IEC 61500:2009

IEC 61500 ®
Edition 2.0 2009-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Nuclear power plants – Instrumentation and control important to safety – Data
communication in systems performing category A functions

Centrales nucléaires de puissance – Instrumentation et contrôle-commande
importants pour la sûreté – Communication de données dans les systèmes
réalisant des fonctions de catégorie A

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IEC 61500 ®
Edition 2.0 2009-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Nuclear power plants – Instrumentation and control important to safety – Data
communication in systems performing category A functions

Centrales nucléaires de puissance – Instrumentation et contrôle-commande
importants pour la sûreté – Communication de données dans les systèmes
réalisant des fonctions de catégorie A

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
P
CODE PRIX
ICS 27.120.20 ISBN 978-2-88910-523-6
– 2 – 61500 © IEC:2009
CONTENTS
FOREWORD.3

INTRODUCTION.5

1 Scope.7

2 Normative references .7

3 Terms and definitions .8

4 Symbols and abbreviations.9

5 General requirements .9

5.1 Principles of selection of data communication techniques and equipment.9
5.2 Functional requirements .9
5.3 Performance requirements .10
5.4 Failure detection .10
5.5 Communication within division.10
5.6 Interfaces to systems of lower importance to safety.10
6 Physical separation and isolation.11
6.1 Electrical isolation .11
6.2 Physical separation .11
7 Functional independence.11
8 Reliability .12
8.1 Self-supervision and failure mitigation .12
8.1.1 Communication error detection .12
8.1.2 Response to failure .12
8.2 Test.12
8.3 Prevention of failures (including CCF) .13
9 Qualification .13
10 Maintenance and modification .14
Bibliography.15

61500 © IEC:2009 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
NUCLEAR POWER PLANTS –
INSTRUMENTATION AND CONTROL IMPORTANT TO SAFETY –

DATA COMMUNICATION IN SYSTEMS PERFORMING

CATEGORY A FUNCTIONS
FOREWORD
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International Standard IEC 61500 has been prepared by subcommittee 45A: Instrumentation
and control of nuclear facilities, of IEC technical committee 45: Nuclear instrumentation.
This second edition cancels and replaces the first edition published in 1996. This edition
constitutes a technical revision.
The revision of the standard is intended to accomplish the following:
• To change the focus from multiplexed data transmission to data communication
• To restrict the scope to communication in systems performing category A functions
• To clarify definitions
• To up-date the reference to new standards published since the first issue.

– 4 – 61500 © IEC:2009
The text of this standard is based on the following documents:

FDIS Report on voting
45A/772/FDIS 45A/783/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.

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.
61500 © IEC:2009 – 5 –
INTRODUCTION
a) Technical background, main issues and organization of the standard

The equipment for data communication of on-line plant data can simplify the hardwired cables
connecting distributed systems for instrumentation, control, protection and monitoring needed

for safe Nuclear Power Plants operation. Such communication systems can have advantages

over direct cables, for electrical isolation, for reduction of cable fire loads or other reasons. In

a distributed computer based system, communication equipment is an essential part of the

system. Data communication is usually essential for implementing I&C systems important to

safety in nuclear power plants.

It is intended that the standard be used by operators of NPPs (utilities), manufacturers of data
communication equipment, systems evaluators and by licenso
...