General purpose field communication system

Published in English only * Corrigendum to EN issued August 2002 * Superseded by EN 61158-2:2004 to EN 61158-6:2004 and EN 61784-1:2004

General purpose field communication system - Amendment A1/Note: Includes Corrigendum of August 2002

General Information

Status
Withdrawn
Publication Date
14-May-2002
Technical Committee
Drafting Committee
Parallel Committee
Current Stage
6060 - Document made available
Start Date
15-May-2002
Completion Date
15-May-2002

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SLOVENSKI STANDARD
SIST EN 50170:2001/A1:2003
01-december-2003
General purpose field communication system - Amendment A1/Note: Includes
Corrigendum of August 2002
General purpose field communication system
Ta slovenski standard je istoveten z: EN 50170:1996/A1:2002
ICS:
35.100.01 Medsebojno povezovanje Open systems
odprtih sistemov na splošno interconnection in general
35.200 Vmesniška in povezovalna Interface and interconnection
oprema equipment
SIST EN 50170:2001/A1:2003 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 50170:2001/A1:2003
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SIST EN 50170:2001/A1:2003
EUROPEAN STANDARD EN 50170/A1
NORME EUROPÉENNE Volume 4
EUROPÄISCHE NORM May 2002
ICS 35.100.00; 35.200
English version
General purpose field communication system

This amendment A1 modifies the European Standard EN 50170:1996; it was approved by CENELEC on

2000-04-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations

which stipulate the conditions for giving this amendment the status of a national standard without any

alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on

application to the Central Secretariat or to any CENELEC member.

This amendment exists in one official version (English). A version in any other language made by

translation under the responsibility of a CENELEC member into its own language and notified to the

Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,

Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands,

Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 50170:1996/A1:2002 E
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SIST EN 50170:2001/A1:2003
Page 2
EN 50170-0-1:1996/A1:2002
Foreword
This amendment has been prepared by the British National Committee following
acceptance by technical committee CLC/TC 65CX Fieldbus at its meeting in London
on 1996-09-27 that the British Pre-standard DD 238:1996 Fieldbus met the
candidate criteria for inclusion within EN 50170 (see the paragraph headed
‘Solutions’ in clause 2.1 of EN 50170-0-1:1996).
The amendment is limited to:
� necessary editorial alterations to the published text
� new text relating to the inclusion (as A1 Volume 4) of BSI DD 238.
The following changes were made as a result of comments submitted during the
first (1997) UAP ballot:
� References to unpublished documents (for example to IEC 61158-2/Amendment 3)
have been replaced by the appropriate texts.
� References to IEC 61158 Application Layer CDV drafts have been replaced by
references to the resulting IEC Technical Specifications. For completeness,
the TSs have been included as Parts 8 and 9.
� Where appropriate cross-references to IEC 61158 have been made more precise.
The text of the draft was submitted to the formal vote and was approved by
CENELEC as amendment A1 to EN 50170:1996 on 2000-04-01.
The following dates were fixed:
(dop) 2002-11-01
� latest date by which the amendment has to be implemented
at a national level by the publication of an identical
national standard or by endorsement
(dow) 2003-04-01
� latest date by which the national standards conflicting
with the amendment have to be withdrawn
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SIST EN 50170:2001/A1:2003
Page 3
EN 50170-0-1:1996/A1-0-1:2002
Structure of the document and overall table of contents
In paragraph 1, lines 1 and 3, delete ‘three’ and substitute ‘four’.
In paragraph 1, lines 3 and 4, delete ‘P-NET, PROFIBUS and WorldFIP’ and
substitute ‘P-NET, PROFIBUS, WorldFIP and DD 238 Foundation Fieldbus’.
In paragraph 2, line 2, delete ‘three’ and substitute ‘four’.
Add, after the list of the contents of volume 3, the following text.
‘A1 Volume 4 contains:
Part 1-4 (Informative) General description of EN 50170/A1 Volume 4
(DD 238 Foundation Fieldbus)
Part 2-4 Physical layer specification and service definitions
Part 3-4 Data link layer service definitions
Part 4-4 Data link layer protocol specifications
Part 5-4 Application layer service definitions
Part 6-4 Application layer protocol specifications
Part 7-4 Network management
Sub-part 7.1-4 System Management
Sub-part 7.2-4 Network Management’
Part 8-4 IEC/TS 61158-3:1999 Data Link layer service definition
Part 9-4 IEC/TS 61158-4:1999 Data Link layer protocol specification
Foreword
Current situation in the European market
In paragraph 4, line 1, delete ‘three’ and substitute ‘four’.
EN 50170 objective
In paragraph 1, indent 2, line 1, delete ‘three’ and substitute ‘four’.
Usage of EN 50170
Delete paragraph 1 entirely and substitute the following new paragraph.
‘According to the history and the decision of TC 65CX neither to develop any new
compromise nor to re-write the actual concepts on the market, the reader should
pay his dedicated
ATTENTION
to the following notes:
-”EN 50170 contains the four following different specifications, without
attempting to develop any compromise or to mix them, as per the PAS
principles:
EN 50170 volume 1 (based on and technically identical to DK 502058
and DK 502066)
EN 50170 volume 2 (based on and technically identical to DIN 19245
series
EN 50170 volume 3 (based on and technically identical to NF C 46602,
NF C 46603, NF C 46605, NF C 46606, NF C 46606/A1, NF C 46607,
NF C 46607/A1, EN 61158-2)
EN 50170/A1 volume 4 (based on and technically identical to BSI
DD 238 series, EN 61158-2, IEC/FDIS 61158-3, IEC/FDIS 61158-4)
The concepts of these four specifications are different. For each
implementation, the user has to select the volume of EN 50170 which suits
the user’s application needs.’
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SIST EN 50170:2001/A1:2003
Page 4
EN 50170-0-1:1996/A1:2002
Part 0-1 Introduction
Contents
Add the title of clause 6 as follows:
‘6 MAIN FEATURES OF EN 50170/A1 VOLUME 4 (DD 238 FOUNDATION FIELDBUS)’
5 Main features of EN 50170, Volume 3 (WorldFIP)
Add, at the end of clause 5, the following new clause 6.
‘6 Main features of EN 50170/A1 Volume 4 (DD 238 Foundation Fieldbus)
EN 50170/A1 Volume 4 (DD 238) has been originally developed by the Fieldbus
Foundation, an open organisation supported by a world-wide consensus of industry
suppliers for process control equipment and factory automation equipment.
Responding to strong international user demand, the Foundation has based its
specifications on the work of the IEC, and Foundation members also contribute to
the IEC committee work.
Following strong requests from user companies in UK, BSI has adopted the
Fieldbus Foundation specifications as DD 238 and made it available to CENELEC.
Technically the DD 238 Foundation Fieldbus specification is based on published
and draft international standards prepared by the IEC Fieldbus committee
IEC/SC 65C.
EN 50170/A1 Volume 4 has been published as a British pre-standard (known as
DD 238 Fieldbus) in 8 parts comprising the following main features:
DD 238: Part 1:1996 is an informative Introductory Guide to System Architecture.
It describes how the components specified in other parts of DD 238 may be
related and configured to construct and support DD 238 Fieldbus devices,
Networks and Systems. It is technically equivalent to Fieldbus Foundation
specification FF-800 revision 1.3
DD 238: Part 2:1996 is a Physical Layer profile using the EN 61158-2
specification for 31,25 kbit/s operation. Features of particular importance
are:
� Power can be supplied directly to field devices through the bus signal
conductors.
� Intrinsically safe (IS) fieldbus applications can be supported using bus
powered devices and IS barriers.
� Wiring installed for 4-20 mA devices may also be used for the DD 238
Foundation Fieldbus.
Part 2 is technically equivalent to Fieldbus Foundation specification
FF 816 revision 1.3
DD 238: Part 3:1996 is a Data Link Services Specification using the
IEC/FDIS 61158-3. It is technically equivalent to Fieldbus Foundation
specification FF-821 revision 1.3
DD 238: Part 4:1996 is a Data Link Protocol Specification using the
IEC/FDIS 61158-4. It is technically equivalent to Fieldbus Foundation
specification FF-822 revision 1.3
The IEC data link specification has been chosen because it combines the best
features of other existing protocols and adds a number of important new service
features to support modern application requirements. These include:
� An integrated access control method combining the token passing approach of
PROFIBUS (volume 2), and the time-critical approach of WorldFIP (volume 3)
with migration paths from existing applications using these protocols.
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SIST EN 50170:2001/A1:2003
Page 5
EN 50170-0-1:1996/A1-0-1:2002
� Services needed to support multiple data models with particular features
for Client/Server, Publisher/Subscriber and Report Distributor as
implemented in DD 238: Part 5.
� Multi-segment addressing to support small and large networks assembled from
multiple DD 238 fieldbus segments.
� Tools for accurate time distribution and synchronisation across
multi-segment systems.
� Automatic backup capability to continue schedule operation if the current
bus master fails.
� On line support for flexible and time critical scheduling including
construction and revision.
� On line support for device detection, recognition and configuration.
DD 238: Part 5:1996 is a Fieldbus Access Sub-layer building on IEC data link
services to provide the needed data models for modern automation systems.
� Client/Server. This is the model used by pairs of application entities
using one-to-one communications, for example, a traditional master station
issuing confirmed requests and commands to a slave.
� Publisher/Subscriber. This is the model to support efficient simultaneous
transfer of data from one data-source (publisher) to multiple data-sinks
(subscribers) using retentive buffers.
� Report Distributor. This model supports multi-cast (one source to many
sinks) queued and prioritised communication for efficient transfer of
messages and data without immediate confirmation.
Part 5 is technically equivalent to Fieldbus Foundation specification
FF-875 revision 1.3
DD 238: Part 6:1996 is a Foundation Fieldbus Message Specification (FFMS)
defining communication objects and standard services to support user
applications such as function blocks. The main service categories include
Context Management, Object Dictionary, Variable Access, Event Services,
Upload/Download and Program Invocation. Messages are formatted using the
Abstract Syntax Notation ASN1.
Part 6 is technically equivalent to Fieldbus Foundation specification
FF-870 revision 1.3.
DD 238: Part 7:1996 Fieldbus Management is specified in two parts, sub-part 7.1
System Management and sub-part 7.2 Network Management, which are technically
equivalent to Fieldbus Foundation specifications FF-880 revision 1.0 and
FF-801 revision 1.3.
The System Management Kernel in each device maintains the information base for
distributed inter-operation of device applications. This includes a secure
configuration sequence at start-up with assignment of data link address based on
unique manufacturer assigned codes and user assigned tag names. Procedures are
included for recognising and supporting temporary devices such as Hand Held
Terminals and Workstations. System management also provides scheduling services
for user applications and a common application time reference among all devices
to ensure that user tasks and function blocks can execute in the proper time
relationship across the network.
The Network Management agent supports vertical integration of Fieldbus layers by
providing capabilities for configuration management, performance management and
fault management. These capabilities are accessed by the same services as other
device applications, they do not use a specialised management protocol.’
Data Link layer
For completeness, the following documents are included as Parts 8 and 9
respectively:
IEC/TS 61158-3:1999 Digital data communications for measurement and control -
Fieldbus for use in industrial control systems - Part 3: Data link service
definition.
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SIST EN 50170:2001/A1:2003
Page 6
EN 50170-0-1:1996/A1:2002
IEC/TS 61158-4:1999 Digital data communications for measurement and control -
Fieldbus for use in industrial control systems - Part 4: Data link protocol
specification’
Volume 3
Add, at the end of volume 3, the following new A1 volume 4.
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SIST EN 50170:2001/A1:2003
Page 7
EN 50170-0-1:1996/A1-0-1:2002
General Purpose Field Communication System
Volume 4
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SIST EN 50170:2001/A1:2003
Page 8
EN 50170-0-1:1996/A1:2002
Table of Contents of Volume 4 ..............................................Page
Part 1-4 General description of EN 50170/A1 Volume 4
(DD 238/Foundation Fieldbus)........................................9
Part 2-4 Physical layer specification and service definitions...............65
Part 3-4 Data link layer service definitions...............................111
Part 4-4 Data link layer protocol specifications...........................133
Part 5-4 Application layer service definitions.............................201
Part 6-4 Application layer protocol specifications.........................275
Part 7-4 Network management
Sub-Part 7.1-4 System Management..................................401
Sub-Part 7.2-4 Network Management.................................459
Part 8-4 IEC/TS 61158-3:1999 Digital data communications for measurement and
control - Fieldbus for use in industrial control systems – Part 3:
Data link service definition......................................509
Part 9-4 IEC/TS 61158-4:1999 Digital data communications for measurement and
control - Fieldbus for use in industrial control systems – Part 4:
Data link protocol specification..................................653
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SIST EN 50170:2001/A1:2003
Page 9
EN 50170:1996/A1-1-4:2002
General Purpose Field Communication System
Part 1-4
General Description of EN 50170/A1 Volume 4
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SIST EN 50170:2001/A1:2003
Page 10
EN 50170:1996/A1-1-4:2002
Contents
Page
1 Overview.................................................................12
1.1 Key Components of Fieldbus Systems........................................13
1.1.1 Function Block Application Processes ................................13
1.1.2 Object Dictionary (OD) and Device Descriptions (DD) .................14
1.1.3 Network Communications ..............................................14
1.1.4 Network Management ..................................................15
1.1.5 System Management ...................................................16
1.2 Relationship to the ISO OSI Reference Model...............................17
1.3 Relationship to the International Electro-technical Commission (IEC)
Fieldbus Standards........................................................17
1.4 EN 50170/A1 Volume 4 Documents............................................18
2 Network Topology.........................................................18
2.1 Single Link Topology......................................................19
2.2 Bridged Networks..........................................................19
2.3 Device Architecture.......................................................21
3 Application Process (AP).................................................22
3.1 Overview..................................................................22
3.2 Network Visible Objects...................................................22
3.3 Application Layer Interface...............................................23
3.4 Object Dictionary.........................................................23
3.5 AP Directory..............................................................24
3.5.1 AP Directory Header .................................................24
3.5.2 Object References ...................................................25
3.5.3 AP Architecture Summary .............................................26
4 Function Block APs.......................................................27
4.1 Overview..................................................................27
4.2 Block Types...............................................................27
4.2.1 Resource Blocks .....................................................29
4.2.2 Transducer Blocks ...................................................29
4.2.3 Function Blocks .....................................................29
4.2.4 View and Trend Objects ..............................................29
4.2.5 Alert Objects .......................................................29
4.2.6 Link Objects ........................................................29
4.3 Types of Function Blocks..................................................30
5 System Management Kernel (SMK)...........................................30
5.1 Overview..................................................................30
5.2 SMK Communications........................................................31
5.3 SMK Services..............................................................31
5.3.1 SMIB Access .........................................................31
5.3.2 Tag and Address Assignment ..........................................31
5.3.3 Device Identification ...............................................33
5.3.4 Locating Remote Devices and Objects .................................33
5.3.5 Clock Synchronization ...............................................33
5.3.6 Function Block Scheduling ...........................................34
6 Communications Entity....................................................34
6.1 Overview..................................................................34
6.2 Network Management Agent..................................................35
6.3 Foundation Fieldbus Messaging Service (FFMS)..............................36
6.4 Fieldbus Access Sublayer (FAS)............................................38
6.5 Data Link Layer (DLL).....................................................39
6.5.1 DLL Lower Level (Media Access) Functions ............................40
6.5.2 DLL Upper Level (Data Transfer) Functions ...........................41
6.6 Physical Layer............................................................43
7 VCR and SMKP Operation...................................................43
7.1.1 Report Distribution VCRs ............................................44
7.1.2 Publisher/Subscriber VCRs ...........................................46
7.1.3 Client/Server VCRs ..................................................48
7.1.4 System Management Kernel Protocol (SMKP) Communications .............51
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SIST EN 50170:2001/A1:2003
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EN 50170:1996/A1-1-4:2002
8 Specification of Fieldbus Systems........................................52
8.1 Common Model..............................................................52
8.2 Device Descriptions.......................................................53
8.2.1 Device Description Language (DDL)....................................53
8.2.2 Device Description Services..........................................54
8.3 Communications Profiles...................................................55
8.3.1 Passive Devices......................................................55
8.3.2 Remote Input/Output (I/O) Devices....................................55
8.3.3 Temporary Devices....................................................56
8.3.4 Field Devices........................................................56
8.3.5 Display and Control Devices..........................................56
9 Configuration Information................................................56
9.1 Level 1 Configuration: Manufacturer Device Definition.....................56
9.2 Level 2 Configuration: Network Definition.................................57
9.3 Level 3 Configuration: Distributed Application Definition.................58
9.4 Level 4 Configuration: Device Configuration...............................59
10 System Configuration and Startup.........................................60
10.1 Offline Configuration....................................................60
10.2 Link and System Startup..................................................60
10.3 LAS Schedule Loading.....................................................61
10.4 Configuration Updates....................................................61
Annex A (informative) Standard Data Types and Data Structures................62
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SIST EN 50170:2001/A1:2003
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EN 50170:1996/A1-1-4:2002
General information on licensing
CENELEC calls attention to the fact that patent rights are linked to EN 50170
Amendment 1 (Foundation Fieldbus). CENELEC takes no position concerning the
evidence, validity and scope of this patent right. The following release of
rights was made available to CENELEC. This release of rights for EN 50170/A1
contains the following statement (extract):
“… Rosemount Inc. is willing to grant licenses under fair, reasonable and non-
discriminatory terms to the invention claimed und Unites States patent number
5,76489 and corresponding foreign patents for purposes of implementing products
that are compliant with EN 50170/A1. …”
Rosemount’s letter and Fieldbus Foundation’s undertakings (policy letter on
licensing) in this respect are on file with CENELEC and available for inspection
by all interested parties at the CENELEC Central Secretariat.
The license details may be obtained from:
Fisher-Rosemount European Headquarters AG
Blegistrasse 21
CH-6341 Baar
Switzerland

If during the application of this Standard Intellectual Property Rights may appear

and will not be made available on reasonable and non discriminatory terms and
conditions to anyone wishing to obtain such a license, applying the rules of
CEN/CENELEC Memorandum 8, this fact shall be brought to the attention of CENELEC
Central Secretariat for further action.
0 Scope
This document is an informative description of the architecture of the
EN 50170/A1 Volume 4 Fieldbus. It describes how the components specified in the
other Parts of EN 50170/A1 Volume 4 may be related and configured to construct
and support EN 50170/A1 Volume 4 Fieldbus devices, networks, and systems.
1 Overview
A fieldbus system is a distributed system composed of field devices and
control/monitoring equipment integrated into the physical environment of a plant
or factory. Fieldbus devices work together to provide I/O and control for
automated processes and operations. Fieldbus systems may operate in
manufacturing and process control environments that include intrinsic safety
requirements. In these environments, devices operate with limited memory and
processing power and with networks that have low bandwidth. The
EN 50170/A1 Volume 4 System Architecture provides a framework for describing
these systems as a collection of physical devices interconnected by a fieldbus
network. Fieldbus networks may be composed of one or more links interconnected
by bridges. Bridges transfer messages transparently between links. Communication
between physical devices and across bridges is provided by physical layer and
data link layer protocols.
Each physical device performs a portion of the total system operation by
implementing one or more application processes. Application processes perform
one or more time-critical functions, such as providing sensor readings or
implementing control algorithms. These and other elementary field device
functions are modelled as function blocks. Their activities are coordinated
through configuration of their operating parameters, execution schedules, and
communications.
NOTE Application Process (AP) is a term defined by the International Standard
“Information technology - Open systems interconnection - Basic reference model
(ISO/IEC 7498) to describe the portion of a distributed application that is

resident in a single device. The term has been adapted to the fieldbus environment

to describe entities within devices that perform a related set of functions, such

as function block processing, network management, and system management.
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SIST EN 50170:2001/A1:2003
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EN 50170:1996/A1-1-4:2002
Communication between application processes occurs through application layer
protocols. The layers between the data link layer and the application layer, as
defined by ISO/IEC 7498, are not present in the EN 50170/A1 Volume 4 System
Architecture.
1.1 Key Components of Fieldbus Systems
The EN 50170/A1 Volume 4 System Architecture is simple and open. It has been
designed to be simple and to meet the functional, environmental, and technology
needs of distributed manufacturing and process control systems. It is open so
that distributed automation systems can be constructed from control and
measurement devices manufactured by different vendors.
This architecture represents a departure from vendor specific control systems
architectures that have dominated the marketplace in the past. In these
architectures, proprietary interfaces define how devices communicate with each
other. Devices that work in one vendor’s control system, therefore, do not work
in that of another. Furthermore, because of these proprietary interfaces, the
upgrade and evolution of a system is controlled more by its vendor than by what
the industry as a whole has to offer.
The EN 50170/A1 Volume 4 System Architecture has been designed to change this.
Its purpose is to open the interface definitions to promote interoperability
between and among devices, regardless of vendor. It addresses application and
communications interfaces, and provides for network and system management. The
basic structure of this architecture is illustrated in Figure 1, followed by an
overview of its key components.

NOTE EN 50170/A1 Volume 4 specifies the communication layers, shown respectively

as PhY (EN 50170/A1-2-4), DLL (EN 50170/A1-3-4 and EN 50170/A1-4-4), FAS
(EN 50170/A1-5-4), FFMS (EN 50170/A1-6-4), and their Management components for

System Management (EN 50170/A1-7.1-4) and Network Management (EN 50170/A1-7.2-4).

The other ‘User Layer’ components are included and described as informative

material to illustrate a full integrated system based on the EN 50170/A1 Volume 4

communication specification.
System Function
Function Network Mgmt.
Mgmt. Block
OD SMIB
Block APs Agent
Kernel
Objects
FFMS FFMS FFMS LME
SMKP
FAS FAS LME
NMIB
DLL DL LME
PHY PHY LME
Figure 1 - Key Components of EN 50170/A1 Volume 4 System Architecture
1.1.1 Function Block Application Processes
Automated manufacturing and process control systems perform a variety of
functions. Because each system is different, the mix and configuration of
functions are different. Therefore, the EN 50170/A1 Volume 4 System Architecture
has been designed to support a range of functional models, each addressing a
different need.
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SIST EN 50170:2001/A1:2003
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EN 50170:1996/A1-1-4:2002
One of these models, the function block model, has been specified within the
architecture to support low level functions found in manufacturing and process
control. Function blocks model elementary field device functions, such as
analogue input (AI) functions and proportional integral derivative (PID)
functions. The function block model has been supplemented by the transducer
block model to decouple function blocks from sensor and actuator specifics.
Additional models, such as the “exchange block” model, are defined for remote
input/output and programmable devices.
The function block model provides a common structure for defining function block
inputs, outputs, algorithms and control parameters and combining them into an
Application Process that can be implemented within a single device. This
structure simplifies the identification and standardization of characteristics
that are common to function blocks.
The Fieldbus Foundation has taken a first step in the standardization of
function blocks by defining a small set of parameters used in all function
blocks called universal parameters. A second level of standardization has
occurred through the definition of a standard set of function block classes,
such as input, output, control, and calculation blocks. Each of these classes
also has a small set of parameters standardized for it.
A third level of standardization provides definitions for transducer blocks
commonly used with standard function blocks. Examples include temperature,
pressure, level, and flow transducer blocks.
This classification scheme provides for a fourth level of standardization by
allowing vendors to add their own parameters by importing and subclassing
standard classes. This approach provides for the extensibility of function block
definitions as new requirements are discovered and as technology advances.
1.1.2 Object Dictionary (OD) and Device Descriptions (DD)
Assoc
...

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