What is field bus

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What is field bus

  1. 1. <Int> <Ind> <Rev> Technical Information Fieldbus Technical Information TI 38K03A01-01E Yokogawa Electric Corporation TI 38K03A01-01E 2-9-32, Nakacho, Musashino-shi, Tokyo, 180-8750 Japan ©Copyright Mar. 1998 Tel.: 81-422-52-5634 Fax.: 81-422-52-9802 3rd Edition Sep. 2002
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  3. 3. <Toc> <Ind> <Rev> i Introduction Fieldbus is an innovative technology for creating field information networks, and is attracting much interest among users and manufacturers of process control systems. This manual describes how users can introduce Fieldbus into their process control sys- tems, and also describes Yokogawa’s Fieldbus solutions and Yokogawa’s Plant Resource Manager (PRM) software package for managing plant assets in the field network era. Structure of This Manual This manual gives an overview of Yokogawa’s Fieldbus Solutions, and explains the ben- efits of adopting them. For the detail specifications for ordering, refer to the relevant Gen- eral Specifications. For engineering, installation, operation, and maintenance of the Fieldbus system and products described in this manual, refer to the relevant Instruction Manuals. This manual consists of three parts. Part A outlines Fieldbus prescribed by the Fieldbus Foundation and Yokogawa’s Fieldbus-ready products, Part B explains Fieldbus engineer- ing, installation, operation, and maintenance, and Part C outlines the Plant Resource Manager (PRM) software developed by Yokogawa. Part A consists of four sections. An overview of the functions and progress of international standardization of Fieldbus is given in Section A1, the features of Fieldbus in Section A2, Fieldbus-ready field devices in Section A3, and Yokogawa’s Fieldbus-ready systems in Section A4. Part B consists of five sections. Managing Fieldbus engineering is described in Section B1, design considerations in Section B2, construction considerations in Section B3, startup considerations in Section B4, and maintenance considerations in Section B5. Part C consists of four sections. An overview and glossary of Plant Resource Manager (PRM) are described in Section C1, the system configuration in Section C2, an overview of functions in Section C3, and the interface to the computerized maintenance management system in Section C4. Media No. TI 38K03A01-01E (MO) 3rd Edition : Sep. 2002 (YK) TI 38K03A01-01E Sep.01,2002-00 All Rights Reserved Copyright © 1998, Yokogawa Electric Corporation
  4. 4. <Toc> <Ind> <Rev> ii Target Readership for This Manual This manual is mainly intended for: • Managers who are planning to purchase a control system, Fieldbus, and Plant Resource Manager (PRM). • Instrumentation, electricity, maintenance, and computer engineers who are evaluating process control systems, Fieldbus, and maintenance management systems for purchase or who will be in charge of installing these systems. Trademarks • CENTUM is a registered trademark of Yokogawa Electric Corporation. • Ethernet is a registered trademark of Xerox Corporation. • Microsoft and Windows are registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries. • “FOUNDATION” in “FOUNDATION Fieldbus” is a registered trademark of the Fieldbus Foundation. • NI-FBUS Monitor is a registered trademark of National Instruments Corporation. • HART is a registered trademark of the HART Communication Foundation. • Oracle is a registered trademark of Oracle Corporation. • MAXIMO is a registered trademark of MRO Software, Inc. • Other product and company names may be registered trademarks of their respective companies (the TM or ® mark is not displayed). TI 38K03A01-01E Sep.01,2002-00
  5. 5. <Int> <Ind> <Rev> Toc A -1 Fieldbus Technical Information Part A Overview of Fieldbus and Yokogawa’s Fieldbus-ready Products TI 38K03A01-01E 3rd Edition CONTENTS A1. Progress of International Standardization of Fieldbus ....................... A1-1 A1.1 What is Fieldbus? ......................................................................................... A1-1 A1.2 Progress of Fieldbus Standardization ......................................................... A1-2 A1.3 Fieldbus Standard Specifications ................................................................ A1-4 A1.4 Yokogawa’s Efforts for Fieldbus Standardization ....................................... A1-5 A2. Features of Fieldbus ............................................................................. A2-1 A2.1 Comparison with Conventional Communication ........................................ A2-2 A2.2 Reduced Wiring Cost .................................................................................... A2-4 A2.3 Improved Transmission Accuracy ............................................................... A2-6 A2.4 Enhanced Data Transmission ...................................................................... A2-8 A2.5 Distributed Functions ................................................................................... A2-9 A2.6 Interoperability ............................................................................................ A2-10 A3. Fieldbus-ready Field Devices ............................................................... A3-1 A3.1 Changes in Transmitters .............................................................................. A3-3 A3.1.1 Accuracy Improvement due to Digitalization .................................... A3-4 A3.1.2 Multi-sensing Function Equipment .................................................. A3-6 A3.1.3 Multifunction Equipment ................................................................. A3-7 A3.2 Actuator ......................................................................................................... A3-8 A3.3 Using Self-diagnostics Function................................................................ A3-10 A3.4 Yokogawa’s Fieldbus-ready Field Devices Line-up .................................. A3-11 A4. Yokogawa’s Fieldbus-ready Systems .................................................. A4-1 A4.1 Fieldbus Support in Yokogawa’s CENTUM Control Systems ..................... A4-1 A4.1.1 Fieldbus Support in FCS for FIO of CENTUM CS 3000 ................... A4-2 A4.1.2 Fieldbus Support in FCS for RIO and Compact FCS of CENTUM CS 3000 ......................................................................... A4-4 A4.1.3 Fieldbus Support in CENTUM CS 1000 .......................................... A4-6 A4.1.4 Fieldbus Support in CENTUM CS ................................................... A4-8 A4.2 Connection of FF Devices from Other Vendors to Yokogawa’s CENTUM Control Systems .................................................... A4-10 TI 38K03A01-01E Sep.01,2002-00
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  7. 7. <A1. Progress of International Standardization of Fieldbus> A1-1 A1. Progress of International Standardization of Fieldbus This section describes what is Fieldbus, the progress of standardization of Fieldbus, Fieldbus standard specifications, and Yokogawa’s efforts toward standardization of Fieldbus. A1.1 What is Fieldbus? The Fieldbus Foundation gives the following definition: “Fieldbus is a digital, two-way, multi- drop communication link among intelligent measurement and control devices.” Fieldbus is gradually replacing 4 to 20 mA standard instrumentation signals used to transfer measurement and control data between control room and plant floor. It is one of several local area networks dedicated for industrial automation. Modern industries in the 21st century could not survive without information technologies and networks. From production line to enterprise level, digital communication supports all economic and social activities with powerful modern technologies. Fieldbus is one such technology and cannot be separated from others. Fieldbus is at the lowest level in the hierarchy and exchanges information with higher-level databases. IEC (International Electrotechnical Commission) prescribes the following seven definitions standardized by the standard organizations (shown by their trademarks) as international standards of Fieldbus: • FOUNDATION Fieldbus and HSE • ControlNet • PROFIBUS and PROFInet • P-NET • WorldFIP • INTERBUS • SwiftNet FOUNDATION Fieldbus, which is one of the seven definitions, is a standard defined by the Fieldbus Foundation. Yokogawa, a member of the board of directors of the Fieldbus Foundation since its inception, has participated closely in developing the Fieldbus specifications. Unfortunately, the Fieldbus standards of IEC list the definitions of many standard organiza- tions. In practice, all major makers and users are now participating in the Fieldbus Founda- tion, and many products based on the FOUNDATION Fieldbus specifications are devel- oped and marketed. Yokogawa considers that FOUNDATION Fieldbus will be used as widely as the fieldbus for process control systems in industry. Yokogawa’s CENTUM CS 3000, CENTUM CS 1000, and CENTUM CS support FOUNDATION Fieldbus. FOUNDATION Fieldbus H1 (Low Speed Voltage Mode) is called FOUNDATION Fieldbus, Fieldbus, H1 Fieldbus, FF, or FF-H1 in this manual. The sophisticated communication functions of Fieldbus allow distributed control via Fieldbus devices and optimal control by interfacing with a field control station (FCS). TI 38K03A01-01E Sep.01,2002-00
  8. 8. <A1. Progress of International Standardization of Fieldbus> A1-2 A1.2 Progress of Fieldbus Standardization The international standards of Fieldbus have been unified by IEC/TC65/SC65C WG6 (International Electrotechnical Commission/Technical Committee 65/Sub-Committee 65C/ Working Group 6), ISA (The International Society for Measurement & Control) SP50 Committee (which defined 4 to 20 mA analog signals as the standard electronic instrumentation signal), and the Fieldbus Foundation. Recently, the Fieldbus Foundation, a private organization formed to promote Fieldbus, is supporting the international unification of Fieldbus standards. Yokogawa, a member of the board of directors of the Fieldbus Foundation since its inception, is also promoting FOUNDATION Fieldbus worldwide. Recognition as a Standardization Work Item In 1984, the standardization concept for the next-generation digital communication protocol for field devices was first proposed to the IEC, which is to replace the 4 to 20 mA analog transmission. In 1985, IEC/TC65/SC65C recognized the digital communication protocol as a new standardization work item and named it Fieldbus. IEC/TC65/SC65C WG6, and the ISA SP50 Committee, which had already commenced discussions on Fieldbus standard- ization, consented to jointly standardize Fieldbus. Establishment of the Fieldbus Foundation The standardization of Fieldbus will have a great effect on industry. Many views were presented at the ISA SP50 Committee, delaying the standardization of Fieldbus. To make up for lost time and promote the production of Fieldbus, ISP (Interoperable Sys- tems Project) was organized by Yokogawa, Fisher Control, Rosemount, and Siemens in August 1992. In February 1993, ISP became ISP Association. In March 1993, WorldFIP (Factory Instrumentation Protocol) was jointly created by Honeywell, A-B (Allen-Bradley), CEGELEC, Telemechanique, and several other companies. A consensus was then obtained amongst customers that Fieldbus should conform to the internationally unified standard. In September 1994, in accordance with this decision, the ISP Association and WorldFIP North America were combined to form the Fieldbus Founda- tion. TI 38K03A01-01E Sep.01,2002-00
  9. 9. <A1. Progress of International Standardization of Fieldbus> A1-3 Process of Standardization IEC/TC65/SC65C WG6 and the ISA SP50 Committee started Fieldbus standardization. By establishing the Fieldbus Foundation, a structure has been built to develop internationally unified instrumentation specifications. The process of Fieldbus standardization is shown below. WorldFIP North America ISA SP50 Committee The Fieldbus ISP Foundation FF-H1 standard is defined and published. IEC 1984 1985 1990 1992.8 1993.3 1994.9 1996.8 • 1984 The standardization concept of digital communication protocol for field devices was proposed to IEC. • 1985 In IEC/TC65/SC65C, the new standardization work item was recognized and named Fieldbus. • 1990 The ISA SP50 Committee and IEC/TC65/SC65C/WG6 decided to collaborate on Fieldbus standardization. • August, 1992 ISP was organized. • March, 1993 WorldFIP was established. • September, 1994 The ISP Association and WorldFIP North America were combined into The Fieldbus Foundation. Since then, The Fieldbus Foundation has developed the internationally unified instrumentation specifications. The Fieldbus standardization structure is configured by IEC, ISA, and The Fieldbus Foundation. • August, 1996 Fieldbus Foundation defined and published FOUNDATION Fieldbus H1 standard (low speed voltage mode). A010201E.EPS Figure Process of Fieldbus Standardization TI 38K03A01-01E Sep.01,2002-00
  10. 10. <A1. Progress of International Standardization of Fieldbus> A1-4 A1.3 Fieldbus Standard Specifications There are two kinds of Fieldbus physical layer specifications standardized by IEC61158-2 and ISA S50.02: low-speed and high-speed Fieldbus specifications. But the high-speed Fieldbus specification is not adopted and High Speed Ethernet (HSE) specification is added as additional type. IEC/ISA Standard Specifications The low-speed and high-speed Fieldbus specifications are standardized as shown in the tables below. Table Fieldbus Specifications (Standard) Low-Speed Fieldbus High-speed Fieldbus High-speed Fieldbus Item FF-H1 FF-H2 FF-HSE (High Speed Ethernet) Subsystem integration Positioning Field device integration Subsystem integration Data Server integration 1.0 Mbps (in 1 Mbps mode or Transmission Speed 31.25 kbps high-speed current mode) 100 Mbps 2.5 Mbps (in 2.5 Mbps mode) Max. 32 devices/segment Number of connectable devices Number of Connectable Max. 32 devices/segment (Using repeaters increase the depend on the subsystem devices number of connectable devices.) integrated by FF-HSE. • Twisted pair cable (shielded) • Twisted pair cable (shielded) Cable • Twisted pair cable (shielded) • Optical Fiber • Optical Fiber Power supply to Enabled Enabled No connected devices Intrinsic safety Enabled Enabled No Redundancy No (*1) Enabled Enabled Example of connected Transmitter, control valve, Multicomponent analyzer, Multicomponent analyzer, devices field multiplexer, etc. PLC, remote I/O, etc. PLC, remote I/O, etc. A010301E.EPS *1: Yokogawa has developed dual-redundant configuration of ALF111 Fieldbus Communication Module for FF-H1. Table Type of Low-speed Fieldbus Cables and Transmissible Length Max. length of cable Type of cable Cable specifications (reference value) Type A: Individually-shielded twisted pair cable #18AWG (0.82 mm2) 1,900 m 2 Type B: Overall-shielded twisted pair cable #22AWG (0.32 mm ) 1,200 m 2 Type C: Unshielded twisted pair cable #26AWG (0.13 mm ) 400 m Type D: Overall-shielded non-twisted cable #16AWG (1.25 mm2) 200 m A0130302E.EPS Note: Yokogawa recommends the use of Type A. Usage of Types B and D is restricted. Yokogawa does not recommend the use of Type C. SEE ALSO For the cable specifications, refer to Section B2 of Part B. TI 38K03A01-01E Sep.01,2002-00
  11. 11. <A1. Progress of International Standardization of Fieldbus> A1-5 A1.4 Yokogawa’s Efforts for Fieldbus Standardization Yokogawa, a member of the board of directors of the Fieldbus Foundation, has played a leading role in the international standardization of Fieldbus standards. Services for Fieldbus Support Devices Yokogawa has worked hard to promote Fieldbus, and provided the following services to add value for customers: Product Development Yokogawa has developed and provided a variety of products that support Fieldbus, ranging from various field devices to an integrated production control system, CENTUM CS 3000. Development of Field Device Management and Diagnostics Packages Yokogawa has developed and provided field device management and diagnostics pack- ages which support enhanced field information. TI 38K03A01-01E Sep.01,2002-00
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  13. 13. <A2. Features of Fieldbus> A2-1 A2. Features of Fieldbus Fieldbus is a bidirectional digital communication protocol for field devices. Fieldbus technology drastically changes process control systems and is gradually replacing the standard 4 to 20 mA analog transmission that most current field devices employ. Fieldbus has the following features: • Because multiple devices can be connected, and multivariables can be trans- mitted on a single cable, thus reducing the number of cables, wiring costs are reduced. • A digital transmission protocol ensures accurate information processing and hence strict quality control. • Multiplex communications allow other information as well as process variables (PVs) and manipulated variables (MVs) to be transmitted from field devices. • Communication between field devices allows truly distributed control. • Interoperability enables devices from different manufacturers to be combined. • A broad choice of devices from any manufacturer permits flexible system construction. • Instrumentation systems, electrical devices, FAs, BAs, OAs, and analyzers can be integrated. • Some adjustments and inspections of field devices can be performed from the control room. The following sections explain the advantages of Fieldbus and the effect of Fieldbus on process control systems. TI 38K03A01-01E Sep.01,2002-00
  14. 14. <A2. Features of Fieldbus> A2-2 A2.1 Comparison with Conventional Communication The Fieldbus communication protocol is superior to analog transmissions and hybrid communications in information accuracy, transmission speed, and transmission amount. It also offers superiority to those transmissions and communications in functionality, including the ability to communicate between connected devices and to communicate bidirectionally. Analog Transmission An analog transmission is an information transmission technique using analog signals with a direct current of 4 to 20 mA. The topology, which is a one-to-one system, allows only one field device to be connected to a single cable. The transmission direction is one-way. Therefore, two different cables must be provided: one to acquire information from the field device, and the other to transmit control signals to the field device. Hybrid Communication A hybrid communication is a communication technique in which field device information is superimposed as digital signals on the conventional 4 to 20 mA analog signal. In addition to analog transmission capabilities, it is possible to remotely set up the field device range and zero-point adjustment. Also, maintenance information such as self-diagnostics of the field device can be obtained using a dedicated terminal. Hybrid communication protocols were developed independently by each manufacturer, and so devices from different manufacturers cannot communicate with each other. With the Yokogawa BRAIN system or the hybrid communication systems of other manufacturers, the self-diagnostics information cannot be exchanged between field devices from different manufacturers. A hybrid communication mainly supports 4 to 20 mA analog transmission, though it also allows digital data communication. The digital data communication speed through the hybrid communication is slower than that through the Fieldbus communication. TI 38K03A01-01E Sep.01,2002-00
  15. 15. <A2. Features of Fieldbus> A2-3 Fieldbus Communication The Fieldbus communication protocol, which is different from analog transmissions or hybrid communications, supports a perfect digital signal communication system. In addi- tion, the Fieldbus communication supports bidirectional communication, thus allowing more types and a larger amount of data to be transmitted in comparison to analog transmission and hybrid communication. This communication removes the restriction which allows only one field device to be con- nected to a single cable in an analog transmission system. Multiple field devices can be connected to a single Fieldbus cable. Also, since this communication is internationally standardized, interoperability of field devices is guaranteed. Fieldbus solves the problems of hybrid communications, such as slow digital transmission speeds and lack of interoperability. A comparison between the conventional 4 to 20 mA analog transmission, hybrid communi- cation, and Fieldbus communication protocols is shown below. Table Comparison of Communication Protocols Fieldbus Hybrid Analog Topology Multi-drop One-to-one One-to-one 4 to 20 mA DC Transmission analog signal 4 to 20 mA DC Digital signal analog signal method + digital signal One-way Transmission (analog signal), Bidirectional One-way direction bidirectional (digital signal) Partially multiplex Type of signal Multiplex signal Single signal signal Differs depending Standard Standardized in 1996. Standardized on manufacturers A020101E.EPS TI 38K03A01-01E Sep.01,2002-00
  16. 16. <A2. Features of Fieldbus> A2-4 A2.2 Reduced Wiring Cost The introduction of Fieldbus reduces wiring cost by means of multi-drop connections and multivariable transmission. Multi-drop Connections Connecting multiple field devices to a single cable is known as multi-drop connections, and the reduction in the number of cables has many advantages. An example of multi-drop connections is shown below. Fieldbus Multi-drop connection To the system Field device Field device A020201E.EPS Figure Multi-drop Connections In a conventional analog transmission system, only one field device can be connected to a single cable that leads to a system. Multi-drop connections connect multiple field devices to a single cable, and so allow additional field devices to be connected to a cable which has already been laid. In the past, it was costly to connect multiple field devices. Using a Fieldbus communication system, it is possible to connect a large number of field devices to the Fieldbus because of low wiring cost by multi-drop connections. This expands the scale of process control systems and promotes a higher level of plant automation. TI 38K03A01-01E Sep.01,2002-00
  17. 17. <A2. Features of Fieldbus> A2-5 Multivariable Detection and Transmission Multivariable means multiple measured variables, and multivariable detection means that one field device can detect multiple measured variables, which is also called multi-sensing. A conventional analog transmission system requires one cable for each measured variable. Fieldbus supports multivariable transmission. Therefore, a field device can transmit all measured variables detected by the field device via a single cable. The difference in wiring a control valve between analog and Fieldbus communication systems is shown below. Conventional Analog Transmission System Fieldbus Communication System Fieldbus Positioner control signal Lower limit signal Positioner control signal Lower limit signal Valve opening signal Valve opening signal Upper limit signal Upper limit signal Positioner Positioner Control valve Control valve Number of cables Number of cables • Positioner control signal : 1 pair • Fieldbus : 1 pair • Valve opening signal : 1 pair • Upper/lower limit signal : 2 pairs Total : 4 pairs A020202E.EPS Figure Difference in Detection and Transmission between Analog Transmission and Fieldbus Communication Systems In the conventional analog transmission system, the control output signal to the positioner is usually transmitted. In a Fieldbus communication system, multiple pieces of information such as control signals, limit signals, and valve opening signals can all be detected and transmitted. Multivariable detection and transmission can be used for: • Monitoring the condition of the steam heat tracing of differential pressure transmitters by ambient temperature information. • Detecting clogging in impulse lines by static pressure information. Many other pieces of information will also be used to expand measurement and control capabilities. TI 38K03A01-01E Sep.01,2002-00
  18. 18. <A2. Features of Fieldbus> A2-6 A2.3 Improved Transmission Accuracy Fieldbus improves transmission accuracy by eliminating errors that occur during data transmission in the conventional analog transmission system. Removing Error Factors The following three factors cause errors in the conventional analog transmission system. • D/A conversion in the field device • Analog signal transmission • A/D conversion in the system For example, if data is transmitted from a field device with a microprocessor in the conven- tional analog transmission system, an error may result during A/D and D/A data conversion. Fieldbus eliminates transmission errors and conversion errors during data transmission. The difference in transmission accuracy between the conventional analog transmission system and the Fieldbus communication system is shown below. Conventional Analog Transmission System Error due to data conversion Error due to data conversion 4 to 20 mA analog signal Sensor µP D/A A/D System Data transmission direction PVs with transmission errors Error due to analog signal transmission Upgrade to Fieldbus Fieldbus Communication System Digital signal Sensor µP Modem Modem System Data transmission direction PVs without transmission errors A020301E.EPS Figure Difference in Transmission Accuracy between Analog Transmission and Fieldbus Communication Systems Fieldbus transmits data using digital signals. Signal transmission errors rarely occur in digital signal transmission, unlike analog signal transmission. In addition, Fieldbus does not need A/D and D/A conversions because data is always transmitted digitally. Fieldbus removes these three error factors, improving transmission accuracy. System reliability also improves as a result of higher transmission accuracy, which allows stricter quality control and greater production efficiency. TI 38K03A01-01E Sep.01,2002-00
  19. 19. <A2. Features of Fieldbus> A2-7 Making the Most of Field Device Accuracy Improved data transmission means accurate transmission of data which is detected by field devices. Especially, digital field devices reduce transmission errors and conversion errors of digital signals detected by sensors. Therefore, a Fieldbus communication system can take advantage of the performance of high-accuracy field devices. TI 38K03A01-01E Sep.01,2002-00
  20. 20. <A2. Features of Fieldbus> A2-8 A2.4 Enhanced Data Transmission In a Fieldbus communication system, many pieces of field information as well as PVs and MVs can be exchanged between field devices. Fieldbus can transmit many kinds of data bidirectionally, so the system offers more advanced functionality than a conventional analog transmission system. Various Types of Data Transmission Fieldbus can transmit various types of data. The conventional analog transmission system cannot transmit data other than PVs and MVs. Although hybrid communication, an analog communication protocol with a digital data transmission function, allows various types of data transmission, the hybrid communication protocol has the following problems: • The transmission speed is slow. • Only one-to-one communication between a system and a field device is possible. Fieldbus solves the problems associated with hybrid communication. • The transmission speed is fast. • Multiple pairs of devices can simultaneously communicate among a system and field devices, and between field devices. Transmission of various types of data allows the following advanced functionalities. • Since past maintenance information can be easily acquired, maintenance efficiency improves. • Device management such as field device master file creation can be automated. Bidirectional Communication Fieldbus transmits multiplexed digital information. This enables the system to perform bidirectional communication, which is not possible with the conventional analog transmis- sion system. Data Exchange between Field Devices Distribution of control to field devices is made possible by exchanging data between them. TI 38K03A01-01E Sep.01,2002-00
  21. 21. <A2. Features of Fieldbus> A2-9 A2.5 Distributed Functions The use of Fieldbus implements integrated control over the entire plant and autonomous distributed control. Installing Advanced Functions in Field Devices Fieldbus allows the exchange of field information used for control in addition to PVs and MVs. Field devices with a calculation function and other functions can thus be adjusted from a system. Although some functions such as correction computation have been installed in current field devices, various functions that use more information are expected to be included in future field devices. By doing this, a field device such as a positioner will be able to field-adjust valve control characteristics. Distributing Functions to the Field Depending on the requirements of the processes to be controlled, field devices are equipped with advanced functions that provide some control functionality that used to be provided by a system. Distribution of control to field devices will change system functions. Functions of Field Devices and System By increasing the functionality of field devices and distributing control functions, the func- tions will vary between field devices and system. For example, the user can install the PID function for each control object in a field device or a system. If the relation between loops is tight and they cover a wide range in a large-scale plant, the PID function will be generally installed in the system. Conversely, if the loops are relatively independent in a small-scale plant, the PID function may be installed in a field device. In an oil refinery or a petrochemical, for example, the PID function is closely related to complex control, advanced control, optimized control, and integrated control over the entire plant. Therefore, excluding some independent control loops, the PID function will be in- stalled in the system. TI 38K03A01-01E Sep.01,2002-00
  22. 22. <A2. Features of Fieldbus> A2-10 A2.6 Interoperability Conventional hybrid communications can transmit digital signals, but information exchange between devices of different manufacturers is difficult because each device uses its manufacturer’s protocol. In Fieldbus communication, international standardization of the protocol ensures the Interoperability between FF devices including FF interface card in host system. FF devices allow digital data to be exchanged between devices from different manufacturers. There- fore, the freedom to configure the process control system increases since there is no need to choose one device manufacturer. The Fieldbus Foundation prescribes the interoperability test procedure called Interoperability Test (IT) to ensure the Interoperability for the FF devices, and the FF de- vices that passed the IT are registered to the Foundation, and published on the Fieldbus Foundation’s web site (http://www.fieldbus.org/). Yokogawa registered EJA series transmit- ter as the world’s first vendor. Fieldbus Foundation started the Host Interoperability Support Test (HIST) for host com- puter in September 2000. On September 14, 2000, Yokogawa’s CENTUM series were certified as the system able to execute the Host Interoperability Support Test (HIST), becoming the world’s first vendor to carry out the HIST. The HIST is to prove the interoperability between the host computer and devices. The various devices from different manufacturers has been tested by the CENTUM series with the HIST procedure, and the interoperability has been proved. TI 38K03A01-01E Sep.01,2002-00
  23. 23. <A3. Fieldbus-ready Field Devices> A3-1 A3. Fieldbus-ready Field Devices When Fieldbus is introduced, the type and amount of transmissible information will drastically increase. Also, bidirectional communication of digital information can take place between a field device and a system, and between field devices. To make the most of communication improvements and to satisfy more advanced needs, big changes are taking place with field devices. This section explains the differences in field devices when Fieldbus is introduced in a communication system. Difference between Analog Transmission and Fieldbus Communication Systems The Fieldbus communication system transmits information differently from the conventional analog transmission system. It has the following capabilities: • A large amount of information can be transmitted. • There are many types of transmissible information, both control and non-control information. • Digital information can be transmitted. • Bidirectional communication is possible between a field device and a system. • Bidirectional communication is possible between field devices. According to those differences, the information handled by field devices (field information) changes significantly. The differences between analog transmission and Fieldbus communication systems is shown below. Conventional Analog Transmission System Fieldbus Communication System Computer Control bus gateway Control Control valve station Sequencer Fieldbus Controller gateway Sequencer Field junction box Remote I/O card, terminal board 4 to 20 mA analog communication cable One variable Multivariable Bidirectional communication One way Bidirectional is possible between the control valve and flowmeters. Flowmeter Flowmeter Control valve A030001E.EPS Figure Difference between Analog Transmission and Fieldbus Communication Systems TI 38K03A01-01E Sep.01,2002-00
  24. 24. <A3. Fieldbus-ready Field Devices> A3-2 Advanced Functionality of Field Devices By making the most of Fieldbus communication system features, it is possible to have more advanced control over the system. As a result, more advanced functionality is required in field devices. For example, by transmitting self-diagnostics information from a field device to the system, with the appropriate timing, the system can control the field device according to its status and can predict a problem in the field device. Also, by exchanging data (PV, MV, etc.) between field devices, autonomously distributed control of multiple field devices will be possible. Once the main power to the process control systems was changed from air to electricity, new electric-powered field devices appeared on the market. Similarly, when process control systems are changing from analog transmission to Fieldbus communication, new field devices that support Fieldbus communication capabilities are appearing on the mar- ket. Field devices are primarily categorized into transmitters and actuators. Fieldbus will bring about changes in both components. The following sections describe what changes will occur in transmitters and actuators. TI 38K03A01-01E Sep.01,2002-00
  25. 25. <A3. Fieldbus-ready Field Devices> A3-3 A3.1 Changes in Transmitters The Fieldbus communication system can transmit digital information in a single line. There- fore, the function of a transmitter is changing greatly. In a conventional analog transmission system, transmitters are primarily designed to transmit the PV value to be measured to the system. This is because the analog transmis- sion system performs one-way communication, from a field device to a system, or vice versa. By using the Fieldbus communication system, the type and amount of information being transmitted through a single cable will increase drastically, and will be far greater than that of a conventional analog transmission system. In addition, bidirectional communication can be performed between a field device and a system, and between field devices. Since digital information can be transmitted to field devices without conversion, information will be much more reliable. TI 38K03A01-01E Sep.01,2002-00
  26. 26. <A3. Fieldbus-ready Field Devices> A3-4 A3.1.1 Accuracy Improvement due to Digitalization Since the Fieldbus communication system transmits information digitally, it can transmit the measured data from a transmitter to the system with minimum error. Many transmitters with drastically higher accuracy come to market. Improvement of Transmission Accuracy A transmitter with the conventional analog transmission handled a PV value as a percent- age (0 to 100 % relative value) of the measuring range, and transmitted this value to the system after converting to a 4 to 20 mA analog signal. The system converted the 4 to 20 mA analog signal that was transmitted to the digital signal in engineering unit, and used it. Errors occur during these signal conversion. In contrast, a transmitter with the Fieldbus communication handles a PV value in engineer- ing units and transmits this value, without conversion, to the system as a digital signal. The system uses the digital signal as it was transmitted. The Fieldbus communication system does not require signal conversion, thereby eliminating conversion errors that occur during transmission of measured data. The Fieldbus communication system provides for higher data transmission accuracy compared to the analog transmission system. Using the example of the orifice flowmeter which uses a differential pressure transmitter, the difference in transmission accuracy between the analog transmission and Fieldbus communication systems is described below. In a conventional analog transmission system, the differential pressure generated at the orifice, proportional to the square of the flow rate, was measured by a differential pressure transmitter and transmitted to the system after converting to a 4 to 20 mA signal. If the differential pressure, P at the orifice is 2 kPa when the flow rate is 20 Nm3/h, the output signal of the differential pressure transmitter will be as shown in the table below. The analog transmission system generates an error when this output signal is converted to a digital signal in the system side. If the differential pressure is converted to a flow rate on the system side, the transmission error will be changed by the flow rate because this conversion is not linear as shown in Figure below. Table Analog Signal Data Differential Output Flow rate pressure 4 mA 0 kPa 0 N m3/h 20 mA 2 kPa 20 N m3/h A030101E.EPS Flow rate Differential pressure A030102E.EPS Figure Relationship between Differential Pressure and Flow Rate TI 38K03A01-01E Sep.01,2002-00
  27. 27. <A3. Fieldbus-ready Field Devices> A3-5 In contrast, the Fieldbus communication system transmits the flow signal in engineering units as a digital signal. Therefore, there is no error during transmission. In this example, the differential pressure generated by the orifice is calculated and converted to a flow rate by the microprocessor of the differential pressure transmitter. The flow signal in engineering unit is transmitted to the system as a digital signal without conversion. Improvement of Transmitter Measuring Accuracy If the transmission accuracy is improved by the Fieldbus communication, the improvement of transmitter measuring accuracy will be a factor in improving the accuracy of the entire process control system. To perform measurements at higher accuracy, field devices that employ a superior measurement principle will be widely used. For example, conventional mechanical flow meters and level meters will be replaced by electric flow meters and level meters that employ digital technology. Since the Fieldbus communication system transmits the measured data in engineering units, without dependence on measuring range, a transmitter with a wide measuring range will show the original measuring performance. The width of the measuring range is one of the most important factors in determining the quality of transmitters. TI 38K03A01-01E Sep.01,2002-00
  28. 28. <A3. Fieldbus-ready Field Devices> A3-6 A3.1.2 Multi-sensing Function Equipment The function used to measure multiple variables with a single transmitter is known as the multi-sensing function. In a Fieldbus communication system, it is possible to transmit multiple pieces of information over a single cable. To make the most of this Fieldbus feature, users will demand transmit- ters equipped with a multi-sensing function. In a conventional analog transmission system, a transmission cable with a pair of wires is required to transmit one measured value. For example, a transmitter that can perform multiple measurements, such as the Coriolis flowmeter, requires multiple cables to transmit multiple measurement variables. The Fieldbus communication system allows the Coriolis flowmeter to transmit multiple measurement variables via a single cable. Transmitters that have been used to perform only one measurement are enhanced to perform the multi-sensing function using the Fieldbus communication system. For example, the differential pressure transmitter is able to measure process pressure, ambient temperature, etc., in addition to flow rate, which was the transmitter’s original function. If a temperature sensor for measuring the process temperature is combined with this differential pressure transmitter, all flow rate, pressure, and temperature variables necessary for process control will be measurable by the transmitter alone. Possible data that will be gained by multi-sensing function for the main transmitters are shown below. • Differential pressure flowmeter: Mass flow, volume flow, pressure, temperature • Magnetic flowmeter: Volume flow, conductivity, temperature • Vortex flowmeter: Mass flow, volume flow, temperature, pressure • Coriolis flowmeter: Mass flow, volume flow, density, temperature • Differential pressure level meter: Liquid level, density and specific gravity, tank internal pressure, temperature • Ultrasonic level meter: Liquid level, temperature • Temperature transmitter: Humidity, ambient temperature, vibration • pH meter: pH, temperature • Conductivity meter: Conductivity, temperature TI 38K03A01-01E Sep.01,2002-00
  29. 29. <A3. Fieldbus-ready Field Devices> A3-7 A3.1.3 Multifunction Equipment A Fieldbus communication system can transmit other information in addition to the PV value. To make the most of this feature, the transmitter is expected to calculate the multiple values and process them into the required information for control. A transmitter that incorporates multiple functions, such as the calculation function, is known as a multifunction transmitter. Multifunction transmitters increase for a Fieldbus communi- cation system. The main function of transmitters used in a conventional analog transmission system is to measure a PV value at high-accuracy and transmit it. To do this, additional devices are used for converting the measured PV value into the information necessary for control. A multifunction transmitter can calculate the PV value in engineering units required by the user and transmit it to the system. If a multifunction transmitter is used in combination with the above multi-sensing function, it is possible to drastically simplify the process control system. For example, assume that there is a differential pressure transmitter which can multi-sense the flow rate, pressure, and temperature. If a calculation function is added to this differential pressure transmitter, it allows the transmitter to calculate the mass flow rate after tempera- ture-pressure compensation using the measured flow rate, pressure, and temperature, and before executing transmission. To attain the above functions, a conventional analog transmission system would require three transmitters, one each for flow rate, pressure, and temperature, and an additional calculator for temperature-pressure compensation. A single multifunction transmitter with multi-sensing can process all of this. This will not only drastically reduce the instrumentation cost, but will also improve the reliability. TI 38K03A01-01E Sep.01,2002-00
  30. 30. <A3. Fieldbus-ready Field Devices> A3-8 A3.2 Actuator Fieldbus is expected to offer many possibilities for actuators. This section explains, using a typical control valve actuator, the changes that are taking place in actuators. Control Valve Changes The progress brought about by Fieldbus communication will drastically change the role of the control valve. A control valve with a conventional analog transmission controls a valve using a positioner according to the MV value transmitted from the system. On the other hand, a control valve with Fieldbus communication does not only control the valve to a constant opening, but also returns the valve opening value back, with respect to the MV value, and outputs limit signals to the system. This will promise more stabilized control of the system without valve opening meter and limit switches separately. Also, this valve and its positioner are able to perform valve characteristic modifications, temperature compensations, etc., which were usually made by the system. This will make it possible to compensate for valve operation as close to the process state as possible, while monitoring the valve characteristics. If this positioner and valve are combined with a flowmeter, the feedback control of a control valve, which is currently handled by the system, will be handled by only the control valve. Features of control valves with the Fieldbus communication are summarized next. TI 38K03A01-01E Sep.01,2002-00
  31. 31. <A3. Fieldbus-ready Field Devices> A3-9 Features of Control Valves with the Fieldbus Communication • Improvement of valve controllability (detects stroke cycle, open-close time, etc. to predict clogging, sticking, leakage, etc.) • Remote monitoring of control valves • Modification and improvement of valve characteristics • Stabilized control together with operability and complete closure of valves • Improved valve stability • Ease-to-operate adjustment and stabilization of valve characteristics • Reduction of valve accessories The following figure shows the compensation curves of valve flow characteristics. By using the control valve with the Fieldbus communication, the following valve flow characteristics will be change easily. In addition, it is possible to adopt the customized characteristics. Intrinsic flow characteristics (from ISA Hand Book of Control Valve) t en oo er k op r ua Sq Quic r nea Li t cen per ual Eq lic rbo pe Hy Flow rate Valve opening A030201E.EPS Figure Modification of Valve Flow Characteristics TI 38K03A01-01E Sep.01,2002-00
  32. 32. <A3. Fieldbus-ready Field Devices> A3-10 A3.3 Using Self-diagnostics Function The Fieldbus communication system can predict a problem in a field device using the self- diagnostics function. Integration of Instrumentation and Self-diagnostics Functions The conventional analog transmission system can handle only one signal on a single cable. The system handles the PV or MV value and the self-diagnostics information as completely different data, even if it is information from the same field device. The Fieldbus communication system can handle multiple signals on a single cable. The system can handle the PV or MV value and the self-diagnostics information in the same environment. Instrumentation and self-diagnostics will be performed under the same environment by integrating work in the field into a single network. This idea is far different from the conventional one which has separated instrumentation from self-diagnostics. Problem Prediction Function Since Fieldbus handles the measured values in engineering units, it allows the system to accurately measure slight changes in pressure and temperature, other than the PV value. This enables the system to detect the symptoms of problems that were difficult to predict. For example, suppose the system cannot judge whether the self-diagnostics result of a field device is abnormal or normal. The conventional analog transmission system can transmit a self-diagnostics result as either abnormal or normal. Therefore, if a result cannot be judged as being abnormal or normal, the system always handles it as abnormal for safety. If a minor abnormality is generated in field devices, a number of alarms will be displayed on the panel in the control room. However, if minor abnormalities in field devices are handled as normal to reduce alarms in the control room, the symptom of a major problem may not be detected. If a self-diagnostics result cannot be judged as abnormal or normal, Fieldbus communica- tion system can transmit the status information to the system. In addition, Fieldbus com- munication system will be able to monitor the information which influences measurement and control, such as clogging, vibration, etc. The use of this information allows the system to chronologically analyze changes in field devices and predict their problems. Using the dedicated package software will make the maintenance work easier. TI 38K03A01-01E Sep.01,2002-00
  33. 33. <A3. Fieldbus-ready Field Devices> A3-11 A3.4 Yokogawa’s Fieldbus-ready Field Devices Line- up Differential Pressure/Pressure Transmitter DPharp EJA Series (suffix code for output: F) Function Block: Two (2) AI function blocks One (1) PID function block (option: /LC1) Link Master function (option: /LC1) Hazardous area certification for FM, CENELEC, CSA, or JIS is available. FISCO model for FM or CENELEC intrinsically safe is also available. (See GS 01C22T02-00E for the detail.) Vortex Flowmeter YF100 (YEWFLO*E) (suffix code for output: F) Function Block: One (1) AI function block One (1) PID function block (option: /LC1) Link Master function (option: /LC1) (See GS 01F02F04-00E for the detail.) Magnetic Flowmeter ADMAG AE (with option code /FB) Function Block: One (1) AI function block One (1) PID function block (option: /LC1) Link Master function (option: /LC1) Hazardous area certification for CENELEC ATEX is available. (See GS 01E07F01-00E for the detail.) Temperature Transmitter YTA320 (suffix code for output: F) Function Block: Four (4) AI function blocks One or two (1 or 2) PID function block(s) (option: /LC1 or /LC2) Link Master function: with one (1) PID function block (option: /LC1) with two (2) PID function blocks (option: /LC2) Hazardous area certification for FM, CENELEC, CSA, SAA, or JIS is available. FISCO model for CENELEC intrinsically safe is also available. (See GS 01C50T02-00E for the detail.) TI 38K03A01-01E Sep.01,2002-00
  34. 34. <A3. Fieldbus-ready Field Devices> A3-12 Advanced Valve Positioner YVP110 Function Block: One (1) AO function block Two (2) DI function block One (1) OS (Output Splitter) function block One (1) PID function block (option: /LC1) Link Master function (option: /LC1) Signature Function:(option: /BP) Hazardous area certification for FM, CENELEC, CSA, or JIS is available. FISCO model for FM or CENELEC intrinsically safe is also available. (See GS 21B04C01-01E for the detail.) YVP Management Software <Model: YVP20S> This software package offers a variety of functions to help users to easily set up and tune YVP110. This software needs National Instruments FBUS fieldbus communication interface card. (See GS 21B04C50-01E for the detail.) Paperless Digital Recorder DAQSTATION (with option code /CF1) Function Block: Eight (8) AI function block (1-channel each) One (1) MAO function block (8-channel) Link Master function (See GS 04L01A01-00E for the detail.) TI 38K03A01-01E Sep.01,2002-00
  35. 35. <A4. Yokogawa’s Fieldbus-ready Systems> A4-1 A4. Yokogawa’s Fieldbus-ready Systems The control system that uses Fieldbus communication handles more advanced information than the conventional analog transmission system. Information recep- tion, display and record management are more important factors in control systems. This section describes the Yokogawa systems that support Fieldbus. The “H1 Fieldbus Communication Protocol” and “H1 Fieldbus” indicated in this section and Part B are the “FOUNDATION Fieldbus H1 (Low Speed Voltage Mode)” of the Fieldbus Foundation. A4.1 Fieldbus Support in Yokogawa’s CENTUM Control Systems The CENTUM CS 3000 Integrated Production Control System, CENTUM CS 1000 Produc- tion Control System, and CENTUM CS Integrated Production Control System support Fieldbus. This section describes a typical system configuration for each CENTUM Fieldbus system. These systems are connected to field devices via I/O modules which support 1-5 V DC/4- 20 mA I/Os, thermocouple and resistance temperature detector inputs, digital I/O, and communication. The Fieldbus Communication Module can also be combined with such conventional analog I/O modules. TI 38K03A01-01E Sep.01,2002-00
  36. 36. <A4. Yokogawa’s Fieldbus-ready Systems> A4-2 A4.1.1 Fieldbus Support in FCS for FIO of CENTUM CS 3000 Fieldbus support in FCS for FIO of CENTUM CS 3000 is shown below. FCS for FIO can be connected via an ALF111 Fieldbus Communication Module installed in a node unit to FF transmitters and FF valve positioners. Operation and Ethernet monitoring function Engineering function (system generation) HIS PRM Fieldbus tools: • Engineering tool • Device management tool V net FCS FCU ESB bus EB401 SB401 ALF111 ALF111 (dual (dual IS barrier or (in service) (stand-by) redundant) redundant) lightning arrester (optional) H1 fieldbus segment Local Node Terminator Terminator (optional) Fieldbus ER bus power supply unit (optional) ACB41 EB501 ALF111 ALF111 (dual IS barrier or (in service) (stand-by) redundant) lightning arrester (optional) H1 fieldbus segment Remote Node Terminator Terminator (optional) Fieldbus power supply unit (optional) HIS: Human Interface station PRM: Plant Resource Manager FCS: Field control station FCU: Field control unit SB401: ESB-bus interface (in Local Node) EB401: ER-bus interface (in Local Node) EB501: ER-bus interface (in Remote Node) ALF111: Foundation Fieldbus communication module ACB41: I/O expansion cabinet for FIO A040101E.EPS Figure Fieldbus Support in FCS for FIO of CENTUM CS 3000 TI 38K03A01-01E Sep.01,2002-00
  37. 37. <A4. Yokogawa’s Fieldbus-ready Systems> A4-3 ALF111 Fieldbus Communication Module Specifications Number of ALF111s per FCS: Standard FCS control function: Max. 16 (*1) modules (8 pairs for a dual- redundant configuration) per FCS Enhanced FCS control function: Max. 32 (*2) modules (16 pairs for a dual- redundant configuration) per FCS Number of ALF111 ports: Max. 4 ports per ALF111 (One port is connected to one segment (*3).) Number of field devices per segment (*3): Max. 32 units per segment (including an ALF111 as one unit) Number of FF faceplate blocks: Max. 250 blocks for Standard FCS (general- purpose database) Max. 600 blocks for Enhanced FCS (general- purpose database) ALF111 dual-redundant support: Dual-redundant configuration possible with two adjacent ALF111s in a node Link active scheduler (LAS) function: Available Time master function: Available The number of field devices per segment varies significantly depending on the cable length, power supply capacity, existence of a barrier, etc. For details, refer to Section B2.2 of Part B. Other Fieldbus specifications are in accordance with the specifications for the FOUNDA- TION Fieldbus. *1: For the standard FCS control function, the maximum number of ALF111s may be two depending on the database type selected as the FCS database. For details, refer to GS, “Control Function for Standard Field Control Station (for FIO)” (GS 33Q03K30-31E). *2: For the enhanced FCS control function, when “remote node expanded” is selected as the database type, the maximum number of ALF111s is 32. In the other database type, the maximum number of ALF111s is 16. For details, refer to GS, “Control Function for Enhanced Field Control Station (for FIO)” (GS 33Q03K31-31E). *3: A segment is an engineering unit consisting of several Fieldbus devices and ALF111 port to be connected to one H1 Fieldbus. SEE ALSO For details of the ALF111 Fieldbus Communication Module, refer to GS 33Q03L60-31E. TI 38K03A01-01E Sep.01,2002-00
  38. 38. <A4. Yokogawa’s Fieldbus-ready Systems> A4-4 A4.1.2 Fieldbus Support in FCS for RIO and Compact FCS of CENTUM CS 3000 Fieldbus support in FCS for RIO and Compact FCS of CENTUM CS 3000 is shown below. FCS for RIO and Compact FCS can be connected via an ACF11 Fieldbus Communication Module installed in an I/O module nest to FF transmitters and FF valve positioners. Operation and Ethernet monitoring function Engineering function (system generation) HIS PRM Fieldbus tools: • Engineering tool • Device management tool V net LFCS SFCS RIO bus NIU ACF11 ACF11 Fieldbus External power supply (optional) Intrinsic safety barrier / arrester Terminator (optional) Coupler Terminator H1 Fieldbus (optional) Coupler HIS: Human Interface Station PRM: Plant Resource Manager LFCS: Standard FCS SFCS: Compact FCS Field devices RIO bus: Remote I/O bus NIU: Node Interface Unit ACF11: Fieldbus Communication Module A040102E.EPS Figure Fieldbus Support in FCS for RIO and Compact FCS of CENTUM CS 3000 TI 38K03A01-01E Sep.01,2002-00
  39. 39. <A4. Yokogawa’s Fieldbus-ready Systems> A4-5 ACF11 Fieldbus Communication Module Specifications of CENTUM CS 3000 The main specifications of the ACF11 Fieldbus Communication Module of CENTUM CS 3000 are shown below. For LFCS (FCS for RIO) Number of ACF11s per FCS: Max. 80 modules per FCS Number of ACF11s per AMN33 nest: Max. two modules per nest Number of segments (*1) per ACF11: Max. one segment Number of field devices per segment (*1): Max. 32 units per segment (including an ACF11 as one unit) Link active scheduler (LAS) function: Available Time master function: Available Fieldbus power supply: Available (supply current: max. 80 mA) For SFCS (Compact FCS) Number of ACF11s per FCS: Max. 10 modules per FCS Number of ACF11s per AMN33 nest: Max. two modules per nest Number of segments (*1) per ACF11: Max. one segment Number of field devices per segment (*1): Max. 32 units per segment (including an ACF11 as one unit) Link active scheduler (LAS) function: Available Time master function: Available Fieldbus power supply: Available (supply current: max. 80 mA) *1: A segment is an engineering unit consisting of several Fieldbus devices and ACF11 to be connected to one H1 Fieldbus. SEE ALSO For details of the ACF11 Fieldbus Communication Module of CENTUM CS 3000, refer to GS 33Q03L50- 31E. TI 38K03A01-01E Sep.01,2002-00
  40. 40. <A4. Yokogawa’s Fieldbus-ready Systems> A4-6 A4.1.3 Fieldbus Support in CENTUM CS 1000 Fieldbus support in CENTUM CS 1000 is shown below. FCS can be connected via an ACF11 Fieldbus Communication Module installed in an I/O module nest to FF transmitters and FF valve positioners. Operation and Ethernet monitoring function Engineering function (system generation) HIS PRM Fieldbus tools: • Engineering tool • Device management tool VL net PFCS ACF11 External power supply Terminator (optional) Intrinsic safety barrier / arrester (optional) Coupler Terminator H1 Fieldbus (optional) Coupler HIS: Human Interface Station PRM: Plant Resource Manager PFCS: Control Station Field devices ACF11: Fieldbus Communication Module A040103E.EPS Figure Fieldbus Support in CENTUM CS 1000 TI 38K03A01-01E Sep.01,2002-00
  41. 41. <A4. Yokogawa’s Fieldbus-ready Systems> A4-7 ACF11 Fieldbus Communication Module Specifications of CENTUM CS 1000 The main specifications of the ACF11 Fieldbus Communication Module of CENTUM CS 1000 are shown below. Number of ACF11s per FCS: Max. 10 modules per FCS Number of ACF11s per AMN33 nest: Max. two modules per nest Number of segments (*1) per ACF11: Max. one segment Number of field devices per segment (*1): Max. 32 units per segment (including an ACF11 as one unit) Link active scheduler (LAS) function: Available Time master function: Available Fieldbus power supply: Available (supply current: max. 80 mA) *1: A segment is an engineering unit consisting of several Fieldbus devices and ACF11 to be connected to one H1 Fieldbus. SEE ALSO For details of the ACF11 Fieldbus Communication Module of CENTUM CS 1000, refer to GS 33S03L50- 31E. TI 38K03A01-01E Sep.01,2002-00
  42. 42. <A4. Yokogawa’s Fieldbus-ready Systems> A4-8 A4.1.4 Fieldbus Support in CENTUM CS Fieldbus support in CENTUM CS is shown below. FCS can be connected via an ACF11 Fieldbus Communication Module installed in an I/O module nest to FF transmitter and FF valve positioners. Operation and monitoring function System generation function Fieldbus tools PC • Engineering tool ICS EWS • Device Management tool Ethernet ACG V net FCS FCU RIO bus NIU ACF11 External power supply Terminator (optional) Intrinsic safety barrier / arrester (optional) Coupler H1 Fieldbus Terminator (optional) Coupler ICS: Information and Command Station ACG: Communication Gateway Unit FCS: Field Control Station FCU: Field Control Unit Field devices RIO bus: Remote I/O bus NIU: Node Interface Unit ACF11: Fieldbus Communication Module A040104E.EPS Figure Fieldbus Support in CENTUM CS TI 38K03A01-01E Sep.01,2002-00
  43. 43. <A4. Yokogawa’s Fieldbus-ready Systems> A4-9 ACF11 Fieldbus Communication Module Specifications of CENTUM CS The main specifications of the ACF11 Fieldbus Communication Module of CENTUM CS are shown below. Number of ACF11s per FCS: Max. 80 modules per FCS Number of ACF11s per AMN33 nest: Max. two modules per nest Number of segments (*1) per ACF11: Max. one segment Number of field devices per segment (*1): Max. 32 units per segment (including an ACF11 as one unit) Link active scheduler (LAS) function: Available Time master function: Available Fieldbus power supply: Available (supply current: max. 80 mA) *1: A segment is an engineering unit consisting of several Fieldbus devices and ACF11 to be connected to one H1 Fieldbus. SEE ALSO For details of the ACF11 Fieldbus Communication Module of CENTUM CS, refer to GS 33G6K40-01E. TI 38K03A01-01E Sep.01,2002-00
  44. 44. <A4. Yokogawa’s Fieldbus-ready Systems> A4-10 A4.2 Connection of FF Devices from Other Vendors to Yokogawa’s CENTUM Control Systems FF devices from other vendors can be connected to CENTUM under the following condi- tions: Use devices registered by the Fieldbus Foundation The Fieldbus Foundation prescribes the interoperability test procedure called Interoperability Test (IT) to ensure interoperability between the FF devices. The FF devices that passed the IT are registered to the Foundation, and information about them is pub- lished on the Fieldbus Foundation’s web site (http://www.fieldbus.org/). The field devices from other vendors, which are registered to Fieldbus Foundation, can be connected to CENTUM. Yokogawa recommends to use the IT4.0 (or later version) registra- tion devices including the Capabilities File and Device Description (DD) File. For the Fieldbus accessories (e.g. cables, external bus power supply units, barriers, and arresters), there is no system of registering to the Fieldbus Foundation; these accessories should be used according to the conditions provided by their vendors. Yokogawa informs users of field-proven Fieldbus accessories as recommended devices. Contact Yokogawa sales for the Fieldbus accessories if necessary. Use devices as instructed Use devices according to the conditions provided by their vendors. The vendors assume responsibility for the quality, performance and warranty of their field devices. Test devices A user who uses field devices from other vendors is responsible for testing them. Yokogawa, if required, will provide assessment information on connecting other vendors’ devices to CENTUM, to assist users in device selection. Yokogawa supports only standard Fieldbus specifications, not manufac- turer-specific extensions Yokogawa’s systems support information and functions that meet the standard specifica- tions prescribed by the Fieldbus Foundation. They may not support another manufacturer’s proprietary functions. The Fieldbus standardization facilitates operation and maintenance of field devices from different manufacturers. Yokogawa can meet a variety of user needs, including startup and maintenance work on process control systems including products (components) from other vendors, based on accumulated know-how about devices and their usage. TI 38K03A01-01E Sep.01,2002-00
  45. 45. <Int> <Ind> <Rev> Toc B -1 Fieldbus Technical Information Part B Fieldbus Engineering TI 38K03A01-01E 3rd Edition CONTENTS B1. Managing Fieldbus Engineering .......................................................... B1-1 B1.1 Fieldbus Engineering Process ..................................................................... B1-1 B1.2 Difference between Fieldbus and Analog Signal Process Control Systems ......................................................................................................... B1-4 B1.3 Software Packages for Fieldbus .................................................................. B1-5 B2. System Design Considerations ........................................................... B2-1 B2.1 Considerations in Basic and Overall Design ............................................... B2-2 B2.2 Detail Design Considerations ...................................................................... B2-3 B2.2.1 Investigation of Number of Field Devices connected to an H1 Segment ............................................................................... B2-4 B2.2.2 Selection of Fieldbus Cable and Wiring Method .............................. B2-5 B2.2.3 Design of FF Device Grouping per Segment ................................... B2-8 B2.2.4 Expansion and Modification of Existing System .............................. B2-8 B3. System Construction Considerations ................................................. B3-1 B3.1 New Construction of Fieldbus Process Control System ............................ B3-1 B3.1.1 Mounting Terminators ..................................................................... B3-3 B3.1.2 Mounting Couplers ......................................................................... B3-3 B3.1.3 Cabling ........................................................................................... B3-4 B3.1.4 Installing an Intrinsic Safety Barrier ................................................. B3-4 B3.1.5 Handling the Shield Mesh ............................................................... B3-4 B3.1.6 Connecting the Fieldbus Cable and Handling the Shield Mesh for Fieldbus Communication Module .................................................... B3-4 B3.2 Reusing Existing Cables .............................................................................. B3-5 B4. System Startup Considerations ........................................................... B4-1 B4.1 Tool Necessary for Startup ........................................................................... B4-1 B4.2 Technologies and Expertise Necessary for Startup ................................... B4-2 B4.3 Labor Savings in Startup Work .................................................................... B4-3 B5. System Maintenance Considerations .................................................. B5-1 B5.1 Daily Maintenance ......................................................................................... B5-1 B5.2 Inspection and Maintenance ........................................................................ B5-2 B5.3 Maintenance Management (Maintenance Plan, Device Management, Audit Trail) ..................................................................................................... B5-3 B5.4 Evolution of Maintenance ............................................................................. B5-3 TI 38K03A01-01E Sep.01,2002-00
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