IEC 62424:2008

Representation of process control engineering - Requests in P&I diagrams and data exchange between P&ID tools and PCE-CAE tools

IEC 62424:2008 specifies how process control engineering requests are represented in a P&ID for automatic transferring data between P&ID and PCE tool and to avoid misinterpretation of graphical P&ID symbols for PCE. It also defines the exchange of process control engineering request relevant data between a process control engineering tool and a P&ID tool by means of a data transfer language (called CAEX). These provisions apply to the export/import applications of such tools. It cancels and replaces IEC/PAS 62424 published in 2005. This first edition constitutes a technical revision.

Répresentation de l'ingénierie de commande de processus - Demandes sous forme de diagrammes P&I et échange de données entre outils P&ID et outils PCE-CAE

La CEI 62424:2008 spécifie la méthode de représentation des demandes d'ingénierie de commande de processus dans un schéma de tuyauterie et d'instrumentation P&ID en vue d'un transfert automatique de données entre les outils P&ID et PCE, et de manière à prévenir toute interprétation erronée des symboles P&ID graphiques pour une application PCE. Elle définit également l'échange de données de type demandes d'ingénierie de commande de processus entre un outil d'ingénierie de commande de processus et un outil P&ID au moyen d'un langage de transfert de données (appelé CAEX). Ces dispositions s'appliquent aux fonctions exportation/importation de ces outils. Elle annule et remplace la CEI/PAS 62424 publiée en 2005. Cette première édition constitue une révision technique.

General Information

• Status: Published
• Publication Date: 11-Aug-2008
• ICS: 25.040.40 - Industrial process measurement and control
• ICS: 35.240.50 - IT applications in industry
• Technical Committee: TC 65 - Industrial-process measurement, control and automation
• Drafting Committee: WG 12 - TC 65/WG 12
• Current Stage: DELPUB - Deleted Publication
• Start Date: 15-Jul-2016
• Completion Date: 13-Feb-2026

Relations

• Replaces: IEC PAS 62424:2005 - Representation of process control engineering requests in P&I diagrams and data exchange between P&ID tools and PCE-CAE tools
• Effective Date: 05-Sep-2023
• Revised: IEC 62424:2016 - Representation of process control engineering - Requests in P&I diagrams and data exchange between P&ID tools and PCE-CAE tools
• Effective Date: 05-Sep-2023

Overview

IEC 62424:2008 - Representation of process control engineering - defines how process control engineering (PCE) requests are represented on P&ID (Piping & Instrumentation Diagrams) and how P&ID tools exchange PCE-relevant data with PCE-CAE tools. The standard specifies a neutral data transfer language (CAEX) to support reliable export/import and to avoid misinterpretation of graphical symbols during automated data transfers. IEC 62424:2008 cancels and replaces IEC/PAS 62424 (2005) and constitutes a technical revision.

Key Topics

• PCE request representation in P&ID
  • Identification and representation principles for PCE requests and PCE loops
  • Types of lines, local vs. central operator interfaces, device information
  • Classification of PCE categories, processing functions, alarms, switches, safety/GMP/quality relevance
• Neutral data exchange using CAEX
  • Formal mapping of P&ID elements to a CAEX system description model
  • Modeling PCE-relevant data, external interfaces, direct and indirect links between plant hierarchy items
  • CAEX data model, full XML schema, and modeling examples (normative Annexes)
• Technical requirements
  • Rules for reference designation schemes and typical/vendor identification
  • Definition of PCE loops, attributes relevant for automatic transfer, and data handling requirements

Applications

IEC 62424 is practical for organizations and roles that require accurate, automated transfer of engineering information between P&ID authoring tools and process control engineering (PCE) CAE tools:

• Process control engineers mapping control requirements from P&ID into control system designs
• Instrument & control engineers ensuring alarms, switching logic and operator interfaces are correctly transferred
• P&ID and PCE tool vendors implementing export/import functions and CAEX support
• Plant engineering and EPC firms aiming to reduce errors in handover from design to control engineering
• Integration teams working on toolchains to support consistent digital engineering data exchange

Benefits include reduced manual rework, fewer misinterpretations of P&ID symbols in control engineering, and consistent handling of safety-, GMP- and quality-relevant control requests.

Related Standards

• Replaces IEC/PAS 62424 (2005). (For full system-level context, consult the IEC catalog for other related electrotechnical and control engineering standards.)

Keywords: IEC 62424, P&ID, PCE, CAEX, data exchange, process control engineering, PCE-CAE tools, neutral data transfer, P&ID tools.

Standards Content (Sample)

IEC 62424
Edition 1.0 2008-08
INTERNATIONAL
STANDARD
Representation of process control engineering – Requests in P&I diagrams and
data exchange between P&ID tools and PCE-CAE tools

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IEC 62424
Edition 1.0 2008-08
INTERNATIONAL
STANDARD
Representation of process control engineering – Requests in P&I diagrams and
data exchange between P&ID tools and PCE-CAE tools

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XF
ICS 35.240.50; 25.040.40 ISBN 2-8318-9942-7
– 2 – 62424 © IEC:2008(E)
CONTENTS
FOREWORD.6
INTRODUCTION.8
1 Scope.10
2 Normative references .10
3 Terms and definitions .10
4 Abbreviations .14
5 Conformity.15
6 Representation of PCE requests in a P&ID .16
6.1 PCE request and PCE loop .16
6.2 Objectives and principles .17
6.3 Requirements for the identification and representation of PCE requests .17
6.3.1 General .17
6.3.2 Types of lines .18
6.3.3 Displaying the location of the operator interface .18
6.3.4 PCE categories and processing functions .19
6.3.5 PCE request reference designation scheme .22
6.3.6 PU-vendor and typical identification.23
6.3.7 Device information.23
6.3.8 Alarming, switching and indicating.24
6.3.9 Safety-relevant, GMP and quality-relevant PCE requests .24
6.3.10 PCE control functions .25
7 Neutral data exchange of PCE relevant P&ID information.26
7.1 Objectives .26
7.2 Meaning of P&ID elements .26
7.3 PCE relevant information of P&ID tools .27
7.4 Formal description of PCE relevant information of P&ID tools.28
7.4.1 General .28
7.4.2 Modeling PCE relevant information using the CAEX system
description language .29
7.4.3 Basic CAEX mappings.29
7.4.4 Mapping of a PCE request interface to an external interface of the
corresponding plant hierarchy item .31
7.4.5 CAEX description of direct links between PCE request interfaces of
different plant hierarchy items .33
7.4.6 PCE loops .34
8 Additional PCE attributes.35
Annex A (normative) CAEX – Data model for machine information exchange.36
Annex B (informative) Examples of PCE requests.109
Annex C (normative) Full XML schema of the CAEX Model.119
Annex D (informative) CAEX modelling examples .128
Bibliography.135

Figure 1 – Information flow between P&ID and PCE tool .9
Figure 2 – Organization of PCE requests .17
Figure 3 – General representation of a PCE-Request in a P&ID.18

62424 © IEC:2008(E) – 3 –
Figure 4 – Multi-sensor element.18
Figure 5 – Local interface .19
Figure 6 – Manually operated switch in local control panel.19
Figure 7 – Pressure indication in central control room.19
Figure 8 – Example of PCE request identification .23
Figure 9 – Example of flow measurement with indication in the CCR delivered by
vendor A specified by typical A20 .23
Figure 10 – Example of pH-measurement with indication in the CCR .23
Figure 11 – Example of flow measurement with indication in the CCR and high and
low alarm .24
Figure 12 – Flow measurement with indication in the CCR and high alarm and a high-
high switching function.24
Figure 13 – Flow measurement with indication in the CCR and a high-high switch limit,
a high alarm, a low alarm and a low-low switch limit for a safety function.24
Figure 14 – GMP relevant, safety relevant and quality relevant flow measurement with
indication in the CCR .25
Figure 15 – Control function.25
Figure 16 – Safety relevant control function .25
Figure 17 – P&ID elements and associations (PCE relevant items are shown in dark
lines) .27
Figure 18 – Process data model (PCE relevant items are shown in dark lines).28
Figure 19 – PCE request data model .30
Figure 20 – Example of two plant sections and a signal connection via external
interfaces.32
Figure 21 – Simplified CAEX model of indirect links between PCE requests across
different plant hierarchy items.32
Figure 22 – Example of two plant sections and a direct connection .33
Figure 23 – Simplified CAEX model of direct links between PCE requests across
different plant hierarchy items.34
Figure A.1 – CAEX architecture of a SystemUnitClass .42
Figure A.2 – Example of a SystemUnitClassLib.42
Figure A.3 – Examples of Attributes .44
Figure A.4 – Examples of an InterfaceClassLib .46
Figure A.5 – Usage of Links.47
Figure A.6 – Example of a RoleClassLib .48
Figure A.7 – CAEX Role Concept.50
Figure A.8 – CAEX data definition for use case 1.50
Figure A.9 – CAEX data definition for use case 2.51
Figure A.10 – CAEX data definition for use case 3.51
Figure A.11 – CAEX data definition of a MappingObject.53
Figure A.12 – Example for a hierarchical plant structure .53
Figure A.13 – CAEX data structure .54
Figure A.14 – Distribution of data in several CAEX files .54
Figure A.15 – Referencing of external CAEX files .54
Figure A.16 – Example of how to use alias names .55
Figure A.17 – Multiple crossed structures .56

– 4 – 62424 © IEC:2008(E)
Figure B.1 – Local level indication, 1 process connection .109
Figure B.2 – Local level indication, 2 process connections.109
Figure B.3 – Local flow indication .109
Figure B.4 – Local pressure indication .109
Figure B.5 – Local temperature indication .109
Figure B.6 – Local control panel, pressure indication, high alarm.110
Figure B.7 – Local temperature indication, CCR temperature high alarm.110
Figure B.8 – Local pressure indication, CCR pressure high alarm and switch.110
Figure B.9 – CCR flow indication, device information: Orifice Plate.110
Figure B.10 – CCR pressure indication, low, low low and high alarm .110
Figure B.11 – CCR temperature indication and registration.111
Figure B.12 – CCR level indication and registration, 1 process connection .111
Figure B.13 – CCR level indication, 2 process connections.111
Figure B.14 – Two flow indications and flow ratio control in CCR .111
Figure B.15 – CCR flow indication and high alarm, flow control, control valve with extra
interlock and open/close indication .112
Figure B.16 – Local pressure indication, CCR pressure indication, high alarm and high
high safety relevant switch.112
Figure B.17 – Local pressure indication, CCR pressure indication, alarms and switches .112
Figure B.18 – CCR pressure indication, high and low alarm, safety relevant switch
action on on/off valve.112
Figure B.19 – Switched valve with on/off indication and switching action, safety
relevant switched valve.113
Figure B.20– Pressure restriction.113
Figure B.21 – Flow restriction .113
Figure B.22 – PT compensated flow control, safety-relevant pressure switch (two out of
three (2oo3) shutdown), switched control valve with on/off indication and switching
action at open position.114
Figure B.23 – CCR temperature control, additional manual switch actions from CCR
with indication and local control panel.114
Figure B.24 – Motor typical, local on/off control, CCR off control, current, fault with
alarm and running indication .115
Figure B.25 – Multivariable controller.115
Figure B.26 – On/off valve with position indication .116
Figure B.27 – On/off valve with safety relevant switch and position indication.116
Figure B.28 – Level control with continuous controller.116
Figure B.29 – Level control with on/off switch .116
Figure B.30 – Cascade control for temperature as control input, flow control as follow-
up controller .117
Figure B.31 – Safety directed high control to a subsequent valve, manual control for
reset function and manual control for manual/automatic switch of the valve, valve with
open/close indication and safety-relevant switch to subsequent valve.117
Figure B.32 – Flow control in CCR .117
Figure B.33 – Temperature control with high alarm and high switch .117
Figure B.34 – Manual control from CCR.118
Figure B.35 – Flow measurement with display and alarms in CCR, high high switch on
process control function and switch on/off valve .118

62424 © IEC:2008(E) – 5 –
Figure B.36 – Local P-/F-/T-/S- control without auxiliary power (stand-alone).118
Figure D.1 – Example CAEX interface library.128
Figure D.2 – Example CAEX role library .129
Figure D.3 – Example to be mapped with CAEX.131
Figure D.4 – CAEX model of the example described in Figure D.3 .132

Table 1 – Abbrevations .15
Table 2 – PCE categories .20
Table 3 – PCE processing function .21
Table 4 – Sequence combinations .22
Table 5 – PCE processing functions for actuators .22
Table 6 – P&ID attributes relevant in PCE environment .35
Table 7 – Data handling attributes .35
Table A.1 – XML notation conventions .36
Table A.2 – CAEX data types and elements.37

– 6 – 62424 © IEC:2008(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
REPRESENTATION OF PROCESS CONTROL ENGINEERING –
REQUESTS IN P&I DIAGRAMS AND DATA EXCHANGE
BETWEEN P&ID TOOLS AND PCE-CAE TOOLS

FOREWORD
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62424 has been prepared by IEC technical committee 65:
Industrial-process measurement, control and automation.
This standard cancels and replaces IEC/PAS 62424 published in 2005. This first edition
constitutes a technical revision.
The text of this standard is based on the following documents:
FDIS Report on voting
65/420/FDIS 65/428/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

62424 © IEC:2008(E) – 7 –
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

– 8 – 62424 © IEC:2008(E)
INTRODUCTION
Efficient process engineering requires highly sophisticated tools for the different needs of the
involved work processes and departments. These engineering tools are normally specialized
in Process Design (PD), in Process Control Engineering (PCE), etc. Therefore a working
interoperability is essential to optimize the engineering process in total. Thus, the definition of
a harmonized interface and data management is a core task to ensure a smooth workflow
during the whole project and to guarantee data consistency in the different tools.
This standard defines procedures and specifications for the exchange of PCE relevant data
provided by the Piping and Instrumentation Diagram (P&ID) tool. The basic requirements for a
change management procedure are described. A generally accepted technology for machine
information exchange, the Extensible Markup Language (XML) is used. Hereby, a common
basis is given for information integration.
However, a definition for uniform semantics is still necessary. CAEX (Computer Aided
Engineering eXchange) as it is defined in this document is an appropriate data format for this
purpose. This concept of data exchange is open for different applications.
The main task of a data exchange is transporting/synchronizing information from the P&ID
database to the PCE databases and vice versa. The owner's reference designation system
and a unique description of the processing requirement is the key for a unique identification.
For detailed information about representation of PCE loops in P&ID's see Clause 6.
The data exchange system may be a stand-alone, vendor independent application or a
module in an engineering environment. The data between a P&ID tool and a PCE tool and
vice versa is exchanged via CAEX.
After the data exchange, there are three places where information about the plant is stored.
Both the proprietary databases of the considered tools include private and common
information. Both are stored at different places and different divisions that are working on
them. Hereby, the intermediate database CAEX only stores common information. In a wider
approach, the intermediate database should store both common and private information. This
becomes important if a third application is connected to the neutral database. If the
intermediate database is used as a temporary data stream only (without storing the
information in a file), the information will be lost after processing the data conciliation.
Figure 1 illustrates the information flow for the P&ID and the PCE database reconciliation.
The data exchange is done via a neutral intermediate CAEX database, not directly from
database to database. The intermediate CAEX database should be a file (for file based data
exchange) or a stream (for network based data exchange). The term “CAEX database” within
this standard has to be understood in this way, it does not denominate a database product as
e. g. SQL.
Annex C of this standard contains the full XML schema of the CAEX Model. It is attached to
this publication in XSD format.
NOTE Buyers of this publication may copy it for their own purposes only in the required amount.

62424 © IEC:2008(E) – 9 –
P&ID
3D-Model
User
proprietary P&ID - Database
PCE relevant Intersection
modifications
addition
P&ID export/import application
error list
loops
Process designer
Further Further
CAEX
applications applications
(XML file with neutral data format)
XML-Files
XML-Files
PCE relevant Intersection
Process control engineer
error list
PCE import/export application
addition
loops
modifications
PCE - System
(loops, tags, process data)
PCE relevant
User
Intersection
Figure 1 – Information flow between P&ID and PCE tool

– 10 – 62424 © IEC:2008(E)
REPRESENTATION OF PROCESS CONTROL ENGINEERING –
REQUESTS IN P&I DIAGRAMS AND DATA EXCHANGE
BETWEEN P&ID TOOLS AND PCE-CAE TOOLS

1 Scope
This International Standard specifies how process control engineering requests are
represented in a P&ID for automatic transferring data between P&ID and PCE tool and to
avoid misinterpretation of graphical P&ID symbols for PCE.
It also defines the exchange of process control engineering request relevant data between a
process control engineering tool and a P&ID tool by means of a data transfer language (called
CAEX). These provisions apply to the export/import applications of such tools.
The representation of the PCE functionality in P&ID'S will be defined by a minimum number of
rules to clearly indicate their category and processing function, independent from the
technique of realization (see Clause 6). The definition of graphical symbols for process
equipment (e. g. vessels, valves, columns, etc.), their implementation and rules for the
reference designation system are not in the scope of this standard. These rules are
independent from this standard.
Clause 7 specifies the data flow between the different tools and the data model CAEX.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 61346-1, Industrial systems, installations and equipment and industrial products –
Structuring principles and reference designations – Part 1: Basic rules
IEC 61511-1, Functional safety – Safety instrumented systems for the process industry sector
– Part 1: Framework, definitions, system, hardware and software requirements
ISO 10628, Flow diagrams for process plants – General rules
ISO 13849-1, Safety of machinery – Safety-related parts of control systems – Part 1: General
principles for design
Extensible Markup Language (XML) 1.0 (Third Edition), W3C Recommendation 04 February
2004, available at
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
actuator
functional unit that generates from the controller output variable the manipulated variable
required to drive the final controlling element

62424 © IEC:2008(E) – 11 –
NOTE If the final controlling element is mechanically actuated, it is controlled via an actuating drive. The actuator
drives the actuating drive in this case.
[IEV 351-28-07]
EXAMPLE A practical example of an actuator acting directly on the final controlling element is a pneumatic
control valve.
3.2
adjusted nominal pipe size
size of the related pipe for the process connection of the PCE request in case of pipe
diameters size reduction based on process requirements
3.3
bubble
oval symbol used to denote the PCE category and processing function of a PCE request and
to uniquely identify a PCE request
NOTE On the basis of ISA S5.1, Clause 3.
3.4
control narrative
verbal description of a functional control scheme
3.5
design pressure
maximum pressure for which the system or component was designed for continuous usage
[ISO 13628-6, 3.4]
3.6
design temperature
maximum temperature for which the system or component was designed for continuous usage
3.7
equipment ID
unique identifier of equipment
3.8
equipment/pipe flag
unique identifier of equipment/pipe type
3.9
function chart
graphic description tool with symbolic representation of sequential control systems
NOTE 1 The symbolic representation of steps, commands, transitions and directed links is based on input and
output Boolean variables and also on internal state variables and binary delay elements.
NOTE 2 The elements, rules and basic structures for function charts are given in IEC 60848.
[IEV 351-29-22]
3.10
heat tracing
heating system for pipe to prevent freezing of process requirements
3.11
heat tracing type
type of heating system for pipe

– 12 – 62424 © IEC:2008(E)
EXAMPLE Steam or electrical heating system.
3.12
heat tracing temperature set point
set point for the controller of a heat tracing
3.13
insulation type
description of the used insulation type
EXAMPLE Sound insulation.
3.14
insulation thickness
thickness of insulation added to the outer diameter of the pipe size
3.15
intermediate database
intermediate data storage system between source and target tool
3.16
material balance point
balance point of the process calculation
3.17
medium code
abbreviation and identifier for the fluid running through a process pipe
3.18
medium code description
description of the fluid running through a process pipe
3.19
neutral database
vendor independent data storage system
3.20
PCE category
letter that designates the kind of process control engineering request
NOTE Unlike other standards, this standard uses the term "PCE category" instead of "measured variable" (e.g.
temperature measurement) for the first digit of the PCE request. The PCE category as defined in this standard
allows to unambiguously identify the kind of PCE request, without the need to specify a second letter as modifier
for actuators. Based on this, only one letter for sensor and actuator identification of PCE request is necessary.
3.21
PCE control function
function in a PCE control
NOTE According to IEC 61512-1.
3.22
PCE loop
collection of PCE requests and PCE control functions depicting their functional coherence
3.23
PCE request
requirement for process control equipment. Each PCE request is graphically represented by a
bubble which collects all information on the functional requirements

62424 © IEC:2008(E) – 13 –
3.24
pipe diameter size
nominal size of the related pipe for the process connection of the PCE request
3.25
pipe ID
unique identifier of pipe
EXAMPLE Isometrics number.
3.26
pipe specification
abbreviation and identifier for the specification of piping equipment. Defines the size, material,
design, pressure and temperature for all elements of a pipe
3.27
process control equipment
entirety of devices and programs and, in a broader sense, all instructions and programs used
for the task of controlling equipment having a process control function
NOTE 1 Control equipment also comprises the process control station and instructions include operating
manuals.
NOTE 2 Providing a process with control equipment is denoted as process automation.
[IEV 351-32-32, modified with respect to process supervison and control]
3.28
process control function
function to work on process variables (variable quantities), which is composed of basic
functions of process control, specific to units of the plant
NOTE In addition to process control functions associated with specific control levels, there can also be process
control functions that link input and output variables across several control levels. For instance, a process control
function in the feedback path with the controlled variable as input variable and the manipulated variable as output
variable, describes the action path from the sensor via the controller to the final controlling element. Another
process control function connects the operator with the indicators for the process variables. In view of the diversity
of definitions of process control functions, standardization is not appropriate at this time.
[IEV 351-31-17]
3.29
processing function
function in a process
NOTE A processing function serves a control module according to IEC 61512-1, 3.10 and 5.2.2.4.
3.30
proprietary database
vendor specific data storage system, with syntax and/or semantic not complying to any
standard
3.31
PU-vendor
Package Unit vendor
supplier of a process unit in a plant
3.32
reference designation
identifier of a specific object formed with respect to the system of which the object is a
constituent, based on one or more aspects of that system

– 14 – 62424 © IEC:2008(E)
NOTE 1 According to IEC 61346-1.
NOTE 2 Terms "object", "aspect" and "system" are defined in IEC 61346-1.
3.33
schema
XML based description of rules to which an XML document must conform in order to be
considered "valid" according to that schema
NOTE On the basis of Extensible Mark-up Language (XML) 1.0 (Third Edition), W3C Recommendation, Clause 2.
3.34
sensor
functional unit that senses the effect of a measured variable at its input and places a
corresponding measurement signal at its output
NOTE 1 The corresponding physical unit is named sensor or detecting device.
NOTE 2 Examples of sensors are
a) thermocouple
b) foil strain gauge
c) pH electrode.
[IEV 351-32-39, modified]
3.35
source database
data storage system of the source tool
3.36
target database
data storage system of the target tool
3.37
typical
abbreviation and identifier for a graphical diagram in a database or a group of signals
4 Abbreviations
Table 1 shows abbreviations used in this standard.

62424 © IEC:2008(E) – 15 –
Table 1 – Abbrevations
CAE Computer Aided Engineering
CAEX Computer Aided Engineering eXchange
CCR Central Control Room
GMP Good Manufacturing Practice
N.A. Not Applicable
PCE Process Control Engineering
PCS Process Control System
P&ID Piping and Instrumentation Diagram
PD Process design
PL Performance level according to ISO 13849-1
PU Package Unit
SIL Safety Integrity Level acc. to IEC 61511-1
SIS Safety Instrumented System according to IEC 61511-1
XML Extensible Markup Language
5 Conformity
To claim conformity to this standard with respect to the graphical representation of PCE
requests in P&ID’s, the requirements of Clause 6 shall be fulfilled.
To claim conformity to this standard with respect to the PCE relevant data exchange, the
requirements of Clause 7 and the following requirements shall be fulfilled.
The data exchange shall be performed by a separate or integrated import/export application
that provides for the data exchange between the related tool and CAEX.
NOTE The goal of the import/export application is to provide for data reconciliation for the intersection of the
source and target databases. It is able to read the proprietary database of the considered tool and to reconciliate
the data with the neutral CAEX database.
The export/import application shall check, report and provide the intersection data of both
databases. The neutral database shall be open for additional applications.
The data import function shall enforce a configurable checking step (e. g. rule based) during
the import process; it shall not allow unguided automatic changes. The configurable checking
step shall include functionality for automatic or manual acceptance of data changes, allowing
single decisions up to bulk data management.
All changes in the proprietary database and all discovered data inconsistencies shall be
reported by the import application. The generation of the report shall be configurable. The
import/export application has to assure that the intersection of the different databases
contains the same information, and that additional division specific data is handled in a
consistent way. Data manipulation by a project division is an ongoing process during the
whole project and beyond it. Thus the creation, changing and deletion of data shall be
possible during the life-cycle of the plant.
CAEX databases have to be consistent. This requires a consistency check before exporting
the data. This procedure has to be followed after a successful data manipulation in a
P&ID tool or PCE tool in order to bring the new information into the neutral database or vice
versa. Before any data changing action is carried out, the user shall be informed and asked
for confirmation. The consistency check shall encompass at least the following steps and
fulfill the following requirements:

– 16 – 62424 © IEC:2008(E)
Data export from source database to neutral database shall comprise the following activities:
a) check P&ID and PCE database for at least:
1) duplicate PCE requests or loop designations;
2) mandatory fields being filled in;
3) correct use of numbering system of the PCE requests.
Inconsistent data shall not be exported.
b) generate PCE relevant information;
c) check for changed information in comparison with previously stored data in the neutral
database;
d) renaming of PCE request shall be supported by the export functionality;
e) perform data export from proprietary into neutral database:
1) e. g. if the PCE request has been changed, the old PCE request within the neutral
database has to be deleted and the new one shall be exported from the proprietary
database into the neutral database. The old PCE request information shall be stored in
a backup storage system;
2) Other changes shall be performed with the existing object.
f) generate reports after each data exchange:
e. g. new PCE requests list, missing PCE requests list, changed PCE requests list,
deleted PCE requests list, problems and error list.
Data import from neutral database into the target database shall comprise the following
activities:
g) generate PCE relevant information from neutral database;
h) check for changed information by comparing the neutral database with the target
database;
i) perform data import from the neutral into the proprietary database;
j) renaming of PCE request shall be supported by the import functionality;
k) generate reports after each data exchange:
1) e. g. error lists;
2) inconsistencies due to imported data shall be detected by the target application during
the import process and are not considered within this standard.
6 Representation of PCE requests in a P&ID
6.1 PCE request and PCE loop
In a P&ID the functional design of a plant is determined. Details of technical equipment are
given only if functions are correlated with the design of specific equipment. Consequentially,
the P&ID describes requirements for the design of the process control equipment. Each PCE
request shall be illustrated in the P&ID with an individual identification. In order to meet the
requirements of data handling, the same identification shall not be used for different PCE
requests. Functional coherence should be depicted by collecting the individual PCE requests
in a PCE loop. A PCE loop does not have a graphical representation. Depending on the
engineering strategy, a PCE loop thereby consists of at least one, but may also combine
several PCE requests. If PCE loops are used, these shall be represented in the identification
of all concerned PCE requests. An example of this concept is given in Figure 2.

62424 © IEC:2008(E) – 17 –
PCE loop xxxx
PCE request
(optional)
SHH
AH
TI
xxxx.1
a
PCE request PCE control function PCE request
SHH
OH
AH
FI
US YS
xxxx.2 AL
xxxx.3 xxxx.4
a
The PCE control function used in Figure 2 is defined in 6.3.10
Figure 2 – Organization of PCE requests
6.2 Objectives and principles
This subclause defines how to represent the process control engineering functionality in
P&ID's. Technical details of the used equipment shall not be depicted in general. This is due
to the goal to ensure a smooth engineering workflow by separating process and
instrumentation design.
Therefore the following items are set out in the standard:
a) the PCE categories and functions;
b) the graphical representation of PCE requests in a P&ID;
c) the type of functional connection between the PCE requests: the control functions;
d) the graphical representation of signals in a P&ID.
In addition the reference designation scheme used for PCE requests in a P&ID shall be
specified.
Detailed information on complex control functions shall not be
...

IEC 62424 ®
Edition 1.0 2008-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Representation of process control engineering – Requests in P&I diagrams and
data exchange between P&ID tools and PCE-CAE tools

Représentation de l’ingénierie de commande de processus – Demandes sous
forme de diagrammes P&I et échange de données entre outils P&ID et outils
PCE-CAE
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IEC 62424 ®
Edition 1.0 2008-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Representation of process control engineering – Requests in P&I diagrams and

data exchange between P&ID tools and PCE-CAE tools

Représentation de l’ingénierie de commande de processus – Demandes sous

forme de diagrammes P&I et échange de données entre outils P&ID et outils

PCE-CAE
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XF
ICS 35.240.50; 25.040.40 ISBN 978-2-83220-537-2

– 2 – 62424  IEC:2008
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 10
2 Normative references . 10
3 Terms and definitions . 10
4 Abbreviations . 14
5 Conformity . 15
6 Representation of PCE requests in a P&ID . 16
6.1 PCE request and PCE loop . 16
6.2 Objectives and principles . 17
6.3 Requirements for the identification and representation of PCE requests . 17
6.3.1 General . 17
6.3.2 Types of lines . 18
6.3.3 Displaying the location of the operator interface . 18
6.3.4 PCE categories and processing functions . 19
6.3.5 PCE request reference designation scheme . 22
6.3.6 PU-vendor and typical identification . 23
6.3.7 Device information . 23
6.3.8 Alarming, switching and indicating . 24
6.3.9 Safety-relevant, GMP and quality-relevant PCE requests . 24
6.3.10 PCE control functions . 25
7 Neutral data exchange of PCE relevant P&ID information . 26
7.1 Objectives . 26
7.2 Meaning of P&ID elements . 26
7.3 PCE relevant information of P&ID tools . 27
7.4 Formal description of PCE relevant information of P&ID tools . 28
7.4.1 General . 28
7.4.2 Modeling PCE relevant information using the CAEX system
description language . 29
7.4.3 Basic CAEX mappings . 29
7.4.4 Mapping of a PCE request interface to an external interface of the
corresponding plant hierarchy item . 31
7.4.5 CAEX description of direct links between PCE request interfaces of
different plant hierarchy items . 33
7.4.6 PCE loops . 34
8 Additional PCE attributes . 35
Annex A (normative) CAEX – Data model for machine information exchange . 36
Annex B (informative) Examples of PCE requests . 109
Annex C (normative) Full XML schema of the CAEX Model . 119
Annex D (informative) CAEX modelling examples . 128
Bibliography . 135

Figure 1 – Information flow between P&ID and PCE tool . 9
Figure 2 – Organization of PCE requests . 17
Figure 3 – General representation of a PCE-Request in a P&ID . 18

62424  IEC:2008 – 3 –
Figure 4 – Multi-sensor element . 18
Figure 5 – Local interface . 19
Figure 6 – Manually operated switch in local control panel . 19
Figure 7 – Pressure indication in central control room . 19
Figure 8 – Example of PCE request identification . 23
Figure 9 – Example of flow measurement with indication in the CCR delivered by
vendor A specified by typical A20 . 23
Figure 10 – Example of pH-measurement with indication in the CCR . 23
Figure 11 – Example of flow measurement with indication in the CCR and high and
low alarm . 24
Figure 12 – Flow measurement with indication in the CCR and high alarm and a high-
high switching function . 24
Figure 13 – Flow measurement with indication in the CCR and a high-high switch limit,
a high alarm, a low alarm and a low-low switch limit for a safety function . 24
Figure 14 – GMP relevant, safety relevant and quality relevant flow measurement with
indication in the CCR . 25
Figure 15 – Control function . 25
Figure 16 – Safety relevant control function . 25
Figure 17 – P&ID elements and associations (PCE relevant items are shown in dark
lines) . 27
Figure 18 – Process data model (PCE relevant items are shown in dark lines) . 28
Figure 19 – PCE request data model . 30
Figure 20 – Example of two plant sections and a signal connection via external
interfaces . 32
Figure 21 – Simplified CAEX model of indirect links between PCE requests across
different plant hierarchy items . 32
Figure 22 – Example of two plant sections and a direct connection . 33
Figure 23 – Simplified CAEX model of direct links between PCE requests across
different plant hierarchy items . 34
Figure A.1 – CAEX architecture of a SystemUnitClass . 42
Figure A.2 – Example of a SystemUnitClassLib. 42
Figure A.3 – Examples of Attributes . 44
Figure A.4 – Examples of an InterfaceClassLib . 46
Figure A.5 – Usage of Links . 47
Figure A.6 – Example of a RoleClassLib . 48
Figure A.7 – CAEX Role Concept . 50
Figure A.8 – CAEX data definition for use case 1 . 50
Figure A.9 – CAEX data definition for use case 2 . 51
Figure A.10 – CAEX data definition for use case 3 . 51
Figure A.11 – CAEX data definition of a MappingObject . 53
Figure A.12 – Example for a hierarchical plant structure . 53
Figure A.13 – CAEX data structure . 54
Figure A.14 – Distribution of data in several CAEX files . 54
Figure A.15 – Referencing of external CAEX files . 54
Figure A.16 – Example of how to use alias names . 55
Figure A.17 – Multiple crossed structures . 56

– 4 – 62424  IEC:2008
Figure B.1 – Local level indication, 1 process connection . 109
Figure B.2 – Local level indication, 2 process connections . 109
Figure B.3 – Local flow indication . 109
Figure B.4 – Local pressure indication . 109
Figure B.5 – Local temperature indication . 109
Figure B.6 – Local control panel, pressure indication, high alarm . 110
Figure B.7 – Local temperature indication, CCR temperature high alarm . 110
Figure B.8 – Local pressure indication, CCR pressure high alarm and switch. 110
Figure B.9 – CCR flow indication, device information: Orifice Plate . 110
Figure B.10 – CCR pressure indication, low, low low and high alarm . 110
Figure B.11 – CCR temperature indication and registration . 111
Figure B.12 – CCR level indication and registration, 1 process connection . 111
Figure B.13 – CCR level indication, 2 process connections . 111
Figure B.14 – Two flow indications and flow ratio control in CCR . 111
Figure B.15 – CCR flow indication and high alarm, flow control, control valve with extra
interlock and open/close indication . 112
Figure B.16 – Local pressure indication, CCR pressure indication, high alarm and high
high safety relevant switch . 112
Figure B.17 – Local pressure indication, CCR pressure indication, alarms and switches . 112
Figure B.18 – CCR pressure indication, high and low alarm, safety relevant switch
action on on/off valve . 112
Figure B.19 – Switched valve with on/off indication and switching action, safety
relevant switched valve . 113
Figure B.20– Pressure restriction . 113
Figure B.21 – Flow restriction . 113
Figure B.22 – PT compensated flow control, safety-relevant pressure switch (two out of
three (2oo3) shutdown), switched control valve with on/off indication and switching
action at open position . 114
Figure B.23 – CCR temperature control, additional manual switch actions from CCR
with indication and local control panel . 114
Figure B.24 – Motor typical, local on/off control, CCR off control, current, fault with
alarm and running indication . 115
Figure B.25 – Multivariable controller . 115
Figure B.26 – On/off valve with position indication . 116
Figure B.27 – On/off valve with safety relevant switch and position indication . 116
Figure B.28 – Level control with continuous controller. 116
Figure B.29 – Level control with on/off switch . 116
Figure B.30 – Cascade control for temperature as control input, flow control as follow-
up controller . 117
Figure B.31 – Safety directed high control to a subsequent valve, manual control for
reset function and manual control for manual/automatic switch of the valve, valve with
open/close indication and safety-relevant switch to subsequent valve . 117
Figure B.32 – Flow control in CCR . 117
Figure B.33 – Temperature control with high alarm and high switch . 117
Figure B.34 – Manual control from CCR . 118
Figure B.35 – Flow measurement with display and alarms in CCR, high high switch on
process control function and switch on/off valve . 118

62424  IEC:2008 – 5 –
Figure B.36 – Local P-/F-/T-/S- control without auxiliary power (stand-alone). 118
Figure D.1 – Example CAEX interface library . 128
Figure D.2 – Example CAEX role library . 129
Figure D.3 – Example to be mapped with CAEX . 131
Figure D.4 – CAEX model of the example described in Figure D.3 . 132

Table 1 – Abbrevations . 15
Table 2 – PCE categories . 20
Table 3 – PCE processing function . 21
Table 4 – Sequence combinations . 22
Table 5 – PCE processing functions for actuators . 22
Table 6 – P&ID attributes relevant in PCE environment . 35
Table 7 – Data handling attributes . 35
Table A.1 – XML notation conventions . 36
Table A.2 – CAEX data types and elements . 37

– 6 – 62424  IEC:2008
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
REPRESENTATION OF PROCESS CONTROL ENGINEERING –
REQUESTS IN P&I DIAGRAMS AND DATA EXCHANGE
BETWEEN P&ID TOOLS AND PCE-CAE TOOLS

FOREWORD
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62424 has been prepared by IEC technical committee 65:
Industrial-process measurement, control and automation.
This standard cancels and replaces IEC/PAS 62424 published in 2005. This first edition
constitutes a technical revision.
This bilingual version (2012-12) corresponds to the monolingual English version, published in
2008-08.
The text of this standard is based on the following documents:
FDIS Report on voting
65/420/FDIS 65/428/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.

62424  IEC:2008 – 7 –
The French version of this standard has not been voted upon.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication
indicates that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 8 – 62424  IEC:2008
INTRODUCTION
Efficient process engineering requires highly sophisticated tools for the different needs of the
involved work processes and departments. These engineering tools are normally specialized
in Process Design (PD), in Process Control Engineering (PCE), etc. Therefore a working
interoperability is essential to optimize the engineering process in total. Thus, the definition of
a harmonized interface and data management is a core task to ensure a smooth workflow
during the whole project and to guarantee data consistency in the different tools.
This standard defines procedures and specifications for the exchange of PCE relevant data
provided by the Piping and Instrumentation Diagram (P&ID) tool. The basic requirements for a
change management procedure are described. A generally accepted technology for machine
information exchange, the Extensible Markup Language (XML) is used. Hereby, a common
basis is given for information integration.
However, a definition for uniform semantics is still necessary. CAEX (Computer Aided
Engineering eXchange) as it is defined in this document is an appropriate data format for this
purpose. This concept of data exchange is open for different applications.
The main task of a data exchange is transporting/synchronizing information from the P&ID
database to the PCE databases and vice versa. The owner's reference designation system
and a unique description of the processing requirement is the key for a unique identification.
For detailed information about representation of PCE loops in P&ID's see Clause 6.
The data exchange system may be a stand-alone, vendor independent application or a
module in an engineering environment. The data between a P&ID tool and a PCE tool and
vice versa is exchanged via CAEX.
After the data exchange, there are three places where information about the plant is stored.
Both the proprietary databases of the considered tools include private and common
information. Both are stored at different places and different divisions that are working on
them. Hereby, the intermediate database CAEX only stores common information. In a wider
approach, the intermediate database should store both common and private information. This
becomes important if a third application is connected to the neutral database. If the
intermediate database is used as a temporary data stream only (without storing the
information in a file), the information will be lost after processing the data conciliation.
Figure 1 illustrates the information flow for the P&ID and the PCE database reconciliation.
The data exchange is done via a neutral intermediate CAEX database, not directly from
database to database. The intermediate CAEX database should be a file (for file based data
exchange) or a stream (for network based data exchange). The term “CAEX database” within
this standard has to be understood in this way, it does not denominate a database product as
e. g. SQL.
Annex C of this standard contains the full XML schema of the CAEX Model. It is attached to
this publication in XSD format.
NOTE Buyers of this publication may copy it for their own purposes only in the required amount.

62424  IEC:2008 – 9 –
P&ID
3D-Model
User
proprietary P&ID - Database
PCE relevant Intersection
modifications
addition
P&ID export/import application
error list
loops
Process designer
Further Further
CAEX
applications applications
(XML file with neutral data format)
XML-Files
XML-Files
PCE relevant Intersection
Process control engineer
error list
PCE import/export application
addition
loops
modifications
PCE - System
(loops, tags, process data)
PCE relevant
User
Intersection
Figure 1 – Information flow between P&ID and PCE tool

– 10 – 62424  IEC:2008
REPRESENTATION OF PROCESS CONTROL ENGINEERING –
REQUESTS IN P&I DIAGRAMS AND DATA EXCHANGE
BETWEEN P&ID TOOLS AND PCE-CAE TOOLS

1 Scope
This International Standard specifies how process control engineering requests are
represented in a P&ID for automatic transferring data between P&ID and PCE tool and to
avoid misinterpretation of graphical P&ID symbols for PCE.
It also defines the exchange of process control engineering request relevant data between a
process control engineering tool and a P&ID tool by means of a data transfer language (called
CAEX). These provisions apply to the export/import applications of such tools.
The representation of the PCE functionality in P&ID'S will be defined by a minimum number of
rules to clearly indicate their category and processing function, independent from the
technique of realization (see Clause 6). The definition of graphical symbols for process
equipment (e. g. vessels, valves, columns, etc.), their implementation and rules for the
reference designation system are not in the scope of this standard. These rules are
independent from this standard.
Clause 7 specifies the data flow between the different tools and the data model CAEX.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 61346-1, Industrial systems, installations and equipment and industrial products –
Structuring principles and reference designations – Part 1: Basic rules
IEC 61511-1, Functional safety – Safety instrumented systems for the process industry sector
– Part 1: Framework, definitions, system, hardware and software requirements
ISO 10628, Flow diagrams for process plants – General rules
ISO 13849-1, Safety of machinery – Safety-related parts of control systems – Part 1: General
principles for design
Extensible Markup Language (XML) 1.0 (Third Edition), W3C Recommendation 04 February
2004, available at
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
actuator
functional unit that generates from the controller output variable the manipulated variable
required to drive the final controlling element

62424  IEC:2008 – 11 –
NOTE If the final controlling element is mechanically actuated, it is controlled via an actuating drive. The actuator
drives the actuating drive in this case.
[IEV 351-28-07]
EXAMPLE A practical example of an actuator acting directly on the final controlling element is a pneumatic
control valve.
3.2
adjusted nominal pipe size
size of the related pipe for the process connection of the PCE request in case of pipe
diameters size reduction based on process requirements
3.3
bubble
oval symbol used to denote the PCE category and processing function of a PCE request and
to uniquely identify a PCE request
NOTE On the basis of ISA S5.1, Clause 3.
3.4
control narrative
verbal description of a functional control scheme
3.5
design pressure
maximum pressure for which the system or component was designed for continuous usage
[ISO 13628-6, 3.4]
3.6
design temperature
maximum temperature for which the system or component was designed for continuous usage
3.7
equipment ID
unique identifier of equipment
3.8
equipment/pipe flag
unique identifier of equipment/pipe type
3.9
function chart
graphic description tool with symbolic representation of sequential control systems
NOTE 1 The symbolic representation of steps, commands, transitions and directed links is based on input and
output Boolean variables and also on internal state variables and binary delay elements.
NOTE 2 The elements, rules and basic structures for function charts are given in IEC 60848.
[IEV 351-29-22]
3.10
heat tracing
heating system for pipe to prevent freezing of process requirements
3.11
heat tracing type
type of heating system for pipe

– 12 – 62424  IEC:2008
EXAMPLE Steam or electrical heating system.
3.12
heat tracing temperature set point
set point for the controller of a heat tracing
3.13
insulation type
description of the used insulation type
EXAMPLE Sound insulation.
3.14
insulation thickness
thickness of insulation added to the outer diameter of the pipe size
3.15
intermediate database
intermediate data storage system between source and target tool
3.16
material balance point
balance point of the process calculation
3.17
medium code
abbreviation and identifier for the fluid running through a process pipe
3.18
medium code description
description of the fluid running through a process pipe
3.19
neutral database
vendor independent data storage system
3.20
PCE category
letter that designates the kind of process control engineering request
NOTE Unlike other standards, this standard uses the term "PCE category" instead of "measured variable" (e.g.
temperature measurement) for the first digit of the PCE request. The PCE category as defined in this standard
allows to unambiguously identify the kind of PCE request, without the need to specify a second letter as modifier
for actuators. Based on this, only one letter for sensor and actuator identification of PCE request is necessary.
3.21
PCE control function
function in a PCE control
NOTE According to IEC 61512-1.
3.22
PCE loop
collection of PCE requests and PCE control functions depicting their functional coherence
3.23
PCE request
requirement for process control equipment. Each PCE request is graphically represented by a
bubble which collects all information on the functional requirements

62424  IEC:2008 – 13 –
3.24
pipe diameter size
nominal size of the related pipe for the process connection of the PCE request
3.25
pipe ID
unique identifier of pipe
EXAMPLE Isometrics number.
3.26
pipe specification
abbreviation and identifier for the specification of piping equipment. Defines the size, material,
design, pressure and temperature for all elements of a pipe
3.27
process control equipment
entirety of devices and programs and, in a broader sense, all instructions and programs used
for the task of controlling equipment having a process control function
NOTE 1 Control equipment also comprises the process control station and instructions include operating
manuals.
NOTE 2 Providing a process with control equipment is denoted as process automation.
[IEV 351-32-32, modified with respect to process supervison and control]
3.28
process control function
function to work on process variables (variable quantities), which is composed of basic
functions of process control, specific to units of the plant
NOTE In addition to process control functions associated with specific control levels, there can also be process
control functions that link input and output variables across several control levels. For instance, a process control
function in the feedback path with the controlled variable as input variable and the manipulated variable as output
variable, describes the action path from the sensor via the controller to the final controlling element. Another
process control function connects the operator with the indicators for the process variables. In view of the diversity
of definitions of process control functions, standardization is not appropriate at this time.
[IEV 351-31-17]
3.29
processing function
function in a process
NOTE A processing function serves a control module according to IEC 61512-1, 3.10 and 5.2.2.4.
3.30
proprietary database
vendor specific data storage system, with syntax and/or semantic not complying to any
standard
3.31
PU-vendor
Package Unit vendor
supplier of a process unit in a plant
3.32
reference designation
identifier of a specific object formed with respect to the system of which the object is a
constituent, based on one or more aspects of that system

– 14 – 62424  IEC:2008
NOTE 1 According to IEC 61346-1.
NOTE 2 Terms "object", "aspect" and "system" are defined in IEC 61346-1.
3.33
schema
XML based description of rules to which an XML document must conform in order to be
considered "valid" according to that schema
NOTE On the basis of Extensible Mark-up Language (XML) 1.0 (Third Edition), W3C Recommendation, Clause 2.
3.34
sensor
functional unit that senses the effect of a measured variable at its input and places a
corresponding measurement signal at its output
NOTE 1 The corresponding physical unit is named sensor or detecting device.
NOTE 2 Examples of sensors are
a) thermocouple
b) foil strain gauge
c) pH electrode.
[IEV 351-32-39, modified]
3.35
source database
data storage system of the source tool
3.36
target database
data storage system of the target tool
3.37
typical
abbreviation and identifier for a graphical diagram in a database or a group of signals
4 Abbreviations
Table 1 shows abbreviations used in this standard.

62424  IEC:2008 – 15 –
Table 1 – Abbrevations
CAE Computer Aided Engineering
CAEX Computer Aided Engineering eXchange
CCR Central Control Room
GMP Good Manufacturing Practice
N.A. Not Applicable
PCE Process Control Engineering
PCS Process Control System
P&ID Piping and Instrumentation Diagram
PD Process design
PL Performance level according to ISO 13849-1
PU Package Unit
SIL Safety Integrity Level acc. to IEC 61511-1
SIS Safety Instrumented System according to IEC 61511-1
XML Extensible Markup Language
5 Conformity
To claim conformity to this standard with respect to the graphical representation of PCE
requests in P&ID’s, the requirements of Clause 6 shall be fulfilled.
To claim conformity to this standard with respect to the PCE relevant data exchange, the
requirements of Clause 7 and the following requirements shall be fulfilled.
The data exchange shall be performed by a separate or integrated import/export application
that provides for the data exchange between the related tool and CAEX.
NOTE The goal of the import/export application is to provide for data reconciliation for the intersection of the
source and target databases. It is able to read the proprietary database of the considered tool and to reconciliate
the data with the neutral CAEX database.
The export/import application shall check, report and provide the intersection data of both
databases. The neutral database shall be open for additional applications.
The data import function shall enforce a configurable checking step (e. g. rule based) during
the import process; it shall not allow unguided automatic changes. The configurable checking
step shall include functionality for automatic or manual acceptance of data changes, allowing
single decisions up to bulk data management.
All changes in the proprietary database and all discovered data inconsistencies shall be
reported by the import application. The generation of the report shall be configurable. The
import/export application has to assure that the intersection of the different databases
contains the same information, and that additional division specific data is handled in a
consistent way. Data manipulation by a project division is an ongoing process during the
whole project and beyond it. Thus the creation, changing and deletion of data shall be
possible during the life-cycle of the plant.
CAEX databases have to be consistent. This requires a consistency check before exporting
the data. This procedure has to be followed after a successful data manipulation in a
P&ID tool or PCE tool in order to bring the new information into the neutral database or vice
versa. Before any data changing action is carried out, the user shall be informed and asked
for confirmation. The consistency check shall encompass at least the following steps and
fulfill the following requirements:

– 16 – 62424  IEC:2008
Data export from source database to neutral database shall comprise the following activities:
a) check P&ID and PCE database for at least:
1) duplicate PCE requests or loop designations;
2) mandatory fields being filled in;
3) correct use of numbering system of the PCE requests.
Inconsistent data shall not be exported.
b) generate PCE relevant information;
c) check for changed information in comparison with previously stored data in the neutral
database;
d) renami
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