FuRIOS 2Fieldbus and Remote I/O System Comparison

PrefaceProf. Dr.-Ing. Birgit Vogel-Heuser,Institute of Automation Technology/Process Informaticsat Bergische University Wuppertal

Preface to second, updated editionProf. Dr.-Ing. habil. Lothar LitzInstitute of Automation TechnologyTechnical University Kaiserslautern

FuRIOS: Fieldbus and Remote I/O – a system comparisonPublished in atp – Automatisierungstechnische Praxis 44 (2002),Edition 12/2002, pages 61 - 70

Dr.-Ing. Thomas Tauchnitz, Aventis Pharma Deutschland GmbHDipl.-Ing. Wilfried Schmieder, Aventis Pharma Deutschland GmbHDipl.-Ing. Sven Seintsch, Infraserv GmbH & Co Höchst KG

Fieldbus and Remote I/O: System Comparison „FuRIOS“Presentation at the NAMUR general assembly, 08.11.2002

Dr.-Ing. Thomas Tauchnitz, Aventis Pharma Deutschland GmbH

Fieldbus Experience ReportsPresentation at the NAMUR general assembly, 04.11.2004

Martin Schwibach, BASFThomas Meier-Künzig, DSMSven Seintsch, infraserv höchst technikDr. Joachim Zobel, Novartis

Push-button telephones were the first step on the way to the mobile phoneInterview mit

Dr.-Ing. Thomas Tauchnitz, Aventis Pharma Deutschland GmbHManfred Dietz, Infraserv GmbH & Co Höchst KG

Savings are not the goal of fieldbusInterview with

Frans van Laak, Speaker of NAMUR working group 2.6 „Fieldbusses“Harry van Rijt, DSM TechnoPartners

From theorie to practical useAventis applies FuRIOS study in real pharmaceutical plantRound Table with project participants

FuRIOS Fieldbus and Remote I/O System Comparison

Opinions“In the meantime the advantages of the technology are undisputed”

Dr. Oestreich, Managing Director Profibus Nutzerorganisation

“A manufacturer can obtain enormous benefits from this technology“Richard Timoney, President Fieldbus Foundation

“Fieldbus technology is mature enough for practical use“Martin Schwibach, BASF, Speaker of NAMUR AK 2.6 „Fieldbusses“

“Already today, users are clearly deciding in favour of fieldbus“Marc Van Pelt, Vice President Europe Fieldbus Foundation

“With fieldbus, we have got all this marvellous information with its huge potential”Ian Verhappen, Chairman Fieldbus Foundation Enduser Advisory Council

“Things are looking good for fieldbus“Dr. Joachim Zobel, Senior Automation Engineer Novartis Pharma

Fieldbus is getting its wingsPublished in MessTec & Automation 12/2004, page 62 - 64

Dr. Christine Eckert, journalist

Fit for the futureFieldbus technology at ClariantPublished in CHEManager Edition 7, April 2005

Dipl.-Ing. Michael Pelz, Clariant GmbHDipl.-Ing. Thomas Eichhorn, Clariant GmbH

The applicability of the FuRIOS StudyPublished in atp – Automatisierungstechnische Praxis 45 (2003),Edition 3/2003, pages 51 - 54

Dipl.-Wirtsch.-Ing. Thomas Kasten, Pepperl+Fuchs GmbH

Less handicaps in explosion hazardous areasPublished in P&A Magazine Edition 1, March 2005

Dipl.-Wirtsch.-Ing. Thomas Kasten, Pepperl+Fuchs GmbH

High-Power Trunk Concepts –with FieldConnex® Fieldbus Installation Technology

Presented with the kindest greetings from:Pepperl+Fuchs GmbH www.fieldconnex.info

FuRIOS 2 Fieldbus and Remote I/O System Comparison

Preface to second edition

The break-through of Fieldbus in Process Automation – do we see it now?The possibility of technical realization has been proven for some time now: Fieldbus based solu-tions for automation of process production plants in explosion hazardous areas. We all know thata break-through does not automatically and immediately follow the technical realization.It took almost 10 years from the first Process Control System in a pilot plant to its routineoperation. The break-through was somewhen in-between. How long is this way for Fieldbusand where are we today on this way? The first test and laboratory installations of fieldbushave been long ago. The first production plants are in operation now, several more are beingcommissioned today. Even more are in the design stage. Do we see the break-through? It certainly looks this way.The right evaluation at the right time: FuRIOS (Fieldbus and Remote I/O System Comparison).Nine manufacturers participated in this study which was conducted under the lead of anuser company. It was the right time for this study since, with fieldbus barriers, segment couplersand valve boxes, it was able to include the latest technical developments. Without thesethe comparison of economic efficiency would have been in favour of Remote I/O. SimilarlyFuRIOS was the right study since it asks and answers all essential questions in a very methodicalway. The manifold advantages of Fieldbus over Remote I/O are described in all details.Especially one important condition got not forgotten in FuRIOS: The long-term availabilityof the new technology. In terms of investment protection this is essential for productionplants since – typically for process industry – they are in operation for at least 25 years.Ultimately long-term availability is one of the major differences to Fieldbus in factory automa-tion, were the break-through took place during a few years only, and this was several years ago.Studies like FuRIOS are essential milestones on the way to break-through. It finally takesplace when people do not write about it any more, but when the acceptance is proven by theincreasing number of fieldbus-based plants. The principle of positive feedback, known toevery process control engineer, will help. Any break-through profits from feedback, without ita break-through is hardly possible. A major argument for an investment decision is the economicefficiency. Lower investment costs for a new technology lead, due to economies of scales, to aprice decrease and therefore to further reduction of investment costs. Each new plant working onfieldbus is part of the proof of acceptance and therefore an important step on this way. Each oneof these plants is a part of the break-through, which we indeed see today.

Prof. Dr. Ing. habil. Lothar Litz March 2005Institute of Automation TechnologyTechnical University Kaiserslautern

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In contrast to the Remote I/O systems, which have reached a wide market penetration within fewyears, the technically superior Fieldbus does not see a market breakthrough yet. It is frequently saidthat the Remote I/O system achieves almost all advantages compared to the conventional cablingof field instruments so that the move towards Fieldbus does not pay any more. On the other handRemote I/O systems are often seen as interim solution. In order to help clarify this contradiction thecompanies Aventis and Infraserv performed a system comparison of Remote I/O and fieldbus incooperation with the IGR (Industrial Practices Interest Group, see www.igrtechnik.com) and sever-al instrument manufacturers. The project name FuRIOS (Fieldbus and Remote I/O – System com-parison), in German language associating “race”, might provoke exaggerated expectations. Theresult, however, is that the Fieldbus is superior to Remote I/O in many aspects: It brings further sav-ings in investments, accelerates project execution and startup and so provides the migration to anew technological platform that enables the development of innovative and attractive instruments.Manufacturers and users are encouraged to make intelligent use of these new opportunities anddo more than just transfer the conventional instruments and operations without modifications tothe Fieldbus.

1. Introduction

Mature Remote I/O systems have been on the market forseveral years. Many companies have made extensive use ofthis technology in new production plants, allowing it toprove its worth in extremely large and complex applica-tions. It has demonstrated that it is a “feasible method”,see (1). The cost savings in comparison to conventionalwiring using field distributors, multicore cables and patchcabinets are huge. Certain disadvantages, such as in theplant-specific structure, in physical location within theplant, a more complex configuration and additional train-ing requirements, are accepted.The situation relating to fieldbus in the processing indus-try is entirely different. For many years, the competitionbetween several fieldbus standards only confused equip-

ment manufacturers and users. In addition, there weretechnical problems and bottlenecks. However, since theinternational standardisation came to a temporary finishwith the ratification of IEC 61158 (2) and with Profibus PAand Foundation Fieldbus two systems are now on offer forthe processing industry, the technical base for the use ofthe fieldbus is now given. There is a large offering of field-bus-capable devices, while certification centres offer theirservices.In a technological sense, fieldbus is one generation aheadof Remote I/O systems. The field signals can be transmitteddigitally, in the same format as they exist in the field deviceanyway. The elaborate and often fault-risky conversion intoan analogue signal and back again is no longer necessary.Diagnosis data can be transmitted without difficulty alongwith the measurement signal and need not to be encrypt-

FuRIOS: Fieldbus and Remote I/O – a system comparisonWilfried Schmieder und Thomas Tauchnitz, Aventis Pharmaand Sven Seintsch, Infraserv GmbH

Translation of the german article “FuRIOS: Feldbus und Remote I/O – einSystemvergleich”, originally published in atp Automatisierungstechnische Praxis 44 (2002), Edition 12, pages 61-70

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ed into the signal, like when using the HART protocol. Thestandardisation means that many signals are coded in thesame way in all devices, so that they are available in a stan-dard form without requiring any specific decoding for indi-vidual devices. Measurement devices that offer entirely newpossibilities (e.g. simultaneous measurements of differentphysical factors) are in development or already available.Despite these advantages of the fieldbus it has not suc-ceeded in achieving the long-expected market break-through. Although the headlines read “Fieldbus in ProcessEngineering reaches Adulthood” (3) as early as in 1992.Regular reports on successful applications, e.g. (4), theranges of products presented at trade fairs (5, 6) and stud-ies on the economic efficiency of using fieldbus technolo-gy did not lead to the expected success. What reasonscould there be for this delay in market breakthrough, espe-cially in the German process industry? Is it a certain reti-cence when faced with new, as yet untested technology?It appears not, as laboratory tests and smaller pilot plantsconfirm that the fieldbus is ready for use. Are there doubtsthat the fieldbus can provide advantages compared to aRemote I/O system – especially as Remote I/O systemsalready offer the substantial cost cuts compared to con-ventional wiring? Are users unaware of the technologicaledge offered by fieldbus technology, or is it impossible toconvey this message? Or are important components stillmissing for its use?Users and manufacturers have discussed these questions.The project was launched by Aventis, Infraserv andPepperl+Fuchs. IGR (Interessensgemeinschaft RegelwerkeTechnik) provides the platform for a specialist discussionbetween the companies that emerged from Hoechst.During these discussions the idea for the project FuRIOSwas born. FuRIOS is an acronym, meaning “Feldbus undRemote I/O – Systemvergleich” (Fieldbus and Remote I/Osystem comparison) and describes the intention of thisstudy: the two systems should be subjected to a practicalsystem comparison. Not only users have a vested interestin this form of system comparison. Manufacturers of fielddevices and automation systems are also concerned, asthey invested a lot of money over many years in the devel-opment of Remote I/O systems and fieldbus components.Today they are still required to equip each device with theoption for analogue signalling and with interfaces for bothfieldbusses. For how long are manufacturers expected tocontinue with this parallel development of equipment andsystems, which ultimately pushes up the prices? This is thebackground why the following nine manufacturers provid-ed financial support or, in some cases, technical coopera-tion in this project: ABB, Emerson, Endress+Hauser,Camille Bauer, Honeywell, Pepperl+Fuchs, Samson,Siemens and Wika.The following section 2 presents the methodical approachof the FuRIOS project. Section 3 presents the solutiondeveloped for fieldbus; section 4 compares the investmentcosts and section 5 deals with the operative aspects of thefieldbus compared to the Remote I/O. Section 6 provides asummarised assessment of the results of sections 4 and 5.Section 7 then gives an outlook for users and manufactur-ers. The article concludes with a bibliography and an indexof abbreviations.

2. Methodical Approach of the FuRIOS Project

Like with the introduction of all new technologies, theintroduction of fieldbus technology initially requires a com-parison of benefits and costs, whereby the costs must alsoinclude the risk that the new technology may lead to plantstandstill. Accordingly, which methodical approach couldwe use to compare new and existing technology? The cri-teria are:

• Practical approach: a comparison which is intended toassess the suitability for direct use in industrial practicecannot be abstract or theoretical, but must assess theplanned production plant in its entirety.

• On time: the comparison must only take into considera-tion arguments that can take effect in the short-term.Speculation concerning future possibilities confuse theissue and simply make a decision more difficult.

• Completeness: a solution with the new technology mustcompletely satisfy the tasks at hand. Partial solutions thatavoid critical points only lead to false statements.

• Definition: hundreds of general conditions must betaken into account in order to determine the costs andbenefits. These include standard equipment lists, hourrates, tools and procedures in the respective environ-ments. The comparison must be based on absolutelydefinite framework conditions if one wishes to avoidbeing lost in generalities.

In order to meet these criteria, the comparison betweenRemote I/O and fieldbus was carriedout on the basis of a real, newly constructed productionplant for pharmaceutical activesubstances. The comparison solution was drafted on thebasis of the following criteria:

• No changes in the plant requirements: any temptation tofacilitate or obstruct the comparison solution by makingsubsequent changes to the requirements was avoided.

• Greatest possible equality of the solutions, e.g. withregard to availability, especially by using partial redun-dancy.

• Greatest possible equality of the solutions, e.g. withregard to equipped or unequipped reserves.

• Whenever possible, use of the same field devices as inthe real plant, provided they are available with fieldbusinterfaces. Otherwise devices with similar characteristicswere used. Participation of manufacturers in this studyhad no influence on the selection of equipment.

• “Sensible” solution: the criterion for the solution wasthat we would build the plant as planned, in accordancewith our criteria and standards. Therefore, the compari-son solution was not “made feasible” by waiving sensi-ble requirements, but also not “made infeasible” bydefining additional requirements.

• No medium-term dependence on one manufacturer:solutions were not accepted if they could only be pro-vided by one manufacturer in the medium-term. Thechemical-pharmaceutical industry would not accept anysolution of this nature which could therefore not be usedas the basis for any technological decision.

• Availability of the PA devices no later than 10/2002.

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• Conservative calculation: in general “prudent calcula-tions” were used. It is fair to assume that some of theresults will prove to be more in favour of the fieldbus inan a-posteriori analysis than specified in this study.

A comprehensive comparison means that as many other cri-teria as possible that may become relevant over the lifecycle of the plant are taken into account in addition to theinvestment costs. Systematic reasons dictated a clear sepa-ration between the assessment of investment costs (section4) and operational factors.In order to ensure the currency of the comparison equip-ment and connection technologies were required to beavailable immediately. Of course time is in favour of thefieldbus in this respect, as more and more devices withfieldbus interface are coming to market, while the requiredperiphery such as connection technology, field measure-ment technology and software are being developed.

3. Presentation of the Comparison Solution

Used as a reference was a production plant for chemicalsynthesis of pharmaceutical active substances, located inbuilding D712 of Aventis in Frankfurt-Höchst, Germany.This plant was constructed during 2001 and 2002 and wascommissioned in 2002. It is characterized by:• Project costs 13.8 Mio. €, including 3.5 Mio. € costs for

Process I & C• Automated using the process management system

Industrial IT by ABB• Remote I/O: S900 from ABB• Area with explosion risk: zone 1• Pharmaceutical requirements (cGMP)• Planned using the CAE system Comos PT from Innotec

The following quantity framework applies:• 369 Process I&C points connected to Remote I/O (with

821 I/Os)- 155 analogue inputs- 58 analogue outputs- 405 binary inputs- 203 binary outputs

• 62 drives (controlled by means of Profibus DP)

• 2 converters (controlled by means of Profibus DP)

A comparison solution was drafted forthis specific plant, based on fieldbus(figure 1). The Profibus PA was selectedas fieldbus. The main reason for this isthat for this fieldbus currently there aremore devices and tools on the marketwhich meet the european requirementsfor explosion protection.As base concept of the topology the useof fieldbus barriers and valve interfaceboxes has been defined. The power tothe passive fieldbus barriers is suppliedby the bus cable respectively the powerlink module. This connection is

designed in the ignition protection class “increased safety”Ex e, while the designated connections of the field deviceshave the ignition protection class “intrinsically safe” Ex i.Although this deviates from the intrinsically safe design ofsignal transmission preferred in Germany, we believe it isthe most sensible method. The probability that individualfield devices must be replaced is considerably greater thanchanges in the fieldbus segment itself. In that respect theapplication of explosion protection class “intrinsic safety“Ex i is of greater significance. A rough estimate indicatedthat if one does away with the fieldbus barriers and designsthe fieldbus lines to be entirely intrinsically safe, the fieldbussolution would be considerably more expensive than thesolution with Remote I/O. This statement is so importantthat it should be repeated in other words: the fieldbuswould not be economically feasible without the fieldbusbarriers!The use of valve interfaces is also of considerable econom-ic significance. The quantity framework indicates that thereare roughly three times as many binary signals as there areanalogue signals. Bundling of the binary signals in the valveinterfaces significantly reduces the costs. Moreover, some ofthese field appliances could otherwise not be integratedinto the PA bus at all. This, too, would mean that an eco-nomic assessment of the fieldbus would be negative.The planned fieldbus solution is characterised by the fol-lowing figures:• 2 redundant Profibus DP lines for the field devices,• 1 Profibus DP line for drives and converters,• 2 segment couplers (SK2), which – unlike the corre-

sponding Remote I/O solution – cannot be made entirelyredundant through to the respective PA segments,

• 17 Profibus PA segments respectively power link modules,• 64 fieldbus barriers (bus: EEx e, signals EEx i),• max. segment length without spurs 210 m,• max. 17 subscribers to one segment (spurs 15 m each),• the total cycle time of the Profibus PA slaves is less than

364 ms and therefore meets the existing requirements.There was a small number of devices that were not available

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with a fieldbus interface (see below). This requires a “ragcollector” solution. A brief estimate revealed that RemoteI/O solutions would not be economical for these few sig-nals (21 signals). Consequently they were wired directly tothe switch room and there connected to conventional I/Osof the process control system. On top of the additionalhardware costs for a Remote I/O system it also would cre-ate training and commissioning costs, which are omittedhere due to the direct connection to the control system.

4. Comparison of Investment Costs

This section provides a detailed comparison of the effectsof fieldbus installation on the individual components ofthe process control system. In addition to a description ofthe technical characteristics it also contains the economicanalysis.

4.1 Field devices

The technology that has been used until now has necessi-tated equipping the control valves with limit switches. Thedigital positioners report electronically when the limit isreached and transmit this information over the bus.Accordingly, a decision was made to do without the limitswitches. In the comparison plant a solenoid valve waspositioned upstream from the control valves in order toshut down the flow of products completely. A decisionwas made in this study to do without this feature whenusing the fieldbus, as positioners enable a complete sys-tem deactivation which can be monitored by the integrat-ed valve position signalling. However, this does not applyto solenoid valves used for safety critical functions.Satisfactory fieldbus components could not be found forthe following tasks:• Signal lamps integrated in control units require so much

power that they cannot be supplied by the intrinsicallysafe fieldbus. Despite the mainly automatic operation, 5local control units and 2 separate signal lamps were usedin our plant.

• For rotation measurements and current conventionalquantity measurements the signals come in the form ofcounting pulses. There are no fieldbus-compatible inputdevices for these functions, albeit they could conceivablybe binary input signals. The actual plant required a solu-tion for four separate rotation measurements.

• While there are fieldbus-compatible analysis devices forthe major applications available, such as PH and Redoxvalues as well as conductivity and O2 analysis, the analy-sis devices for less frequently used applications such asopacity measurements do not usually come with a field-bus interface. In our case technical safety requirementsdictated the conventional installation of three O2 mea-surements.

• In scaling technology, the signals from the scales cellsmust be processed using an evaluation device. In gener-al, these are not installed in the field, but in the controlroom and can be controlled and actuated per Profibus DP.

As we have already mentioned – and this is also the case

in the existing Remote I/O solution – the 21 specified mea-surements are wired conventionally to the process man-agement system and connected to its conventional I/Ocards. At this point reference should be made to the pro-ject methodology of realising a 1 to 1 solution to thegreatest possible extent. In specific terms, multi-variabledevices were not used (e.g. for flow, temperature andpressure), as these appliances were also not used in theoriginal reference solution and the measurements in theflow and instrumentation diagram would be at differentpoints. Here is additional potential to cut costs if the pos-sibility of using multi-variable devices could be taken intoaccount when drafting the flow and instrumentation dia-gram.The economic assessment of the field devices specified inthis section indicates an additional cost of 4,489 €. Thecost savings for the solenoid valves of 7,400 € are facedwith additional costs of 11,889 € for the field devices withfieldbus interfaces. Therefore, the additional costs add upto 0.6 percent, based on the costs for the field devices of770,000 € for the overall project.

4.2 I/O System

The use of the fieldbus replaces the Remote I/O systemwith all its components entirely. This refers to 20 RemoteI/O systems distributed throughout the plant as well as thecorresponding power supply modules and explosion pro-tection barriers. On the other side we have:

• Additional PLC I/O cards (for the “rag collector” signals)• Components of the fieldbus system (fieldbus barriers,

valve interface boxes, segment couplers, power linkmodules)

• An additional process-near component was also requiredfor the process control system in use, as the componentsoffered by that specific DCS manufacturer offered onlyfour Profibus DP connections, but five were needed. Thecorresponding additional costs are specifically linked tothis DCS manufacturer, as other systems have more andsometimes less than four fieldbus connections perprocess-near component. If we had done a more plant-specific allocation of the functions to several process-near components this additional cost would not haveoccurred. Therefore the PA solution would have beeneven more cheaper.

The economic assessment of the I/O systems described inthis section leads to cost savings of 76,212 €. The costsavings of 138,562 € for the unnecessary Remote I/O sys-tem are faced with additional costs of 46,350 € for allfieldbus components as well as 16,000 € for an additionalprocess-near component. The cost savings amount to 18.1percent, based on the costs for the I/O system of 420,000 €.

4.3 Engineering of the Field Technology

The Remote I/O systems that have been used until nowrequire a significant level of engineering costs; in addition,the considerable space they required necessitated specific

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consideration in the location planning. The decentral I/Ocabinets had to be positioned throughout the plant andequipped with I/O cards in an optimal way. Therefore onehas to define in advance which devices will be connectedto which cabinet. Very often this is an iterative procedure.Detailed plans with corresponding documentation werenecessary for the Remote I/O. Some I/O systems require aspecial calculation of the heat dissipation in order to com-ply with the requirements of explosion protection. Theintrinsic safety has to be confirmed for each specific com-bination of field device and Remote I/O card.When using fieldbus technology many of these activitiesare not necessary while others are considerably simplified.The topology of the fieldbus is rather simple with just afew, compact components inside the plant, thereforerequiring considerably less planning. Due to the free com-bination of devices connected to a fieldbus segment amore precise allocation in the plant can be achieved com-pared to Remote I/O, without any additional expense.Thanks to FISCO the confirmation of intrinsic safety is con-siderably easier.The used planning tool has a significant influence on thecosts relating to the plant documentation. If a databasedCAE tool is used, like Aventis uses the Innotec tool “ComosPT”, the documentation costs are low – for both theRemote I/O and the fieldbus. However, the cost savingsthat can be achieved with fieldbus are firstly due to thefewer connections, such as with the valve positioner, andsecondly due to the fact that the PA connection is identicalat all devices. This means that the otherwise necessarytransfer of device and manufacturer-specific graphic sym-bols and connections to the standard library of the CAEtool is no longer necessary.The economic assessment of the fieldbus technology engi-neering described in this section indicates to cost savings of9,076 €. The main items are the obsolete I/O allocationplanning, the simplified confirmation of intrinsic safety andthe simplified creation of typicals in the CAE system. Thesesavings reflect 3.2 % of the total costs of engineering inthe project, amounting to 280,000 €. The cost savingswould have been considerably greater if the plans had notbeen created with the CAE system, but rather – like Aventisdid until two years ago – with a relatively high cost formanual labour. Estimates indicated that the fieldbus costsavings would then have been 33,188 € or 11.9 % of theengineering costs.

4.4 Engineering of the DCS

At first glance it may appear surprising that the choicebetween Remote I/O and fieldbus influences the DCS engi-neering. Nonetheless, this influence is really quite signifi-cant for the overall result. This is ultimately due to the factthat the level of fieldbus standardisation is rather high –unlike with Remote I/O. When using Remote I/O separateprogramming respectively evaluation is necessary for each

device to define the significance of each code pattern ofthe status bytes. Fieldbus status information is coded in astandardised manner so that device-specific configuration,implementation and analysis of typicals are not necessary.This allows configuration in the DCS independent of themeasuring devices and to a certain extent independent ofthe measured factors, too.Another difference becomes obvious when planning theDCS: Remote I/O connects the field devices via an interfaceas “external systems”, whereas with fieldbus the commu-nication with the devices is transparent, as if they wereconnected directly to the DCS. This facilitates engineering,commissioning and testing.The economic evaluation of the DCS engineering describedin this section indicates cost savings of 24,795 €. Thisamounts to 4.7 %, based on the total costs of engineering;it accounts for almost twice as much, based on DCS engi-neering alone.

4.5 Installation

By changing from conventional wiring to Remote I/O thegreatest potential for savings on installation costs hasalready been realized. Former conventional plant commu-nications had required local distributors, multicore cablesand patch cabinets. Later Remote I/O systems wereinstalled directly in the field, the only individual connectionswere between field device and Remote I/O. From the latterto the control room a bus cable was used. All that wasrequired in addition to the bus cable was an auxiliary powersupply to the Remote I/O station. Considerable cost savingshave been achieved in wiring, in the cable tracks and interms of space in the control room. But this was not a topicof this study.Now costs can be even more reduced by changing fromRemote I/O to fieldbus. In general, the cable lengths for thespurs are shorter, since the fieldbus barriers are moredecentralized located than the Remote I/O stations due totheir greater number. The installation of the extremelysmall and light fieldbus barriers forms no problem, where-as the large Remote I/O stations must be assembled verycarefully. Wiring of the I/O stations with auxiliary powersupply is also no longer necessary. Due to the larger num-ber of fieldbus segments and the “rag collector” signalsthe number of cables to be laid between the field and thecontrol room remains approximately the same. The eco-nomic assessment of the installation described in this sec-tion leads to savings of 10,732 €. These are 1.5 percent,based on the costs of Process I&C of 700,000 €. Althoughthis is not very much, it must be seen in the context withthe high savings that were achieved already by replacingconventional wiring with Remote I/O.

4.6 Calibration and Qualification

In general, the type of connection technology has no influ-ence on the calibration of the equipment and the costs thisaccrues. However, the situation is very different with regardto the calibration and qualification the process control

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sification of the measurement valuesand therefore does not have to be cal-ibrated, the conventional analoguesignal path is subject to faults, thusgenerating calibration, qualificationand documentation costs. Further-more the setting and validation of themeasurement range is no longer nec-essary; only a plausibility test isrequired for the qualification.The economic assessment of the cali-bration and qualification described inthis section leads to savings of 5,967 €.This amounts to savings of 4.3%,based on the total costs of calibrationand qualification of 140,000 € for thewhole project.

4.7 Commissioning

As already mentioned on several occasions, the integrationof the field devices into the overall process control systemworks considerably better with the fieldbus than with theRemote I/O. The reduction of error sources, the use of stan-dards and the easier fault diagnosis due to the greatertransparency mean that commissioning is much faster.Testing of the entire, readily installed Process I&C point, theso-called loop check, is no longer necessary. It has only tobe checked whether the correct device is connected andwhether it emits a “sign of life”. The economic assessmentof the savings relating to the commissioning described inthis section amounts to 2,400 €, based on half an hour sav-ings per analogue device. This amounts to 2.3 %, based ona total cost of commissioning of 105,000 €.

4.8 Summary of the results

Table 1 provides a summary of the additional costs respec-tively savings specified in the above chapters. In total, thesavings in terms of Process I&C investment costs amount toapprox. 125,000 €, or 3.6 % of the total Process I&C costs.The table also indicates that some parts of the project arenot affected by the communication technology, for examplethe electrical engineering, the analysis appliances and theproject realization itself. If one deducts these areas, the totalsavings amount to 4.2 % of the relevant Process I&C costs.Reference should be made once more to the influence of theused CAE tool on the savings in engineering, as indicatedabove in section 4c. Without this influence, the savingswould amount to 4.2 percent of the total Process I&C costsor 5.0 percent of the relevant Process I&C costs.

5. Comparison of Operational Factors

The previous chapters dealt with the effects of the fieldbuson the investment costs. We were dealing with “hardfacts” that could be calculated precisely. The following sec-

tion describes the other effects and evaluates them to thegreatest possible extent. Firstly, this relates to the effects onthe life cycle of the plant which cannot be defined as pre-cisely as the investment costs. Secondly, it also relates tothe indirect effects, which are manifest, for example, inhigher production rates of the plant and therefore in ben-efits outside of the Process I&C area. Because these factorsare always dependent on the type of production and mar-ket situations, the actual benefits cannot be estimated in ageneral sense. Readers are encouraged to determine theeffects in their industries and production plants themselves.

5.1 Influence on the project running time

Section 4.7 has already made reference to the considerableeffects on commissioning. Whereas that section dealt withthe direct savings in investment costs over the course of theproject, this section discusses the influence on the projectrunning time.Our calculations revealed that – if there are realistic teamsizes – four days could be saved during installation, fivedays during qualification and two days in commissioning.This may not appear sensational at first glance if one con-siders the 12-18 months that are usually estimated for sucha project. However, upon detailed analysis of the projectplans one can see that the installation, the qualificationand the commissioning of the Process I&C are always timecritical areas. Put in colloquial terms: the Process I&C peo-ple are always the last in and have to be the first out. So itis fair to say that the use of fieldbus can speed up the over-all project by about 10 days!Any attempt to estimate these savings in Euros and Centsis doomed to failure. The benefit depends on whetherthese two weeks can be turned into earlier market pres-ence, a bigger market share or an increase in turnover orwhether they are wasted somewhere else in the project, inproduction or in marketing. In general, however, the pres-sure to meet tight project deadlines is growing from year toyear, so any acceleration in project finalization is of consid-erable value. In order to estimate this value, readers are rec-

Table 1: Influence on investment costs (all prices in € ).

Costs RIO Price changes Costs PA: Min. (%)

Electrical.: 0% 140,000 0 140,000 0,0 %

Analysis devices.: 0% 140,000 0 140,000 0,0 %

Project handling: 0% 280,000 0 280,000 0,0 %

Field devices: +0,6% 770,000 4,489 774,489 0,6 %

I/O-System: –18,1 % 420,000 –76212 343,788 –18,1 %

DCS incl. Engineering.: – 4,7 % 525,000 – 24,795 500,205 – 4,7 %

Installation: –1,5 % 700,000 –10,732 689,268 –1,5 %

Calibr./Quality: – 4,3 % 140,000 – 5,976 134,024 – 4,3 %

IBS: – 2,3 % 105,000 – 2,400 102,600 – 2,3 %

Engin.: – 3,2 % 280,000 – 9,076 270,924 – 3,2 %

Total all Process I&C 3,500,000 –124702 3,375,298 –3,6 %

Total relevant Process I&C 2,940,000 – 124,702 2,815,298 – 4,2 %

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ommended to calculate the turnover of a new product intwo weeks, based on the annual turnover, and the corre-sponding profit margin in their respective markets – theproject acceleration could create considerably more valuethan the entire savings in investments!

5.2 Influence on the training of technical staff

In general, Remote I/O as well as fieldbus requires trained,well-qualified process control specialists. We estimate thattechnicians require two days of training on fieldbus tech-nology in order to learn installation, diagnosis and faultrepair. The same amount of time would be needed fortraining on Remote I/O. However, the manufacturer specif-ic Remote I/O variants require specific training for deci-phering the codes. Due to the standardized protocol this isnot necessary with fieldbus. These savings are estimated tobe 2.5 days of training per technician. In case of three tech-nicians within the plant we estimate the savings on trainingto be about 4,000 €.This is a remarkable result since it contradicts the generalassumption that a new technology is always more complexthan the old, replaced technology and therefore traininglevels are continually rising. This result is due to the stan-dardisation of fieldbus which avoids special training as wellas to the increase of transparency and constancy thanks tofieldbus technology. The system now works fully digital,thus gaining the advantages of this homogenity.

5.3 Influence on quality

Due to fieldbus two signal conversions are omitted: oftenthe measurement signal is generated digitally and thenconverted to an analogue output signal, which then is re-converted to digital in the process control system – and viceversa for actuators. Two systematic sources of errors areremoved with the disappearance of these signal conver-sions. Fault reproduction no longer needs to be consideredand the entire signal loop is exactly as accurate as the sen-sor or actuator itself. Ultimately the measurement toler-ances are significantly smaller. This could either be used formore precise measurements or settings with the same fielddevices or to achieve the same total tolerance with devicesof lower tolerance quality. Especially the latter couldbecome economically significant in cases where up to nowthe required tolerances could only be reached by specialand therefore expensive precision measuring equipment. Ageneral statement on the economic benefit cannot begiven here – but it could be very significant.Two more factors influence the total quality of the processcontrol system: Many chances for errors are avoided direct-ly at the source, e.g. if the alias values have not to be attrib-uted individually any more. Errors which cannot occur at allcannot lead to losses in quality.Furthermore – and this is second factor – error detectionand correction is much faster due to the transparency offieldbus. Therefore the resulting damage is considerablyless. An economical assessment of these factors is not pos-sible at the moment, too.

5.4 Influence on fault correction

The fieldbus increases the transparency of the system.Therefore fault detection is much faster or, even better,faults are reported actively. Fieldbus technology allows theuse of “intelligent” devices featuring superb self-diagnosis,even up to signalling the need for preventive maintenance.On top of the faster fault detection the increased reliabilityof error diagnosis will have a positive influence, too. If thedevices run a reliable self-diagnosis and send an “ok”-sig-nal they need not to be removed, tested and re-installed onsuspicion.The calculated direct economic benefit of this simplifiederror handling is disappointingly low. We estimate about500 € a year. This is due to the low failure rate of thenowaday’s technology – we estimate it at 0.5 % per year.This again is a direct success of the rather conservativehabit of commissioning new devices only after extensivetesting in the laboratories of NAMUR member companiesor after solid operation experience.The indirect benefit is several times bigger but cannot becalculated universally. However, if fieldbus technology helpsto avoid faulty batches or the loss of just one day of pro-duction, this benefit may amount to several 100,000 €.

5.5 Influence on maintenance and inspection

Section 5.3 describes how possible error sources in signalconversion and transmission are avoided due to fieldbus.Therefore the calibration of the production line during theannual testing is not necessary any more. This annual test-ing is mandatory, at least in pharmaceutical productionenvironments. In the reference plant this applies to 25 cal-ibrations, adding up to savings of 2,500 € p.a. Furthermoreit allows to omit the calibration of an installed device bysimply replacing it by a readily calibrated one. This speedsup the annual tests and shortens the period of productioninterruption, which has a significant economic value.Another topic cannot be clarified definitively. It is possiblethat the calibration cycles of the sensors can be increasedsignificantly – even beyond the current minimum of onceper year.This results from the fact that very often the sensors have ahigher long-term stability than the signal conversion elec-tronics in the analogous devices. Since the signal conver-sion is omitted the calibration cycle could be adjusted tothe long-term stability of the sensor. Once this will beaccepted by the quality departments and control boards –surely only after extensive practical experience – even moresavings are possible. In terms of the Process I&C of the ref-erence plant this would mean 7,500 €, the operationalbenefit due to reduced downtimes cannot be estimated.

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6. Assessment of the Results

6.1 Assessment of the investment costs

The above presented savings in the Process I&C costswhich amount to 3.6 through 5 percent, depending on theperception, may seem disappointing at first glance. Thevalues of about 20 percent which former studies indicatedled people to expect more. However, it is to be recalledthat these studies (8) determined the potential savingsrelating to fieldbus technology in comparison with con-ventional wiring. Roughly it can be said that Remote I/Osaves about 15 % over conventional wiring and fieldbustechnology saves an additional 5 %.Taken realistically, greater savings in investment costs couldnot really be expected by changes of the communicationtechnology alone, as the number of cables laid betweenthe control room and the field remains approximately thesame. However, these savings are relevant: it is a consider-able leap if the introduction of a new technology leads toa 5 percent drop in investment costs for a certain field –even without the discovered additional benefits during thelife cycle. Which other technology leap over the last fewyears has generated savings of 5 % off overall costs inother fields such as construction engineering or apparatusengineering?

6.2 Assessment of the operational factors

Besides some relatively small factors, like training or costsof Process I&C maintenance, there are major changes inthe operational factors: if plants can be put into operationfaster thanks to fieldbus technology, if they have lessdowntime during malfunctions or can be run with greaterprecision, then this is the major benefit of fieldbus tech-nology. One day of production profits in a plant operatingat maximum capacity can easily generate 500,000 €. Orvice versa, one day of downtime can destroy the sameamount. Unfortunately the benefit potentials cannot bedetermined universally since the influences of plant loadlevels, market situations and profit margins are far too big.However, the benefits in operation surpass the savings ininvestment costs by far. From our perspective it is a pleas-ant bonus that these benefits in operation – unlike as withmost other innovations – must not be paid for by higherinvestment costs, but are accompanied by additional sav-ings, even if they are relatively small.

6.3 Assessment of the methodology

An assessment of results would be incomplete without anassessment of the methodology. The methodologydescribed and substantiated above led to a conclusive,comprehensible assessment within a relatively short periodof time. Of course it cannot yet be concluded with an eval-uation of a real project, since the decision for future plantdesigns with fieldbus will be based on this study. It has tobe noted explicitly that there is a certain risk to find somediffering results in a real practical comparison.

In a methodical sense the approach of drafting a compar-ison on the basis of a real, operational plant is highly indanger of subjective errors. The selection of plant location,size, type and equipment leads to specifications that can-not be generalized. Furthermore, the point in time of thisstudy could have a significant influence, too. The resultsmay be different in six months from now. Accordingly, oneshould be careful in transferring the results to other plantsor in assuming that the results are generally valid. Theremay indeed be plant sizes for which the Remote I/O solu-tion is the best. The evaluation of continuous processeswith respective availability requirements may lead to dif-ferent assessments. With revamps of existing plantsRemote I/O allows to continue using the installed fielddevices. On the other hand, for example, fieldbus technol-ogy would be even more beneficial to larger, more spreadout plants than our reference plant. Specialists around theworld should feel invited to apply the methods of thisstudy to other plant types and to communicate the resultsso that more general statements will be possible.Another uncertain area of the FuRIOS project is that thecomparison was carried out on the basis of Profibus PAand not Foundation Fieldbus. Without having consideredthe details of a solution with FF, we would venture theopinion that the results of a study with FoundationFieldbus technology would be similar. Advantages and dis-advantages of the different fieldbusses would be apparenthere and there, but this would not affect the result by any-thing more significant than 10 %.One more critical statement about the FuRIOS project isnecessary: This study was carried out to the best knowl-edge of the authors, using their experience with fieldbustest systems. However, there is a lack of practical experi-ence. Some assumptions may be overly cautious; problemsmay occur in the implementation of a real project whichhave been overlooked here. Most certainly there are“teething problems” to be expected in the first projects,which could eat away the estimated savings. Faster com-missioning is also unlikely to be possible in the first project.

7. Outlook

The methodology of this project was the 1 to 1 reflectionof a real plant realized with Remote I/O to a plant usingfieldbus. Used cleverly, the fieldbus technology will lead tofurther cost savings and increased benefits. On one handthe user is asked to be flexible in his thinking while on theother hand the manufacturers face new requirements.

7.1 Outlook for users

The fieldbus technology is the technological platform forfurther development of the field devices. Already the firstproducts are available: So-called multi-variable devices canmeasure several physical factors at the same time, forexample flow rate, pressure and temperature. Devices ofthis kind are inexpensive and – thanks to fieldbus – can beconnected just as easily as single value devices. In FuRIOS

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it was not possible to use them anywhere since tempera-ture and pressure measurements were never taken at thesame pipe or at the same installation point. The users arerequested to become aware of the possibilities of multi-variable devices and to take them into account when draft-ing the flow and instrumentation diagram.Fieldbus is the technological basis for new device develop-ments. A rod probe that measures a temperature profile, avalve that counts how often the valve opens, an analysisdevice monitoring itself – only fieldbus allows a sensibleand efficient integration of all this into process automation.This insight was published years ago: “Fieldbus technologyas the driving force behind automation engineering” wasthe name of an article back in 1999 (9). The common termat the moment is enabling technology, which means thesame thing. Fieldbus represents an innovative technologicalplatform – manufacturers and users have to decide whichdevices will use this platform and how they will be utilized.Fieldbus is also the fitting technological basis for asset man-agement systems. Until now, these systems have requiredseparate bus systems for transmitting the device informa-tion. This is no longer necessary since fieldbus transportsthese informations. This may (finally) help asset manage-ment systems to achieve the breakthrough that has nothappened until now. However, the discussion on how thetasks should be optimally distributed between CAE system,asset management system and ERP system is not over yet.The cost/benefit analysis of asset management systems hasbeen consciously left out of this study, it has to be discussedat some later date.

7.2 Outlook for manufacturers

Not only users are encouraged to make more intelligent useof fieldbus than simply replicating current tasks 1 to 1.Manufacturers are also called on for further developments,in particular to pursue the following ideas:• Feeder devices (power modules) with a higher supply cur-

rent (considerably more than 400 mA) would be sensible,as many appliances – sometimes with good reason –require considerably more than 10 mA. A higher supplycurrent would not only reduce the number of fieldbuslines, it would also enable more and more devices tochange from four-wire supply to two-wire supply.

• A valve interface box for Profibus PA with bus connectionin increased safety Ex e would allow the control of morepowerful intrinsically safe solenoid valves (this is alreadyavailable for Foundation Fieldbus).

• A “mini Remote I/O” for the Profibus PA, also with busconnection in increased safety Ex e, would make conven-tional wiring (for frequency inputs, too) or a separateRemote I/O as “rag collector” superfluous (at themoment, the only available solutions use auxiliary power).

• The address scope of 126 addresses with Profibus DP is alimiting factor. The standardisation committees shouldattempt to achieve a revision of this limit.

• A process-near component should not be limited to tworedundant Profibus DP lines only. This increases the num-ber of components unnecessarily. However, many systemsalready satisfy this wish.

• Software tools for calculating the manufacturer specificconnections are required. At the moment, not all manu-facturers of fieldbus components offer them.

• A simple bus monitor system for Profibus PA for diagno-sis at the Ex segment would be sensible. The FF alreadyoffers it.

• At the moment, Profibus PA does not have the option ofcontinuous redundancy, at least up to the respective PAsegment.

Manfred Dietz, Infraserv Hoechst, Harald Hauch and Josef Will, Aventis, cooperat-ed on the project in addition to the named authors. Staff from the manufacturersinvolved also cooperated, and our thanks goes out to them at this point.

Bibliography:(1) Gangbarer Weg – Remote I/O-Systeme in der Prozessautomation.

Chemie Technik, 28 (1999), Nr. 4, S. 38–40.

(2) Klemm, E.: Internationale Feldbusnorm IEC61158 ist Realität.etz, Heft 6/2000

(3) Hils, F., Lindner, K.-P.: PROFIBUS – Der Feldbus für die Verfahrenstech-nik wird erwachsen. atp – Automatisierungstechnische Praxis 34(1992), H. 12, S. 661–667.

(4) N.N.: Zielsichere Vorlage. Chemie Produktion, H. 3/1998, S. 44–47.

(5) Rathje, J.: Der Feldbus in der Verfahrenstechnik. atp – Automatisie-rungstechnische Praxis 35 (1993), H. 2, S. 135–137.

(6) Rathje, J.: ACHEMA 97: Der Feldbus kommt ins Rollen – Ein Situations-bericht. atp – Automatisierungstechnische Praxis 39 (1997), H. 10, S. 56-59

(7) Max, G., Heidel, R., Frehse, K. P.: Wirtschaftlichkeit des Feldbuseinsatzes.atp – Automatisierungstechnische Praxis 34 (1992), H. 9, S. 507–512.

(8) Rathje, J.: Braucht die chemische Industrie den Feldbus? atp – Auto-matisierungstechnische Praxis 36 (1994), H. 4, S. 22–30.

(9) Neumann, P.: Die Feldbustechnik als Motor der Automatisierungs-technik. atp – Automatisierungstechnische Praxis 41 (1999), H. 7, S. 27-34

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Abbreviations:CAE: Computer Aided EngineeringDCS: Distributed Control SystemFuRIOS: Fieldbus and Remote I/O system comparisonProcess I&C: Process Intstrumentation and ControlFISCO: Fieldbus Intrinsically Save ConceptPLC: Programable Logic ControlerProfibus DP: Decentral Periphery (see IEC 61158)Profibus PA: Process Automation (see IEC 61158)

Dipl.-Ing. Wilfried Schmieder is head of the ProjectProcess Control Technology team within the Technical Engineering Active Substances Department at Aventis Pharma Deutschland GmbH.Address: Aventis Pharma Deutschland GmbH, ITW.DS581, D-65926 Frankfurt/Main, phone (069) 3 05-121 22, fax -31 10 46, e-mail: Wilfried.Schmieder@aventis.com

Dr.-Ing. Thomas Tauchnitz is head of the Technologyand Projects group within the Technical EngineeringActive Substances Department at Aventis PharmaDeutschland GmbH. Within NAMUR, he is coordinatorfor working field 2 Integrated Solutions and Systems.He heads the working field Management Technologywithin IGR (Interessengemeinschaft RegelwerkeTechnik).Address: Aventis Pharma Deutschland GmbH, ITW,D610, D-65926 Frankfurt/Main, phone (069) 3 05-41 94, fax -8 30 98, e-mail: Thomas.Tauchnitz@aventis.com

Dipl.-Ing. Sven Seintsch is head of analyses on variousfieldbus test installations within the test laboratory ofInfraserv GmbH & Co Höchst KG. He is member of theNAMUR working group 2.6 Fieldbus. He is also head ofthe working group Fieldbus within IGR(Interessengemeinschaft Regelwerke Technik).Address: Infraserv GmbH & Co Höchst KG, MSR-Technik, Prüflabor, D710,D-65926 Frankfurt/Main, phone (069) 3 05-1 32 60,fax: -1 59 78, e-mail: Sven.Seintsch@Infraserv.com

FuRIOS Fieldbus and Remote I/O System Comparison

Push-button telephones were the first step on the way to the mobile phoneNew technological platforms in the field of automation technology can only be achieved with the fieldbus

Dr. Eckert: FuRIOS compares the costs of a real,working plant equipped with Remote I/O sys-tems with those of a calculated one-to-one refer-ence solution based on the fieldbus technology.How does that work?

Dr. Tauchnitz: Well, it’s basically a thoughtexperiment. We take a reference plant – one thatis so new that it would be equipped in exactly thesame way again – and we ask the question: Howwould it have looked like if it had been based onthe fieldbus? It’s a very simple concept.Discussing the benefits and disadvantages offieldbus on the basis of virtual solutions is toocomplex and abstract. Other companies haveother methods, they structure their plants differ-ently. We tailored our approach to our plants. Theother users should now look at the calculationsfor their plants. I think the comparison of theresults could be very interesting.

M. Dietz: There would always have been doubts as towhether our assumptions were realistic. Now the userscan say: "Our plants are different" if they want, butthey cannot go past the fact that a real plant has beeninvestigated.

Dr. Eckert: What were the criteria for choosingthe components for the calculation?

M. Dietz: We had an unrestricted choice of the field-bus components. It must be said, however, that thePepperl+Fuchs FieldBarrier is currently the only field-bus barrier we accept, as it is the only one with therequired galvanical isolation. In the case of the cou-plers, the control system was the decisive factor. Thesame control system will be installed in the new plantas is in the reference plant. Of course, with a one-to-

one solution, nothing can be changed here. The use ofthe ABB control system inevitably leads to the use ofPepperl+Fuchs couplers. They are not in the programmerely because Pepperl+Fuchs were the instigators ofFuRIOS. It would quite simply have cost us our credi-bility if we had chosen couplers from someone else.

Dr. Eckert: Why are the segment couplers, valvecoupler boxes and fieldbus barriers so crucial forthe economic feasibility?

Dr. Tauchnitz: They make it possible to connect alarger number of devices to a PROFIBUS PA line.This saves on installation and cabling costs. If weassume that 500 signals have to be collected andeach PA line can deal with only six or seven sig-nals, 80 segment couplers would have to be usedand 80 cables have to be led? from the non-exarea to the hazardous area. This costs twice asmuch as 40 segment couplers and 40 cables. If wehad had such a small number of signals per PAline and needed that many cables for it, it wouldquite simply have been more expensive than theRemote I/O.

M. Dietz: In other words, connecting seven devices toone line means only one seventh of the cables are need-ed. Just imagine the fieldbus as a kind of high-techwashing line – you hang your shirts and trousers on itand save yourself a lot of work compared to if you hadto drive new posts into the ground and stretch outnew washing lines for each garment individually. Ithalves the expenditure for installation and compo-nents. A doubling to up to 30 devices is possible oncethe energy supply problem is solved. With 2 amperesof supply current we could have hung a lot morewashing out to dry – to stay with that metaphor. Atthat time we didn't have a 2 ampere coupler available.

The results of the fieldbus and Remote I/O system comparison FuRIOS caused quite a stir at the NAMURgeneral assembly beginning of November 2002 and triggered off renewed discussions between manufacturersand users about the application of the fieldbus technology. Over the last few months several enterprises havedecided to start with fieldbus projects. FuRIOS could prove to be the breeze that fans the further developmentof the fieldbus. The journalist Dr. Christine Eckert spoke about this with two of the initiators of the FuRIOS study:Manfred Dietz from Infraserv Höchst and Dr. Thomas Tauchnitz from Aventis Pharma Germany.

FuRIOS Fieldbus and Remote I/O System Comparison

However, we currently have one under test. FuRIOShas shown that fieldbus barriers with more supplycurrent are needed. If we had started the project a yearearlier, the result would have been clearly in favour ofthe Remote I/O systems. I am absolutely convinced ofthat. As it turned out, this was just the right point intime, although we didn't know that beforehand. Withevery year that passes, the result will be more andmore in favour of the fieldbus.

Dr. Eckert: What speaks for the fieldbus technol-ogy and what additional possibilities does thenew technology open up?

Dr. Tauchnitz: With regard to the required invest-ment, the result is quite sobering. Saving fourpercent on the investment costs is not chickenfeed, but it’s not the world either. A cost calcula-tion without couplers, fieldbus barriers and valvecoupler boxes would presumably have been fourpercent more expensive. Then we would havehad to base our argumentation on the life-cyclecosts alone. The way it turns out now, it is muchsimpler. Both the investment costs and the life-cycle costs can be named as benefits. In the inter-nal discussions those four percent are definitelyan issue.

M. Dietz: FuRIOS compares fieldbus and Remote I/Owith the same equipment functionality. Today I alwaysend up with the same measurement, regardless ofwhether the pressure transmitter is connected to thefieldbus or to the Remote I/O. In five years from nowthe discussions will be completely different. The addi-tional opportunities provided by the fieldbus technolo-gy couldn't even be considered in this comparison ofthe two systems. At this moment the difference is min-imal, but that will change. Those who have fieldbuswill be prepared for a world of innovative measure-ment technology. Those with Remote I/O systems willonly be able to look back to the past. There is nothingnew coming to keep Remote I/O up to date.

Dr. Tauchnitz: Mr. Rathje from Bayer, a memberof NAMUR, once said: “When we have fieldbus,we will save 40 % of our costs”. I like to use theanalogy of a mountain. Remote I/O takes usaround 90 percent up the mountain. That meansaround 36 percent of savings. Many people nowsay: It isn’t worth changing the technology just to

get that little bit closer to the summit – the lastfour percent. But what they are forgetting is thatthe mountain is a volcano. It is growing all thetime. New technologies are becoming availablethat don’t work without the fieldbus. For exam-ple the famous thermometer probe. It measuresthe temperature at ten places in the boiler. Thatsimply isn’t possible with 4 to 20 mA. You canonly make full use of the growth of this mountainand the benefits of the technology if you climbthat last little bit as well. Technologically speak-ing the Remote I/O was not an innovation. Whatremained was the same mountain and an ana-logue signal.

Dr. Eckert: What benefits do modern fielddevices have and what might the device of thefuture be like?

M. Dietz: A field device connected to Remote I/O isan appendage tagged onto the system, and you have tosee how you can gain access to the parameters. A fielddevice on a fieldbus is an integral part of the system.That alone just about says it all. With Remote I/O sys-tems you isolate yourself from this development. Thefield device of the future will be multi-functional andwill make asset data accessible. Even if we only wantto mention diagnosis briefly – we can expect all sortsof things to happen there. All the companies that cur-rently speak of diagnosis on the field devices have justdeveloped the kilometre counter. If I take my car to thegarage nowadays, they stick a diagnosis plug into itand it tells me what I did wrong, what is broken andwhat maintenance means. The basis for all this wasthe kilometre counter, and in the field of diagnosistools we have only just reached this level. What can beexpected from future diagnosis alone already justifiesthe fieldbus. Diagnosis means: I ask the appliance if itwill require servicing already at the next plant stand-still in four weeks or whether it can wait till the fol-lowing standstill in thirteen months time. This is theway towards predictive maintenance and can only berealized with the fieldbus technology.Dr. Tauchnitz: Only the fieldbus technology cankeep up with the growth of the mentioned vol-cano. The devices that will be on the market inten years time will have possibilities that cannotbe utilized with 4 to 20 mA. Dr. Kegel fromPepperl+Fuchs once compared this to the devel-

FuRIOS Fieldbus and Remote I/O System Comparison

opment of the telephone: “At some stage the dialhad to be replaced by buttons. It didn’t have anysignificant benefits at the beginning, but mobiletelephones would never have been possible with-out push-buttons. Today we can do our bankingwith the cellular phone or send pictures all overthe world at the touch of a key. So the step fromthe dial to the button was essential. And this isexactly the same step we have to take today, oth-erwise we won’t be able to make the technologi-cal transition to a new platform.

Dr. Eckert: The industry park Höchst is a pioneerin this field. What problems do you anticipatewhen building the first plant?

Dr. Tauchnitz: With Remote I/O systems wealready have the PROFIBUS DP interface in oper-ation. Instead of Remote I/O a fieldbus isolatorwill now be used and the fieldbus barriers andvalve coupler boxes lie beneath them. If thereever will be a communication disturbancebetween the process control system and one ofthe field devices, that device and only that onewill have a problem. I don’t see any risk that ourcomplete plant could be brought to a standstill. Itis still the same PROFIBUS DP as is being usedwith the Remote I/Os, and it has proven itselfthere.

M. Dietz: The team at Infraserv Höchst will test thecommunication of the entire system in advance andwill support the project team throughout the entirecompletion time. The key to success is the timelytraining of planners, plant administrators and man-agement staff. It would be very counter-productive ifthe staff suddenly had to go to a training course justwhen the commissioning of the plant is entering thecritical phase. I hope that we will be able to start thetraining courses for the PROFIBUS PA at the begin-ning of March latest.

Dr. Eckert: Won’t the other users wait until allthe start-up difficulties have been done awaywith?

Dr. Tauchnitz: There are no signs that the othercompanies intend to sit back comfortably andwatch for a year and a half until our plant is fin-ished. In those eighteen months they wouldacquire new equipment that is based on a tech-

nology that won’t support new appliances in fiveyears time. Engineers don’t like to gather oldmaterial that costs, and then has to be disposedof. Using a new technology holds the same riskthan sticking too long to an old one. We are con-vinced that the project will be a success, other-wise we wouldn't be doing it.

M. Dietz: All plants are unique. As long as there isnew equipment being launched onto the market therewill be start-up difficulties. This is true of all devices,be they fieldbus or not. We calculated everything inFuRIOS. Even more, the testing laboratory atInfraserv Höchst is at our disposal at all times, withits manpower and specialist know-how. If any suspi-cion should ever arise that something doesn’t workproperly, every manufacturer involved will do every-thing in his power to solve the problem. Do you thinka project fails because one manufacturer doesn't dowhat is required of him? Perhaps the follow-up pro-jects will be a little less expensive, but never before hasa technology been as perfect before its market launchas the fieldbus is now. We are convinced that it willwork. If we weren't, how could we possibly expect others to be?

The new plant for pharmaceutical agents pro-duces several stages of the new antibiotic Ketekfor treatment of acute respiratory infections. Theinstrumentation of the plant is based completelyon fieldbus technology, which makes it one of themost modern of its kind. The only exceptions arethe safety oriented applications and a fewremaining conventional signals. The cost for theProcess C&I are about 12 million Euro. The plantis divided in 200 Profibus PA segments with atotal of 1.600 Profibus PA field devices. Two pro-duction lines comprise 15 device types of sevendifferent manufacturers, all of them working fullyinteroperable. The control system is supplied byABB. The complete fieldbus installation fordevice connections in explosion hazardous areasfollows the fieldbus barrier concept and is real-ized by means of the FieldConnex system ofPepperl+Fuchs.„Ketek is one of the largest projects of our projectteam. In some areas of engineering and construc-tion we have been supported by Siemens“, says

Bodo Bartscheit, project manager Process C&I atAventis. Not without some pride, since the com-plete project was under the full responsibility ofthe team. In order to optimize the coordinationwith the engineering company his colleagueHarald Hauch, project manager automation,acted as interface between plant operator and ser-vice companies. For the creation of commission-ing and installation procedures as well astraining of personnel Aventis took the specialistsof Infraserv Höchst Technik on board, thus takingadvantage of the experienced team which hadalready been involved in conducting the FuRIOSstudy.FuRIOS is a classical evaluation which took a realplant, working on Remote I/O technology, andprojected it 1:1 to fieldbus technology – withabsolutely identical requirements. With the Ketekproject Aventis followed these prerequisites anddesigned topology and instrumentation accor-dingly. “Maybe we designed 1:1.01 on fieldbus.But in general the design work went as usual“,

From theory to practical operationAventis builds pharmaceutical production plant based on FuRIOS Study

Two years ago Aventis Pharma Deutschland and Infraserv Höchst Technik conducted the FuRIOS study(Fieldbus and Remote I/O System Comparison) in order to evaluate the cost/benefit aspects of fieldbus tech-nology and to increase its acceptance in the process industry. This system comparison convinced the producerof pharmaceuticals and soon after publication of the study Aventis started to turn these theoretical considera-tions into real practice. The Ketek plant is the first automated production plant which follows therecommendations of FuRIOS.

FuRIOS 2 Fieldbus and Remote I/O System Comparison

FieldConnex® from Pepperl+Fuchs in the Ketek tank farm:

FuRIOS 2 Fieldbus and Remote I/O System Comparison

says Dr. Thomas Tauchnitz, former manager oftechnology and projects at Aventis agents. Manyof the advantages of digital technology can onlytake effect if the planner uses the new possibili-ties in an intelligent way. But here the practicalexperience is missing. „The engineering teamsstill follow the conventional technology sincethey know all its nooks and crannies. One useshis leeways only after a certain experience isgained“, knows Manfred Dietz, head of the testlaboratory at Infraserv Höchst Technik. Thiscounts especially regarding the application ofmultivariable devices which had not been consi-dered in FuRIOS. “At 10 out of 2,000 measuringpoints we used the functionalities of multivari-able devices. Here we go one step further thanFuRIOS“, explains Bartscheit.

New technology means rethinkingAll team members underestimated the demandon training. One point which is unfavourable forfieldbus only at the first glance since the demandis much higher with Remote I/O technology.With Remote I/O Systems new field devices andnew operation philosophies show up all the timeand the personnel has to be trained anew for eachproject. „Somebody fit on Profibus is fit. It is onesingle learning process only”, confirms Dietz.“With each technology change the initial trai-nings take the most effort since one has to start atzero.” The manager of the test laboratory knowswhat he is talking about since he and his teamconducted all Profibus training sessions duringthis project.Everybody has to learn the new technology –installation personnel, planner, engineers andmanagers. “In order to take full advantage of thefieldbus benefits everybody has to know whatthis technology can do and what not”, says Dietz,and Tauchnitz adds: “Every trainee learns how toconnect 4 mA … 20 mA in his first year. How toconnect Profibus PA? This we had to work out,write down and teach to every employee.” Thespecialists are sure: this was a good investmentfor the Profibus newcomers. Dietz: „Companiescan save on trainings, but this will backfire du-ring operational maintenance.“

Time is moneyThe experiences of this pilot project show thatthere is savings potential in commissioning. “We

had to do a lot of things several times, since therewere modifications and adaptations ongoing allthe time“, explains Sven Seintsch of InfraservHöchst Technik. Changes during the planningprocess are daily business in pharma projects. “Inthat respect the advantage of fieldbus has to beestimated even higher since the user gets muchmore flexible”, says Dietz. “The first plantshowed how this reduced project time can beused sensible. Detailed planning of Process C&Ican start later, is installed later in the plant andthus saves a lot on modifications since the pro-duction process is already stable“, confirmsBartscheit. The logical consequence: the plant cango into operation earlier and this means moneyin the pocket.At no time any of the hardware problems endan-gered the faster commissioning. The Profibussoftware worked without problems, too. Thesame the project members could not state for theFDT/DTM software (see box). “The commissio-ning of the Profibus lines went without problemsin terms of the hardware. As an average it tookonly one day for 30 devices. One more advan-tage, compared to older times, is that marshallingfaults do not occur”, Seintsch sums it up. This isseen as a real success by the fieldbus experts.Bartscheit: „Ultimately a lot of apprehensionsproved wrong and we searched for problemswhich simply did not exist.“Once the teething problems are solved and theusers are familiar with the new technology, itsbenefit will be increased even more. Realizationof the many chances offered by fieldbus technolo-gy requires a certain experience. “At the momenteverybody is happy when the bus is working”,says Seintsch. “Aspects such as process optimiza-tion, diagnosis and maintenance are still someway out. Only after the technology is establishedthe user will start to pay attention to the mass ofadditional information he gets for free by thebus.” In the expert’s opinion the discussion onadded value of fieldbus is just starting.All concur in one more point: The new Profibusplant confirms the predication of FuRIOS regar-ding faster commissioning and more simpleinstallation. Fieldbus technology and fieldbusbarrier concept have definitely proven their suit-ability for daily use, and this gets around. At pre-sent there are two major projects and one smallerone with fieldbus technology in Industriepark

FuRIOS 2 Fieldbus and Remote I/O System Comparison

Höchst at Frankfurt, Germany. Furthermore thereare many more ongoing projects at other loca-tions of the former Höchst company. “The time isripe for digital technology. If we want to get outof this antiquated 4 mA ... 20 mA device techno-logy we desperately need the fieldbus“, says

fieldbus-fan Tauchnitz. „People who are notbrave enough by now cannot be helped. At thislocation there will be no new plant designedwithout fieldbus, this is certain!”

Dr. Christine Eckert, journalist

FDT/DTM

FuRIOS and the considerations regarding Ketek arefocused on the theme of fieldbus only. The study didnot cover field device engineering and therefore doesnot give any assessment on its advantages or disad-vantages. For the first time, the integration of the 15 different device types was done directly in thecontrol system. The project team decided to use theFDT/DTM Technology as integration tool. Sincethis technology is rather new it raised several ques-tions all through the project. It required a lot of persistence and competence of all involved persons tomaster these obstacles. At first glance this seems tobe contradictory to the statement ‘fieldbus is readyfor practical use’. However, at a closer look one seesthat device engineering is a completely different subject, independent of fieldbus.

Project scope

Control system ABB Melodie11 process near components, DCS‘s22 Profibus DP segments

250 Drives and Converters200 Profibus PA segments

1600 Profibus PA devices1230 Transducers,

160 Positioners190 Valve Boxes,20 Sensor Boxes15 different device types manufactured by ABB,

Endress+Hauser, Krohne, Knick, Pepperl+Fuchs, Samson, Vega

50 Segment Couplers Pepperl+Fuchs SK2470 Fieldbus Barriers Pepperl+Fuchs FieldBarrier

Field device engineering FDT/DTM technology in Control System

Less handicaps in explosion hazardous areas

Practice-oriented Power Supply Concepts for fieldbus reduce previous limitations

The first practical experienceswith the comprehensive use offieldbus technology in majorautomated production plantshave been presented at the 2004general assembly of NAMUR, theAssociation of Users of ProcessControl Technology. The decisivefactor for the positive appraisalwas the utilization of modernpower supply concepts which eli-minate fieldbus technology’s pre-vious limitations in explosionhazardous areas. High PowerTrunk Concepts for Ex-zones 1and 2 allow to get the optimumadvantage of fieldbus technologywhile maintaining the benefits ofexplosion protection by means ofenergy limitation.

Fig. 1: Fieldbus topology in line structure with trunk and spurs

Dipl.-Wirtsch.-Ing. ThomasKasten is responsible for theproduct group FieldConnex®

in the Marketing Departmentof Pepperl+Fuchs GmbH. Priorto that he held several posi-tions outside of Germany,covering technical marketingand service. He is a member ofthe Marketing Working Groupof the PROFIBUS UserOrganisation and of theEuropean Marketing Councilof the Fieldbus Foundation.

ContactTel. +49 621 776-2222pa-info@de.pepper-fuchs.com

fter long years of testingand theoretical analyses,plant control by fieldbustechnology is starting to

gain success in process automation. Atthe NAMUR general assembly inNovember 2004 several presentationsdescribed and positively appraised thefirst practical experiences in usingPROFIBUS PA as well as FOUNDA-TION Fieldbus H1 in major productionplants. A basic prerequisite for thisacceptance is the elimination of thelimitations which restricted the use offieldbus technology in explosion haz-ardous environments up to now. Thiswas achieved by the fieldbus barrierconcept which had been evaluated the-oretically two years ago in the FuRIOSStudy and now sees its practical use

in the first plants. A good example isthe Ketek plant of Aventis PharmaDeutschland which produces two pre-liminary substances of the novel antibi-otic Ketek by means of two productionlines comprising a total of 1,600PROFIBUS PA devices.

Basics of fieldbus use in explosionhazardous environmentsWhat’s so special about this fieldbusbarrier concept? To answer this ques-tion one has to consider the conditionsset in the fieldbus standard IEC 61158-2as well as the requirements of explo-sion protection in Zone 1/Class I, Div. 1by means of intrinsic safety accordingto IEC 60079-27. The fieldbus standardallows up to 32 devices at one segment

A

and requires for each field device a mini-mum working voltage of 9 V DC and aminimum current consumption of 10mA. The digital communication signalsare transmitted in Manchester II enco-ding by means of a ± 9 mA amplitude.All considerations are based on the ref-erence fieldbus cable Type A, which is ashielded twisted pair cable with con-ductor cross-sections of 0.8 mm2

(AWG18) and a loop resistance of 44Ohm/km. This cable transmits the digi-tal communication as well as the supplypower for the field devices. In order todisconnect individual devices from thebus without impairing the operation ofthe other devices each oneshould be connected to onecentral main line (trunk) bymeans of individual droplines. Fig. 1 shows such a recommended line structurewith a trunk and several con-nection spurs. Theterm ‚Power Supply’ summa-rizes the specific fieldbuspower supply units which aremandatory to combine thedigital signal of the fieldbushost with the direct current fordevice supply. These PowerSupplies are available in se-veral versions and variousoutput current levels. Basedhereon and the actual powerconsumption of the connecteddevices the maximum cablelength of a fieldbus segment iscalculated, keeping in mindthat the device farthest awayfrom the Power Supply has tomeet the above mentionedminimum values. The maxi-mum total cable length oftrunk plus all spurs is 1,900 m,according to IEC 61158-2.‚Intrinsic Safety’ EEx iachieves the explosion protec-tion by limiting the energy inthe segment so that a sparkpowerful enough to ignite thesurrounding atmosphere can-not develop. This allows livework at the devices duringoperation without specialsafety precautions. The otherside of the coin is a significantreduction of the supply cur-rent to 70 mA for EEx ia appli-cations which results in majorlimitations regarding cablelength and possible number ofdevices. Consequently thefieldbus was not attractive forexplosion hazardous environ-ments up to now. Furthermorethe required confirmation of

intrinsic safety is a rather complex cal-culation when using the original Entitymodel. The Fieldbus Intrinsically SafeConcept FISCO reduces this confirma-tion to the comparison of only a fewparameters and allows the slightly high-er power supply of 100 mA, howeverpaying for these advantages byincreased requirements on the devicetechnology and reduced maximum totalcable length.

Advantages of the fieldbusbarrier conceptStarting point of the development ofthis concept was the evaluation at

which elements of a fieldbus segmentrepair and maintenance work duringoperation might be necessary. Theseare the field devices and their connec-tion lines which should consequently beinstalled in EEx i. The need for livework at the passive wiring of trunk andfieldbus distribution modules isextremely unlikely, these can beinstalled using the explosion protectionmethod ‘increased safety’ EEx e resp.Div. 2 wiring methods. Thus the passivewiring is not subjected to energylimitation. State-of-the-art fieldbus bar-riers such as the FieldConnex®

FieldBarrier are designed for connecting

27

and daisy-chaining the trunk in EEx e,can be installed in Zone 1 resp. in Class I,Div. 2 with spurs reaching into Div. 1,and thus allow to lead a high supplypower into the explosion hazardousarea. When using modern PowerSupplies such as the modules of theFieldConnexTM system, this could be 400 mA with PROFIBUS PA and up to

1 A with FOUNDATION Fieldbus H1,significantly more than under EEx i con-ditions. Consequently this way of field-bus wiring is often described as ‚High-Power Trunk Conzept’. The four out-puts of the FieldBarrier deliver 40 mAEEx ia IIC and thus allow the connec-tion of intrinsically safe field deviceswith all their advantages, see fig. 2. The

confirmation of intrinsic safety isreduced to the respective device and itsconnection line and can be conductedaccording to Entity as well as, simpli-fied, according to FISCO. Even more,now the max. cable length of 1,900 m asdefined in IEC 61158-2 for non-Ex areasis possible in Zone 1, too, with fulladvantage of the max. spur length of120 m.

Protection against failures dueto short-circuit or overvoltageThe big advantage of fieldbus technolo-gy is the connection of several sensorsand actuators to one and the samecable, whilst with conventional point-to-point wiring each device needs itsindividual cable to the process-nearcomponent in the safe area. Therefore ashort-circuit would impair only thatone device. With fieldbus, however, alldevices at the segment would stopcommunicating. To prevent that eachoutput of the FieldBarrier is short-cir-cuit current limited to 45 mA, only thefaulty spur will go offline. Since theremaining devices in the segment keepcommunicating an easy and fast faultlocalisation in the control system isguaranteed. Furthermore each moduleof the FieldConnex® system is protectedagainst functional overvoltages. Forenhanced protection, e.g. by imple-menting a lightning protection zonesconcept according to IEC 61312-1, thereare surge protection modules specifical-ly optimized for fieldbus technologyavailable.

High Power Trunk Conceptsfor Zone 2 / Class I, Div. 2A fieldbus segment for Zone 2 can bedesigned similar to the fieldbus barrierconcept. Since the requirements inregard to explosion protection are notas stringent FieldConnex® SegmentProtectors are used instead ofFieldBarriers (fig. 3). For the trunk theexplosion protection method‚ nonsparking’ EEx nA is applied and allowsto lead high power into Zone 2. TheSegment Protectors are certified accor-ding to EEx nA[L] and can be installedin Zone 2 / Class I, Div. 2. Each outputis energy limited according to EEx nLIIC, the output current is 40 mA, theoutput voltage max. 31 V. Furthermoreeach output is individually short-circuitcurrent limited to 45 mA. Field deviceswith appropriate certification for Zone2 as well as intrinsically safe devicescan be connected. The evaluation of thesafety parametersfollows the Entity concept but is signifi-cantly simplified since each spur is cal-

Fig. 2: Topology for Zone 1 according to the fieldbus barrier concept

Fig. 3: High Power Trunk concept for Zone 2

culated individually. For the supply oftoday’s typical intrinsically safe devicesthe FieldConnex® Power Hub systemoffers modules with a voltage limitationto max. 23 V. By means of Power Hubmodules limited to 17 V segments fol-lowing the Fieldbus Non-IncendiveConcept FNICO according to IEC60079-27 Ed. 1 can be installed. FNICOis an adaptation of FISCO to Zone 2,however today there are only a fewFNICO certified field devices availableon the market. Furthermore the voltagelimitation reduces the possible totalcable length and number of fieldbus

devices. As the only benefit the confir-mation of the safety parameters by cal-culation can be omitted. In future therequirements for these voltage limita-tions will dwindle since more and morefield devices certified according to EExnL with Ui > 32 V are appearing onthe market. Thus the voltage limitationof the Segment Protector is sufficientand the advantages of the High-PowerTrunk Concept can be fully realized.

Fieldbus Power SuppliesHigh-Power Trunk Concepts for Zone 1and Zone 2 allow to transmit high sup-

ply power into explosion hazardousareas. On top of the above describedfunction of merging digital fieldbus sig-nal and supply current modernFieldbus Power Supplies offer far morefeatures for optimization of fieldbuscommunication and plant availability.Modular designed Segment Couplers(fig. 4) convert the RS485 transmissionphysics of PROFIBUS DP to the IEC61158-2 physics of PROFIBUS PA.Various Gateway Modules are available.To each Gateway several Power LinkModules can be connected, each onesupplying one fieldbus segment withup to 400 mA. The Segment Coupler’smaximum configuration allows thedesign of 20 PA Segments according tothe High-Power Trunk Concept with amedia redundant PROFIBUS DP con-nection to the Profibus master. TheFieldConnex® Power Hub (fig. 5) is amodular system, too, and allows theconnection of up to four FOUNDA-TION Fieldbus H1 segments to onecommon motherboard. Several variantswith host-specific system connectors areavailable. Depending on the require-ments on plant availability the mother-boards can be equipped with single orredundant electronic modules. Thenovel CREST technology stabilizes thefieldbus communication by minimizingthe disturbances due to noise and sup-pressing the resonances in the system.Very high requirements on the isolationof fieldbus segments can be met byusing modules with galvanic isolation.Diagnostic modules allow monitoringof various functional parameters ofPower Hub and fieldbus segment.Furthermore some variants of thePower Hub feature a novel short-circuitcurrent limitation of the connection lineto the host.

PerspectiveThe first practical experiences withcomprehensive fieldbus applications inmajor production plants are ratherencouraging. The presentations at theNAMUR general assembly concludedwith the statement: “Fieldbus is theright path to future”. However, theusers still handed over a list of wishesto manufacturers and fieldbus organisa-tions which was gladly accepted. Forexample the fieldbus barrier concept,since a few month, is explicitly men-tioned in the official Application Guideof the Fieldbus Foundation. In the nearfuture design and calculation of High-Power Trunk Concepts will be facilitat-ed by new tools such as the recentlyupdated FieldConnex® SegmentChecker software tool.

29

Fig. 4: FieldConnex® Segment Coupler with media redundant PROFIBUS DP connection and Power Link Modules for 2 PROFIBUS PA segments

Fig. 5: FieldConnex® Power Hub on Motherboard for four FOUNDATIONFieldbus H1 segments, redundant configuration

FOUNDATION FIELDBUS H1HIGH-POWER TRUNK TOPOLOGIES

High-Power Trunk Topologiesfor FOUNDATION Fieldbus H1

The FuRIOS study recommends the application of fieldbustechnology all throughout process production plants. Onlyin this way the advantages of this future oriented technologycan be realized to the fullest extend. The basis is a topologyconcept which neutralizes the previous limitations of fieldbusapplication in explosion hazardous areas. These High-PowerTrunk Topologies can easily be designed by means of acomprehensive Fieldbus Installation System such asFieldConnex®. Furthermore FieldConnex® offers all modulesand protection functionalities to ensure efficient plantoperation with high availability over many years. The expe-riences from plants planned and put into operation based onthese installation concepts confirm the expectations ofFuRIOS.A High-Power Trunk Topology consists of several basic functional groups. The FieldConnex® System offers for each functionality the appropriate, interoperable modules.

Fieldbus Power Hub■ Modular Power Supply System meeting the requirements of all applications and host systems■ High output current and several voltages for maximum number of devices in various explosion protection concepts■ Sophisticated isolation, redundancy and diagnosis concepts guarantee optimum plant availability■ Novel CREST technology minimizes signal distortions and ensures safe communication

Fieldbus Cables and Cord Sets■ Fieldbus cable type A according to fieldbus installation guidelines for optimum signal transmission■ Safe operation due to variants for all environmental conditions■ Versions with various plug connectors allow fast and fault-free installation

Junction Box■ Simple, individual connection of field devices to the fieldbus segment■ Quick and efficient fault localisation and rectification■ High flexibility due to various connection types and sturdy housings for harsh environments

Segment Protector■ Explosion protection in Zone 2 / Class I, Div. 2 by energy limitation of the outputs■ Increased plant reliability due to short-circuit and overload protection■ High flexibility due to various connection types and sturdy housings for harsh environments

FieldBarrier■ Explosion protection in Zone 1 / Class I, Div. 1 by intrinsically safe outputs according to FISCO and Entity■ Increased plant reliability due to short-circuit and overload protection■ Various shielding options guarantee minimization of signal distortions■ High flexibility due to various connection types and sturdy housings for harsh environments

Temperature Multi-Input, Valve Coupler, Fieldbus-Pneumatic Interface■ Easy integration of almost all conventional signals into fieldbus communication■ Power supply of the interfaces intrinsically safe via the fieldbus cable■ Integrated diagnostic functions for sensors and connection cables■ Direct actuation of solenoid and pneumatic valves

Surge Protector■ Protection of fieldbus host and instrumentation against voltage surges and lightning strikes■ Variants for various environmental conditions and explosion protection concepts■ Modular system with additional functionalities allow efficient plant operation

Segment Checker Design Software, Documentation, Services■ Efficient planning of optimized fieldbus topologies by ‚Drag and Drop’ on

www.segmentchecker.com■ Comprehensive installation guidelines and detailed information on all FieldConnex®

modules on www.fieldconnex.info■ Consulting services and support with fieldbus projects and specific system

solutions by your local Pepperl+Fuchs representative

FieldbusPowerSupply

FieldbusSignal

Transmission

FieldbusDistribution

FieldbusDistribution and

Energy Limitation

FieldbusDistribution andIntrinsic Safety

FieldbusProcess

Interfaces

SurgeProtection

Accessories,Tools

PROFIBUS PAHIGH-POWER TRUNK TOPOLOGIES

High-Power Trunk Topologiesfor PROFIBUS PAThe FuRIOS study recommends the application of fieldbustechnology all throughout process production plants. Onlyin this way the advantages of this future oriented technologycan be realized to the fullest extend. The basis is a topologyconcept which neutralizes the previous limitations of fieldbusapplication in explosion hazardous areas. These High-PowerTrunk Topologies can easily be designed by means of acomprehensive Fieldbus Installation System such asFieldConnex®. Furthermore FieldConnex® offers all modulesand protection functionalities to ensure efficient plantoperation with high availability over many years. The experiences from plants planned and put into operation basedon these installation concepts confirm the expectations ofFuRIOS.A High-Power Trunk Topology consists of several basic func-tional groups. The FieldConnex® System offers for each functionality the appropriate, interoperable modules.

Segment Coupler■ Adaptation of all PROFIBUS DP bit rates to PROFIBUS PA■ High power output for maximum number of devices per segment■ Modular concept allows flexible plant design■ Maximum safety due to galvanic isolation

Fieldbus Cables and Cord Sets■ Fieldbus cable type A according to fieldbus installation guidelines for optimum signal transmission■ Safe operation due to variants for all environmental conditions■ Versions with various plug connectors allow fast and fault-free installation

Junction Box■ Simple, individual connection of field devices to the fieldbus segment■ Quick and efficient fault localisation and rectification■ High flexibility due to various connection types and sturdy housings

for harsh environments

Segment Protector■ Explosion protection in Zone 2 / Class I, Div. 2 by energy limitation of the outputs■ Increased plant reliability due to short-circuit and overload protection■ High flexibility due to various connection types and sturdy housings for harsh environments

FieldBarrier■ Explosion protection in Zone 1 / Class I, Div. 1 by intrinsically safe outputs according to FISCO and Entity■ Increased plant reliability due to short-circuit and overload protection■ Various shielding options guarantee minimization of signal distortions■ High flexibility due to various connection types and sturdy housings for harsh environments

Valve Coupler, Sensor Interface, Fieldbus-Pneumatic Interface, MiniRIO■ Easy integration of almost all conventional signals into fieldbus communication■ Power supply of most interfaces intrinsically safe via the fieldbus cable■ Integrated diagnostic functions for sensors and connection cables■ Direct actuation of solenoid and pneumatic valves

Surge Protector■ Protection of fieldbus host and instrumentation against voltage surges and lightning strikes■ Variants for various environmental conditions and explosion protection concepts■ Modular system with additional functionalities allow efficient plant operation

Segment Checker Design Software, Documentation, Services■ Efficient planning of optimized fieldbus topologies by ‚Drag and Drop’ on www.segmentchecker.com■ Comprehensive installation guidelines and detailed information on all FieldConnex® modules

on www.fieldconnex.info■ Consulting services and support with fieldbus projects and specific system solutions by your

local Pepperl+Fuchs representative

FieldbusPowerSupply

FieldbusSignal

Transmission

FieldbusDistribution

FieldbusDistribution and

Energy Limitation

FieldbusDistribution andIntrinsic Safety

FieldbusProcess

Interfaces

SurgeProtection

Zubehör,Hilfsmittel

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FAX answer to +49 621 / 776 1400 _ Please send to: or by e-mail: info@de.pepperl-fuchs.com Pepperl+Fuchs GmbH Product Marketing, Mr. Thomas Kasten

Dear Madame / Sir, are you interested in more information on the future oriented fieldbus technology in process automation? Then please check the requested information. We will be happy to forward these documents to you. O FuRIOS 2 – the complete updated compendium of the user study ‚Fieldbus and Remote I/O System Comparison’ with additional information, insider interviews and practical experiences O Information on PROFIBUS PA O Information on FOUNDATION Fieldbus H1 O Please put me on the Pepperl+Fuchs fieldbus information distribution list. I will automatically receive the newest information on fieldbus technology and FieldConnex until further notice. O I currently work on fieldbus projects. Please contact me by phone. Are you interested in further product lines of Pepperl+Fuchs? Please name them below so we can send you the appropriate information: O Pepperl+Fuchs PA Highlights – the complete outline of all product lines for process automation O Conventional Interface Modules O Remote I/O Systems O Systems for HART Communication O Field devices for level control O Pepperl+Fuchs EXTEC – Controlling and monitoring in hazardous areas O Pepperl+Fuchs sensors and systems for factory automation ........................... ........................................................................................ (Date) (Signature)

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The respective authors take resonsibility for the contents of the articles.Subject to reasonable modifications due to technical advances.Copyright PEPPERL+FUCHS · Printed in Germany · Part. No. 127 960 03/05 01

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