com), a
customer of Bradbury in Bossier City, La. “We believe integrating our business processes enables us to achieve cost savings,
improved effi ciencies and a competitive advantage.”McElroy Metal makes metal roofi ng and siding
products. � e company’s operations include 12 manufacturing facilities, 18 service center locations and 40 Metal Mart locations. Connecting it all together was a challenge, especially when dealing with legacy networks.
“Integrating IT infrastructures with shop-floor technology is a challenge, since the methods, networks, operating systems and processing
components were developed through different channels for users and equipment with
different needs,” Hicks explains. “The resources and skill sets employed to keep an ERP system, email system and office productivity software operable and available on a network powered by Microsoft are quite different than those required to make controllers talk to PLCs.”
McElroy Metal wanted to port information entered into its ERP order entry system to its mill controllers, and thereby improve the overall effi ciency of the process. “� e eff ort to integrate our business software and data with
KEEP YOUR WITS ABOUT YOUGTech-HilTech, located in Conroe, Texas, builds equipment for the oil and gas industry, including decanter centrifuges, pumps and control panels. Key employees have 30 years of experience in the industry, so you would think the Wellsite Information Transfer Speci� cation (WITS) would be easy for them to integrate.
To appreciate this standard, you need to understand the mentality of the drilling industry, says Lee Hilpert, president. “When a drilling rig is built, it’s out� tted with the basic equipment required to drill a well,” he explains. “Other equipment is provided by service companies that deploy their specialized services on an as-needed basis.” So equipment comes and goes on a rig, and they all have to talk to each other. To make this happen, many drilling systems conform to the WITS standard, which is an old and slow serial network.
GTech-HilTech built a control panel for a local company, and had to provide a WITS interface for it. “We were amazed to � nd that you cannot just buy an o� -the-shelf device that converts data from our PLC to a protocol that’s acceptable to WITS,” Hilpert laments. “In fact, while it’s a very de� ned protocol, the implementation varies from job to job.”
They had to develop logic in a National Instruments cRIO controller to act as a gateway to the WITS protocol—and then write code to analyze the WITS structure, identify an open channel, and set up the gateway to propagate the information over the open channel in the proper WITS format.
“This panel was a communications nightmare just because the oil and gas industry is so slow to change,” Hilpert says. “Developing the logic to communicate took more resources than writing the code to make the equipment work.”
In the end, GTech-HilTech successfully implemented communications with the legacy WITS network, and it now has in place a standard hardware platform to integrate this unique network into the world of modern communications systems.
GTe
ch-H
ilTec
h
IN11Q3_14_19_CvrStory.indd 15 7/26/11 2:50 PM
16 IndustrIal networkIng • Q3 • 2011
our shop-floor software and data has been rewarding, but with great effort and considerable cost,” Hicks says.
Bradbury supplies most of the manufacturing equipment used by McElroy, and the two companies worked on this effort together. “We’ve been able to jointly develop interfaces that couple our IT infrastructure to our shop-floor controllers,” Hicks adds.
“The companies created joint testing labs at Bradbury’s facility in Moundridge, and at McElroy’s facility in Bossier City,” Asher says. “Those efforts allowed us to replace obsolete components such as DDE communications servers with OPC. Most of the solutions we evaluated simply required moving to an Ethernet-capable PLC. Over the last year and a half, we’ve retrofitted three production lines for McElroy Metal.”
Back to the 1990s—and BeyondGreg Lesniak is corporate electrical engineer for Tree Top (www.treetop.com), an agricultural cooperative representing apple and pear growers in the Northwestern U.S. It produces fruit juices and other products in seven production plants in Washington and Oregon, and also was dealing with networks from the 1990s. Lesniak was trying to gather process data from all its facilities, but ran into problems with legacy networks.
“Most of the processing lines are running automation systems put in place in the early to mid-90s, and many of those systems use legacy serial networks such as Profibus,” Lesniak says. “Further complications include standalone OEM systems that don’t talk to the main controllers without a large amount of effort, and the need to utilize the investment in legacy device networks for some period into the future.”
Lesniak went wireless by installing a newly developed PlantMesh wireless mesh Ethernet system from WingTip (www.wingtipllc.com) to gather the data. He connected the main network controller to a Cisco switch in the network room for the plant. Then he installed
MeshNodes in machine control panels and sensor panels.“The MeshNode is connected to an A-B CompactLogix PLC
through a Profibus interface via a ProSoft chassis card,” Lesniak explains. “The PLC has arrays defined by user-defined data types that the historian OPC server connects to and transfers data from. The PLC has three Profibus cards—one master and two slaves. The master controls I/O and VFDs directly, and the slaves transfer data from other Profibus networks. We have other A-B PLCs that have Ethernet ports or the NET NEI interface that A-B manufactures, which turns an A-B SLC or MicroLogix PLC serial port into an Ethernet-enabled port.”
With his plants having so many tanks, conveyers, piping and other metal obstructions, reflections and interference have the potential to make a wireless system difficult to use, Lesniak says. “But PlantMesh changes routes from our controllers when we have communications issues or node problems, and the system works well.”
even olderWhile Bradbury, McElroy and Tree Top deal with legacy networks that are 20 years old, one oil and gas drilling industry network goes back even further than that. The Wellsite Information Transfer Specification (WITS) is used to transfer well-site data from one computer system to another over a serial network. Lee Hilpert,
C o v e r s t o r y
The
Brad
bury
Co.
FIgure 1: a long runIn 1995, Bradbury released its first computer-integrated
manufacturing system. It had a dos-based Pc with a feed program developed in c. the Plc communicated over data highway (dh+), the servo systems had their own network, and the I/o used devicenet. soon, customers began to ask
for a better way to connect the production line to the office.
IN11Q3_14_19_CvrStory.indd 16 7/26/11 12:07 PM
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president of GTech-HilTech (www.gtech-hiltech.com) in Conroe, Texas, often works with WITS, and he’s not sure how old it is.
“In the 1980s, maybe even earlier, the drilling industry realized the need for a communications standard, as instrumented and networked devices became deployed on
drilling rigs,” he explains. “WITS was developed so various pieces of drilling equipment could talk to each other, and every company in the oil and gas drilling industry still conforms to it.” That means many new devices still have to connect to a network from the 1980s. See the sidebar, “Keep Your WITS About You,” to see
just how difficult this was.Friesen’s (www.friesensinc.com), based in
Detroit Lakes, Minn., manufactures material handling, check weigher and fluid power systems for the food manufacturing and packaging industries, and connects its modern systems to some older legacy networks.
Kari McAllister, director of product development at Friesen’s, says they have standardized on EtherCat for simple connection to essentially any Ethernet TCP/IP, serial RS-232 and CANopen device. “We can connect easily to a wide range of machines and devices while eliminating the legacy cards used in PCs, reducing cost and hardware size in the process.”
McAllister recently upgraded Friesen’s check weigher. “We wanted to process product weights faster and communicate to our reject systems at higher speeds, and at the same time provide connectivity to older protocols.”
Nathan Eisel, application support engineer at Beckhoff Automation (www.beckhoff.com), explains how his company’s hardware and software enables communication to various networks. “TwinCat software downloads configuration data to each EtherCat master/slave terminal, while the EtherCat network phases to operation (OP) mode,” he says. “Once in OP mode, data is simply cross-mapped from the legacy network to the EtherCat side of the terminal, and the data is transmitted back to the EtherCat master. All of this data can be passed over one standard Ethernet or fiberoptic cable, and we use XML description files to define how the master communicates with the slave.”
Keeping the Old SyStemReplacing existing equipment is expensive, notes Joe Sebastian, systems engineer and general manager at system integrator Optimation (www.optimation.us) in Rush, N.Y. “The main reason I see for keeping older networks is to maintain a large installed base of equipment that all uses a particular network,” he says. “To replace all the equipment at once would require a great deal of downtime and a large capital investment.”
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Sebastian cites an example of an existing Modbus Plus network that was maintained by integrating to a new Siemens Profibus network. “The manufacturer was standardizing on Siemens worldwide, but didn’t want to expend the capital required to replace existing automation components,” he explains. “The solution was to use most of the existing components. Where necessary, protocol converters were put in place and configured. This allowed the manufacturer to gain functionality immediately and upgrade remaining components later, on a schedule that its budget can handle.”
Over many years, the older automation components will be phased out completely. “Phasing out the old and gradually replacing it with newer technology will add to the lifespan of the equipment,” he says. “In addition, the upgrades add features that come with new technology.”
we’ll always have vendorsOne pretty basic way to connect to a legacy network is to go back to the vendor, says Richard McCormick, automation engineer at system integrator Mick Automation in Levis, Quebec. “Honeywell networks are covered by ‘proprietary integration,’” he says, meaning it’s embedded in their systems. “TDC 2000 Data Hiway to TDC 3000 LCN legacy systems are integrated through standard interfaces provided by Honeywell.”
The same could be true for your distributed control system (DCS) or PLC. If you have a legacy network, there’s a good chance that the vendor provides an upgrade path. Alternately, a third-party vendor can be used to integrate a legacy network.
Cindy Hollenbeck, vice president at SoftPLC (www.softplc.com), has a customer that wanted to keep its legacy DCS running, but migrate it to modern communications. “The legacy DCS system had Allen-Bradley Data Highway Plus communications,” she explains. “The migration desired was to Ethernet and a new I/O structure based on Profibus. The DCS communication options were limited. They used our SoftPLC product as a controller and a gateway between DH+ and the I/O.”
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20 IndustrIal networkIng • Q3 • 2011
With its ability to transmit large amounts of information quickly, a digital network enables remote signal processing and control via intelligent i/o. but remote i/o doesn’t make sense in all cases because it’s sometimes better to bring raw signals directly from sensors and dumb instruments to local i/o for centralized signal processing and control.
in the early days of remote i/o, a remote terminal unit (rtu) acted as a simple data concentrator. an rtu at a remote location gathered inputs from multiple sensors and instruments, packaged the data points in a “data frame,” and transmitted the frame to a central location via a proprietary, low-performance data network.
today’s remote smart i/o does much more than just gather, condense and transmit data—and much of its increased capability is enabled by modern, high-speed, two-way digital networks. smart i/o now performs many signal processing and control functions right at the i/o module, including real-time control. typical signal processing functions include filtering, high-speed counting, thermocouple linearization and more.
but smart remote i/o costs much more than local rack-mounted i/o—and networking this remote i/o back to a centralized controller also can add complexity, cost and overhead. is it worth the trouble?
Remote vs. CentRalized i/olantech (www.lantech.com), a packaging machine builder (figure 1) in louisville, Ky., uses both local hardwired i/o and networked remote i/o in its products, says Derek Jones, senior marketing product manager. The decision is based on the machine and the customer’s environment. sometimes the choice is obvious.
“our ring straddle shrink-wrapping machine has an elevator that carries a roll carriage up and down around a package,” Jones explains. “The elevator has 64 inputs and 16 outputs, and the i/o must be wired with flex-rated cable. The long, large bundle of expensive flexible wiring is replaced by remote i/o with a single flexible communication and power cable. The cost savings in wiring and labor from fewer cables makes this a clear choice in favor of remote i/o.” see the sidebar, “The Decision Process,” for a look at how lantech decides what to use.
“Wiring and installation costs for retrieving individual instrument signals from a remote unit are reduced considerably if you can
concentrate them at a location within the unit rather than having to wire all of them back,” advises richard mcCormick, automation engineer with system integrator mick automation in levis, Quebec, who sees advantages in both approaches.
mcCormick prefers centralized signal processing when the entire area of automation is relatively compact—that is when “a controller can be put in the middle of a relatively small unit, so the hardwiring is easier and not that expensive, making the total installation less expensive than one with remote i/o,” he says.
but deciding between remote and centralized i/o involves more than just reducing the wire count and installation costs because network performance also must be considered.
“There are trade-offs between remote and centralized processing in a distributed architecture,” says Curt Wilson, vice president of engineering
Digital Networks eNable remote sigNal ProcessiNg
aND coNtrol via iNtelligeNt i/o
signal Processing drives network designby DaN Hebert, Pe, seNior tecHNical eDitor
Lant
ech
stretCHIng I/oFigure 1: machine builder lantech uses both local and remote i/o in its packaging machines like this automatic stretch wrapper.
IN11Q3_20_22_Featr2.indd 20 7/26/11 12:08 PM
212011 • Q3 • IndustrIal networkIng
and research at Delta Tau Data Systems (www.deltatau.com), adding that one of the key determinants is the degree of interaction you wish to support between data sets from different remote devices.
“In one notorious case we’re aware of, one remote drive faulted in a system moving cassettes of silicon wafers through a semiconductor fabrication plant,” Wilson explains. “The information didn’t get back to the central controller via the network in time, and then from there to the remote drives for the other axes, so they continued to move. As a result, the system crashed and destroyed millions of dollars worth of microprocessors.”
In another case, a user had a system working, but was dissatisfied with the throughput. “By moving them to a system with more centralized processing, we were able to reduce cycle time by 30%, mainly by eliminating the delays from ‘Are you there
yet?’ queries and responses over the network,” Wilson recounts.
Improved network speeds now minimize such problems, Wilson says, with 100 Mbps
Ethernet-based industrial networks now common. “These
high-performance networks facilitate quick
interaction between remote nodes,” he adds. “Higher bandwidth and speed also greatly simplify system setup, diagnostics and repair.”
The Numina Group (www.numinagroup.com) in Woodridge, Ill., builds high-performance conveyor control and automation systems (Figure 2) using networked Beckhoff Automation (www.beckhoff.com) controllers and remote I/O. “EtherCat I/O is an order of magnitude faster than any I/O system Numina has ever used,” says Mark Woodworth, vice president of design. “This is important in high-speed sorters or sophisticated print/apply applications in which even a millisecond lag can be too much.”
With Numina’s previous I/O system, performance would degrade as the size of the application and number of required I/O increased. “Each time we polled a system of 20 modules or more, it took 25 ms, which wasn’t fast enough,” Woodworth says. “Now, we consistently get the industry’s fastest real-time speed, and we’ve seen no degradation in performance even with high I/O counts.”
Network reduNdaNcyMcCormick points out a problem that emerges when you compare the use of a centralized controller with remote I/O to having a local controller with its own I/O. “A drawback to using remote I/O is that a
D E S I G N
decision ProcessLantech builds packaging, stretch wrapping and pallet load conveying machines. Derek Jones, senior marketing product manager at Lantech, says the company uses both hardwired and networked remote I/O in its products, and the decision is based on the machine and the customer’s environment.
“Lantech uses several key points to determine if centralized I/O or remote I/O makes sense on a given machine,” Jones says. “The first deciding factor is cost. Is it cost-effective to place expensive remote I/O modules at strategic mounting locations on the machine, or is it less expensive to bring all I/O back to the main control panel?”
This can be determined by comparing the labor and material cost of routing more single-ended hardwiring to local I/O with the labor and material cost of remote I/O and its smaller overall lengths of double-ended cable, Jones explains. Overall cost will be determined by the number of I/O points, how far away they are from the main control panel, and how far away they are from each other.
“The second deciding factor is the available remote I/O technology,” he says. “Remote I/O is gaining momentum, but more complex I/O such as high-speed counters and motion control could be limited depending on the automation vendor. If the machine needs several functions not offered by remote I/O, this tips the decision back to centralized I/O.”
The third factor is the end-user environment where the machine will be maintained. “Remote I/O can simplify the wiring, but it requires more knowledge and understanding to set up and troubleshoot,” Jones says. “If the machine is being shipped into an environment where the end user doesn’t have expertise to troubleshoot or replace a remote I/O module, Lantech might not use this technology on the machine.”
CharaCterIstICs of remote networked I/o1. Provides best overall automation system
performance2. Reduces cabling and associated labor cost3. Easier to modify or expand4. Best solution for mobile or remote
applications5. Requires a digital data network6. Might require redundancy7. More complex than hardwired I/O8. I/O is more expensive9. Maintenance requires highly trained
technicians
CharaCterIstICs of CentralIzed hardwIred I/o1. Limits overall performance2. Simple to install3. Inexpensive for compact systems4. No network engineering required5. Easier to understand and maintain6. Wider variety of available I/O types7. Hardwiring back to central controller can
be expensive8. Not suited to mobile equipment or remote
installations9. Hard to modify or expand
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22 IndustrIal networkIng • Q3 • 2011
single point of failure caused by an electrical fire or other problem could take out the network communications link,” McCormick says. “This is why vendors normally offer redundant links from controllers to remote I/O, recommending different paths as much as possible. The second path could save a shutdown to the unit controlled with remote I/O.”
Charlie Norz, product manager at Wago (www.wago.com), agrees. “Network redundancy is an important design aspect, especially for critical applications,” he says. “Here, the focus should be on dual transmission paths for communication reliability in the event of a failure, such as a forklift severing a cable. Advanced controllers and couplers with this capability should be considered an integral network component.”
Redundancy is available on fieldbus systems, as Jim McConahay, senior field applications engineer at Moore Industries (www.miinet.com), points out. “A redundant device coupler accepts separate communications cables to increase the reliability of the communications cable in critical circuits should one of the cables become faulty.”
Wago’s Norz cautions that when using remote I/O for signal processing, the first design consideration should be network traffic reduction. “Performance is a primary concern with high-speed operations such as packaging lines, so don’t overlook traffic when designing for industrial applications,” he says.
Centralized i/O is simplerWith the sole exception of high hardwiring costs, centralized I/O on small control systems eliminates many of the networking problems and issues experienced by users of remote I/O.
“Centralized I/O requires no communication setup time for remote devices, such as distributed I/O modules,” says Lantech’s Jones. “All the I/O devices are wired directly to inputs and outputs, simplifying the engineering. Direct wiring uses single-ended cables that can be cut to length. Remote I/O requires double-ended specific length cables.”
Wadowick agrees. “Small systems can get by with centralized I/O and signal processing,” he advises. “If the machine footprint is just a few square feet, there’s usually no necessity to implement remote I/O.”
Automation systems with remote networked smart I/O are more complex to design, purchase and maintain than systems with hardwired I/O. However, the installation costs for remote networked I/O can be much lower, and the total system can operate at much higher levels because the remote I/O can perform many functions such as signal processing and real-time control.
In effect, an automation system that employs remote smart I/O interconnected via a high-speed digital data network results in multiple controllers distributed throughout the machine or process. These multiple controllers will outperform a single centralized controller, and in many cases will justify the investment and complexity of distributed signal processing and control via a digital network.
D E S I G N
a need For sPeedFigure 2: this conveyor control and automation system needed the performance and speed of the digital network etherCat to enable its remote i/O to perform at the required speeds.
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pa r i t y c h e c kAs I wrote In thIs column A yeAr Ago, Power over ethernet (Poe) certainly removes the single-cable constraint to using ethernet in the field.
As I stated then, a challenge faced by Poe for automation applications is that the 802.3af standard specified a voltage or 48 Vdc, while this industry standardized on 24 Vdc. At least one industrial ethernet equipment supplier has released a Poe splitter with a 24 Vdc output.
The Ieee Poe standards continue to evolve, so what’s the impact of “new” Ieee standards on industrial applications. here’s a highlight reel. A more thorough treatment can be found at www.Industrialnetworking.net/Poe.
Ieee 802.3af specifies that the current delivered to each node is limited to 350 mA. The total amount of continuous power that can be delivered to each node, taking into account some power loss over the cable run, is 12.95 w.
The updated Ieee 802.3at-2009 Poe standard, also known as Poe+ or Poe plus, provides up to 25.5 w of power. The 2009 standard prohibits a powered device from using all four pairs for power. some vendors announced products that claim to be compatible with the 802.3at standard and offer up to 51 w of power over a single cable by using all four pairs in the cat. 5 cable.
cat. 5 cable 24 Awg (0.205 mm²) has a resistance of ≤0.188 Ω/m—not very efficient in transmitting energy, which is why the power delivered by the power sourcing equipment (Pse) must be significantly higher than the power available to the powered device (PD). That means 12.95 w available to a PD from a 15.40 w Pse in the case of 802.3af; 25.5 w and 43.2 w, respectively, for 802.3at.
to manage PD currents, a Pse will start a timer that trips in 50–75 ms if the current does not drop back below the 15.4 w/Vport level. one consequence of this circuitry is that it limits the input capacitance of the dc/dc converter used in a PD. In addition, the Ieee specification says the maximum current a PD is allowed to draw is 450 mA. once the power has come up in the PD, there is a requirement in the Ieee standard to current limit the PD to 400 mA during normal operation.
Because there are devices non-compliant
with Poe+ and legacy Poe solutions developed before the standard was written or ratified, you must be careful when using Powered ethernet appliances. This should not be a problem in an industrial setting because we are used to verifying interoperability and in most cases purchase our equipment for a single facility from a limited number of suppliers.
In addition to the work being done to increase
the energy available on a cat. 5 cable using Poe, efforts are underway to reduce the total energy demand as well. energy efficient ethernet or Ieee 802.3az-2010, which was ratified sept. 30, 2010, is targeted at saving energy in ethernet networks for the popular 100BasetX and 1000Baset Phys (transceivers), as well as emerging 10gBaset technology and backplane interfaces, such as 10gBaseKr. The method of power savings currently planned for these Phys is a technique known as low Power Idle (lPI).
lPI provides for a lower-consumption energy state that can be employed during periods of low link use (high idle time). lPI allows for rapid transitions back to the active state for high-performance data transmission.
remember, ethernet is about the lower layers of the osI model and does not define the protocol doing the actual communications between devices. Just as when we make a phone call, often over our Poe-enabled IP phone these days, everyone on the call must be speaking the same language in order for communications to take place. the same is true for industrial ethernet and we have plenty of options available, each of them well-suited to the industry in which they are targeting—just be sure your selected hardware supports the software you plan to use.
Ian Verhappen is an IsA Fellow, certified Automation Professional, and a recognized authority on industrial communications technologies with 25+ years of experience predominantly in the process control field. Verhappen leads the global consultancy Industrial Automation networks, which specializes in industrial communications, process analytics and process automation.
In addItIon to the
work beIng done
to Increase the
energy avaIlable on
a cat. 5 cable usIng
Poe, efforts are
underway to reduce
the total energy
demand as well.
Poe—the evolution Continues
Ian Verhappen iverhappen@
industrialautomationnetworks.com
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24 IndustrIal networkIng • Q3 • 2011
R E S E A R C H
secure gIgabItEDR-G903 Firewall/VPN secure router supports three combo Gigabit ports with built-in RJ45 ports and SFP slots for connecting to a WAN, a LAN, and a WAN or DMZ. Dual WAN feature helps establish a reliable Internet connection backup and provides a secondary option for load sharing two ISPs. It supports intelligent firewall functions and Quick Automation Profile supports 25 common fieldbus protocols.Moxa; 888/moxa-usa; www.moxa.com
wIreless smartsSmart Switch industrial frequency-hopping Ethernet radios for 2.4 GHz and 900 MHz intelligently route packets, managing the wireless
network like a standard Ethernet switch, creating peer-to-peer wireless Ethernet communication. The radios provide long-range wireless connectivity and support 1.1 Mbps data rates. A serial port
can be used to pull data and send to a client via wireless Ethernet.ProSoft Technology; 661/716-5100; www.prosoft-technology.com/wireless
gateway to ethernetEthernet Remote I/O communication gateway and backplane enable LB/LB remote I/O to speak a new communication protocol as a
virtual bridge between traditional field instruments and Modbus TCP-based Ethernet with data transfer rates to 100 Mbps. A single gateway controls up to 80 analog or 184 discrete signals. The high transfer frequencies require LWL connections for long distances, while the copper lines are suitable for distances up to 100 m.Pepperl+Fuchs; 330/486-0002; www.pepperl-fuchs.us
gateway swItchBL20 Economy gateways for EtherNet/IP and Modbus TCP for distributed I/O have an integrated Ethernet switch that allows a line
topology between multiple gateways without using an external switch, eliminating the need for additional cable runs to the PLC. BL20 gateways accommodate up to 32 I/O modules and are available with an integrated power supply, eliminating the need for an additional power module to feed the I/O bus.Turck; 800/544-7769; www.turck.us
stratIxfactIonStratix 8000 and 8300 managed switches software Release 6 have enhancements to broken wire detection, precision time protocol and Smartports. New Stratix 6000 software
EthErnEt, SEcurity and SafEty nEEdS, and incrEaSing nEtwork complExity call for
morE managEd SwitchES and routErS
manage your network
MORE AuTOMATION PROCESSES MOVING TO ETHERNET-BASED control and a growing concern for network security and safety are leading to increasingly managed switch and router functionality.
A virtual local area network (VLAN) is an important function for managed switches, says Charlton Buck, product manager, North America, industrial communications and power networks, at Harting (www.harting.com). “As an example, you might want a packaging line to use certain ports—port 4, filling; port 5, washing; port 6, accumulation—to ensure your manufacturing batch process is not being accessed by potentially malicious users...or if you want to access a particular server without cross-traffic from other routers.”
Fully managed switches, used mainly where Ethernet is the primary automation control, also have applications in network redundancy and remote viewing, notes Mike Wightman, sales manager, fiberoptic products, at ultra Electronics, NSPI (www.ultra-nspi.com). Managed switches also can trigger email messages to a smart device in alarm situations, and can have self-healing ring (SHR) capabilities to keep the network up and running.
Managed switches can make better use of bandwidth. Having machine control on a network with VoIP phones or printers could slow traffic. “This is similar to using a 100 ft fire hose to water your tomato garden, wash your sports car, and put out a three-alarm house fire,” Buck says.
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252011 • Q3 • IndustrIal networkIng
features include spanning tree protocols, SNMP and VLAN trunking. The new release has added flexibility in building network architectures.Rockwell Automation; 800/223-5354; www.ab.com/networks
what’s Your lIne?BasicLine, ValueLine and PremiumLine unmanaged, lean managed and fully managed switches have options for Gigabit, Power over Ethernet and media conversion; IP30-rated metal housings; vibration-resistant construction; hazardous-area approvals; and extended operating range of -40 to 60 ºC.Weidmüller; 800/849-9343; www.weidmuller.com
swItch handles stressEight-port, EN50155-certified, IP67-rated EKI-6558TI and EKI-6559TMI
managed Ethernet switches with redundant X-Ring have watertight and weatherproof cases. EKI-6559TMI has two fiberoptic ports to guarantee interference-free connections and extend communication range.Advantech Industrial Automation; 800/205-7940; www.advantech.com/ea
edge swItchMagnum Power over Ethernet PES42 Power Source edge switches support up to four surveillance or access control devices as well as a fiber trunk back to a central control point. It has integrated ac/dc, 125 Vdc dual source, 48 Vdc dual source, 24 Vdc dual source, or integrated ac power input.GarrettCom; 510/438-9071; www.garrettcom.com
one for ManYcifX network controllers support EtherNet/IP, Profinet, EtherCat, DeviceNet and Profibus. Available in PCI, Mini PCI, CompactPCI, PCI/104 and PCI Express formats, the cards use the same software
host interface for all protocols, allowing quick and easy change of protocols by loadable firmware.Hilscher North America; 630/505-5301; www.hilscher.com
heal thYselfG408M fully managed industrial Gigabit Ethernet switch has a self-healing ring capability. When a fiber or cable break is detected on any of the ring ports, the switch reroutes network traffic in milliseconds. An alarm output on the terminal block can signal error conditions
to a PLC or other supervisory devices. Ports 1-4 are copper only; ports 5-8 can be copper or fiber.Ultra Electronics, NSPI; 512/434-2830; www.ultra-nspi.com
anY Port26-port 7026TX-AC rack-mounted switch for a 19 in., open-frame rack or machine cabinet features 24 10/100BaseTX copper interfaces and two Gigabit SFP expansion ports. 7026TX-AC accepts ac power for industrial machines; dc-powered 7026TX is aimed at conventional industrial applications. Both have N-Link redundancy and N-View OPC server.N-Tron; 251/342-2164; www.n-tron.com
fast recoverY10/100BaseTX to 100BaseFX managed, redundant industrial switch uses redundant copper or fiber links with switching recovery times
below 300 ms. The eight-port switches can be SNMP-managed via web browser to configure IGMP snooping, VLANs, QoS, port mirroring and trunking.Transition Networks; 800/526-9267; www.transition.com
gIge and fIberFL mGuard GT security devices provide all-in-one routing, firewall and VPN capability and support speeds to 1 Gbps. They support fiber as well as copper connections for application distances >100 m or in electrically noisy environments. With SFP connectors, a single GT/GT can work with single, multimode or long-haul fiber.Phoenix Contact; 800/322-3225; www.phoenixcontact.com/mguard
Integrated swItchAnybus X-gateway CANopen functions as a slave on the EtherNet/IP network and as a master on the CANopen side. The gateway is equipped with an integrated two-port switch on the EtherNet/IP side, enabling EtherNet/IP installations in bus or line topology without external switches.HMS Industrial Networks; 312/829-0601; www.anybus.com
deterMInIstIc swItchIngFast Track Switch technology prioritizes and accelerates the Ethernet
messages needed for specific applications. The identification characteristics of the messages are easy to configure within the switch, so important messages can be accelerated by the cut-through method to overtake other messages blocking their path.Harting; 847/717-9222; www.harting.com
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R E S E A R C H
Stack ‘EmEL326 Layer 3 rack-mount, managed industrial Ethernet switch provides 24 ports of Gigabit Ethernet and 10-Gigabit Ethernet uplinks. Advanced port security supports several authentication and encryption protocols, rate limiting and ACL features. Dedicated stacking ports enable the stacking of up to four switches, providing redundancy and added capacity as required.Sixnet; 518/877-5173; www.sixnet.com
GrEat StridESStride line of industrial-grade unmanaged Ethernet switches and media converters with
aluminum housings automatically determine and remember devices connected to each port and only route
messages through the appropriate ports, increasing speed and bandwidth, even under heavy I/O and data exchange.AutomationDirect; 770/889-2858; www.automationdirect.com/ethernet
GiGaBit EtHErNEtMach1040 19-in. rack-mount Layer-2 Gigabit Ethernet switch has 16 front- or rear-facing Gigabit Ethernet RJ45/SFP combo ports that support 100 Mbps and Gigabit transceivers. The rear-facing option provides a cleaner look and restricts unauthorized access to cabling. Four ports are available with power over Ethernet.Belden; 719/217-2299; www.hirschmann-usa.com
EtHErNEt SWitcHSeven-port 852-104 100BaseTX + Two-Slot 100BaseFX industrial managed Ethernet
switch provides multiple configuration methods, alarm contact to signal errors via email, event monitoring/reporting and port testing. The switch provides XPress
Ring and Jet Ring redundancy technologies for networking convenience and reliability. Wago; 800/din-rail; www.wago.us
SyNc your clockSEL6692 EtherCat bridge terminal improves synchronization for highly complex machines and production lines with numerous EtherCat masters. In the most complex systems, data may have to be exchanged between individual EtherCat systems, or the distributed clocks of different systems may have to be synchronized. The bridge terminal cost-effectively implements these tasks directly in the I/O system. In addition to normal data exchange, the EtherCat bridge permits distributed clock synchronization.Beckhoff Automation; 952/890-0000; www.beckhoffautomation.com
SWitcH QuicklyQuickSwitch 6259R RoHS-compliant, manually operated, 16-channel ST simplex fiberoptic A/B/Offline network switch has MEMS-based mirror/prism switch technology that supports Gigabit data rates. It allows devices connected to the Common port of each channel access to the A or B port on each channel. The front-panel LED display indicates all of the switch positions and unit power status.Electrostandards; 401/943-1164; www.electrostandards.com
StaNdS aloNEStandalone Ethernet hub for X20 slice I/O can be used as a 4x or 6x hub or even 2x hub for extending Ethernet sections up to 200 m. In addition to standard Ethernet,
the modular hub can be expanded with an X20 bus controller module with an integrated 2x hub for Ethernet Powerlink.B&R Industrial Automation; 770/772-0400; www.br-automation.com
A d i n d E x
Advertiser pAge no.
Automationdirect .................................................2
Beckhoff Automation ...........................................8
CC-Link .................................................................. 17
garrettCom ........................................................... 22
Hilscher north America .......................................6
HMs industrial networks ................................. 10
Moxa technologies ...............................................4
newport instruments ..........................................3
prosoft technology............................................ 18
sealevel systems................................................. 19
transition networks........................................... 28
turck ........................................................................ 11
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26 iNduStrial NEtWorkiNG • Q3 • 2011
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272011 • Q3 • IndustrIal networkIng
t e r m i n a t o r
The holy Grail:
inTerconnecTinG
machines and
sharinG daTa such
ThaT The enTire
producTion line
is aware of The
sTaTus of each of
iTs dependenTs, only
alerTinG personnel
To excepTions
requirinG manual
inTervenTion.
Here’s my cHallenge: remove every stack light from every machine on your factory floor. make your machines smart enough and build your plant infrastructures such that those lights are unnecessary. Does that sound possible or feasible?
control Design’s “let the machines talk” (www.controlDesign.com/talk) article forced me to ponder this notion. given the very attractive price points of industrial-grade networking hardware,
the range of selection, and the ease with which many things now connect—think wireless here—why aren’t more machines “aware” of their own surroundings? The hardware to do it is available, and the majority of it works very well. From sensors to devices to controllers to safety components, the networking problems associated with exchanging data and sharing information are largely solved—that is, at least from a hardware perspective.
Isn’t it better for upstream equipment to know that the downstream palletizer has a pusher jam, rather than just knowing that the out-feed conveyor is backed up? armed with knowledge of the pusher jam, the other equipment can make better decisions on what to do or not to do. This decision could be as simple as each part of the line using all of the conveyor buffer space in order to continue producing. or, based on data about units left to produce, and current raw material remaining, it might be best to immediately send a text message to maintenance personnel so they arrive prepared. armed with good data, it might be the machine that tells the operator or service folks what to do next, rather than the other way around.
I think that’s the Holy grail: interconnecting machines and sharing data such that the entire production line is aware of the status of each of its dependents, only alerting personnel to exceptions requiring manual intervention. all other events are handled by sound local decisions based on awareness of the rest of the line. note: The machine can be constantly aware; the operator needs to do research to have current information at his or her disposal.
certainly, the reasons behind events that occur during a production run would be nice to see in oee dashboards, or in key performance metrics (kPms), and that information certainly would help with predictive maintenance. For example, knowing that the incidence of that pusher jam
correlates tightly to a certain group of products—or a set of products running at a particular rate—could be something that’s not intuitively obvious. It’s hidden from casual observation, but perhaps is the single key to solve a nagging problem. a machine aware of its own surroundings has that information available. The analyses can happen on their own; no need to manually overlay data, parse reports or evaluate evidence.
so why is it that this intelligence isn’t the norm? a process implies a pre-determined set of steps to
accomplish something. That “something” is defined, known and readily available. “machine,” in contrast, implies certain specificity. often, we think of it from the perspective of the dedicated task it serves. It is, however, commonplace for a machine to exist as part of a larger process, while the controls remain targeted to the machine, rather than to production capability. a machine usually only has certain input expectations, rather than the smarts to deal with things that fall outside them.
It’s that mindset—failing to focus on the production capability—that needs to change. capability is what a machine provides, but that capability is only realized when inputs are available for use and outputs can be received. knowledge of both is very important, but we usually think of them as discrete, rather than continuous. Process automation sees things as continuous, which is the way machines should, too.
machines need to exchange data to do it. In today’s world, a Pc that is placed on the plant floor is almost always connected to the corporate intranet, thereby possessing the ability to get and give data. many expensive production machines in those same areas are connected to each other with only a conveyor. very few exchange live data. It simply doesn’t make sense.
When we talk about getting rid of the lights, it forces us to view the machines and the roles they serve differently. It also tends to push us in a direction that leads toward smart, highly flexible, productive facilities. remember, it’s not about how fast we produce; it’s about how effectively we produce.
Jack chopper is chief electrical engineer at Filamatic (www.filamatic.com) in Baltimore.
remove the stack lights
Jack [email protected]
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