M/490 - Smart Grid

This part of IEC 62541 is part of the overall OPC Unified Architecture (OPC UA) standard series and defines the information model associated with Data Access (DA). It particularly includes additional VariableTypes and complementary descriptions of the NodeClasses and Attributes needed for Data Access, additional Properties, and other information and behaviour.
The complete address space model, including all NodeClasses and Attributes is specified in IEC 62541-3. The services to detect and access data are specified in IEC 62541-4.
Annex A specifies how the information received from OPC COM Data Access (DA) Servers is mapped to the Data Access model.

IEC 62541-7: 2025 specifies value and structure of Profiles in the OPC Unified Architecture.
OPC UA Profiles are used to segregate features with regard to testing of OPC UA products and the nature of the testing. The scope of this document includes defining functionality that can only be tested. The definition of actual TestCases is not within the scope of this document, but the general categories of TestCases are covered by this document.
Most OPC UA applications will conform to several, but not all of the Profiles.
This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) Profiles and ConformanceUnits are not part of this document, but are solely managed in a public database as described in Clause 1.

This part of IEC 62541 defines the Information Model associated with Programs in OPC Unified Architecture (OPC UA). This includes the description of the NodeClasses, standard Properties, Methods and Events and associated behaviour and information for Programs.
The complete AddressSpace model including all NodeClasses and Attributes is specified in IEC 62541-3. The Services such as those used to invoke the Methods used to manage
Programs are specified in IEC 62541-4.
An example for a DomainDownload Program is defined in Annex A.

This part of IEC 62541 is part of the overall OPC Unified Architecture specification series and defines the information model associated with Aggregates.
Programmatically produced aggregate examples are listed in Annex A.

This part of IEC 62541 defines the OPC Unified Architecture (OPC UA) Services. The Services defined are the collection of abstract Remote Procedure Calls (RPC) that are implemented by OPC UA Servers and called by OPC UA Clients. All interactions between OPC UA Clients and Servers occur via these Services. The defined Services are considered abstract because no particular RPC mechanism for implementation is defined in this document. IEC 62541-6 specifies one or more concrete mappings supported for implementation. For example, one mapping in IEC 62541-6 is to UA-TCP UA-SC UA-Binary. In that case the Services described in this document appear as OPC UA Binary encoded payload, secured with OPC UA Secure Conversation and transported via OPC UA TCP.
Not all OPC UA Servers implement all of the defined Services. IEC 62541-7 defines the Profiles that dictate which Services must be implemented in order to be compliant with a particular Profile.
A BNF (Backus-Naur form) for browse path names is described in Annex A.

IEC 62541-100:2025 defines the information model associated with Devices. This document describes three models which build upon each other as follows:
• The (base) Device Model is intended to provide a unified view of devices and their hardware and software parts irrespective of the underlying device protocols.
• The Device Communication Model adds Network and Connection information elements so that communication topologies can be created.
• The Device Integration Host Model finally adds additional elements and rules required for host systems to manage integration for a complete system. It enables reflecting the topology of the automation system with the devices as well as the connecting communication networks.
This document also defines AddIns that can be used for the models in this document but also for models in other information models. They are:
• Locking model – a generic AddIn to control concurrent access,
• Software update model – an AddIn to manage software in a Device.
This second edition cancels and replaces the first edition published in 2015. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a a ComponentType that can be used to model any HW or SW element of a device has been defined and a SoftwareType has been added as subtype of ComponentType;
b the new OPC UA interface concept and defined interfaces for Nameplate, DeviceHealth, and SupportInfo has been added.
c) a new model for Software Update (Firmware Update) has been added;
d) a new entry point for documents where each document is represented by a FileType instance has been specified;
e) a model that provides information about the lifetime, related limits and semantic of the lifetime of things like tools, material or machines has been added.

IEC 62541-5:2026 This edition includes the following significant technical changes with respect to the previous edition:
a) Annex B has been removed and used to create IEC 62451-16;
b) Annex C has been removed and used to create IEC 62451-20;
c) currency information model has been added;
d) information model for Interfaces and AddIns has been added;
e) information model for Method Metadata has been added;
f) MaxSessions, MaxSubscriptions, and MaxMonitoredItems have been added to capabilities;
g) information model for ordered list of objects has been added;
h) PortableQualifiedName and PortableNodeId DataTypes have been added;
i) UriString DataType has been added;
j) SemanticVersionString DataType has been added;
k) AssociatedWith Reference Type has been added;
l) ConfigurationVersion Property has been added to NamespaceMetadataType;
m) AuditClientEventType and AuditClientUpdateMethodResultEventType have been added;
n) ModelVersion has been added to NamespaceMetadataType;
o) NoTransparentBackupRedundancyType has been added to support a Primary/Standby use case;
p) BitFieldType and BitFieldDefinitionType have been added.
This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision.

IEC 62541-6:2025 specifies the mapping between the security model described in IEC 62541‑2, the abstract service definitions specified in IEC 62541‑4, the data structures defined in IEC 62541‑5 and the physical network protocols that can be used to implement the OPC UA specification.
This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) addition of support for ECC to UA Secure Conversation;
b) use of the AuthorityKeyIdentifier extension in Certificate Revocation Lists;
c) enhancement of JSON mapping of Unions;
d) addition of Decimal data type encoding.
e) description of ECC keyUsage rules;
f) addition of Media assigned by IANA to UANodeSet definition;
g) addition of requirements for user and issuer Certificates;
h) addition of rules which specify what happens when DateTime precision is lost;
i) addition of rules to allow for the truncation of strings containing embedded nulls.
J) definition of a normative string representation for NodeId, ExpandedNodeId and QualifiedName for JSON mapping.
k) requirement that TAI times be converted to UTC;
l) new possibility to omit Symbol if unknown in JSON encoding;
m) addition of fields needed to support RolePermissions to the UANodeSet

This part of IEC 62541 belongs to the OPC Unified Architecture standards series and defines the Information Model associated with Historical Access (HA). It particularly includes additional and complementary descriptions of the NodeClasses and Attributes needed for Historical Access, additional standard Properties, and other information and behaviour.
The complete AddressSpace Model including all NodeClasses and Attributes is specified in IEC 62541-3. The predefined Information Model is defined in IEC 62541-5. The Services to detect and access historical data and events, and description of the ExtensibleParameter types are specified in IEC 62541-4.
This document includes functionality to compute and return Aggregates like minimum, maximum, average etc. The Information Model and the concrete working of Aggregates are defined in IEC 62541-13.
Conventions for Historical Access Clients are informatively provided in Annex A.

IEC 62541-3: 2025 describes the OPC Unified Architecture (OPC UA) AddressSpace and its Objects. This specification is the OPC UA meta model on which OPC UA information models are based. This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) addition of the concept and modelling elements for Interfaces and AddIns;
b) addition of Currency;
c) addition of Method Meta Data to define additional attributes for Method Arguments;
d) addition of ApplyRestrictionToBrowse bit to AccessRestrictionType;
e) addition of a Non-Volatile Storage bit to AccessLevelExType;
f) addition of a Constant bit and ConfigurationConstant bit to AccessLevelExType;
g) the View NodeClass has been changed to define the EventNotifier as an EventNotifierType in the same way the Object NodeClass defines it;
h) correctition of HasNotifier, HasEventSource, and Organizes, to include ObjectType as valid source node;
i) NamingRules have become deprecated;
j) addition of AssociatedWith ReferenceType.

IEC 62541-11: 2025 defines the Information Model associated with Historical Access (HA). It particularly includes additional and complementary descriptions of the NodeClasses and Attributes needed for Historical Access, additional standard Properties, and other information and behaviour. The complete AddressSpace Model including all NodeClasses and Attributes is specified in IEC 62541‑3. The predefined Information Model is defined in IEC 62541‑5. The Services to detect and access historical data and events, and description of the ExtensibleParameter types are specified in IEC 62541‑4. This document includes functionality to compute and return Aggregates like minimum, maximum, average etc. The Information Model and the concrete working of Aggregates are defined in IEC 62541‑13. Conventions for Historical Access Clients are informatively provided in Annex A. This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) a functionality has been added to support retrieving of modified events; b) an Event has been added to indicate when a backfill occurred; c) a new ReferenceType that can be used to indicate an external node has been defined; d) the text has been improved to better explain the concept of annotation and remove conflicting explanations; e) a default historian configuration (and where to find it) has been defined; f) HistoricalEventConfigurationType, which provides general configuration information about the historical Event storage, has been added; g) the text has been updated and optional fields have been added to HA configuration object to allow configuration to be defined for periodic data collection, not just for exception-based collection; h) an ObjectType that can be used for external event collection has been provided as well as an example how historians can be configured.

IEC 62541-3: 2025 describes the OPC Unified Architecture (OPC UA) AddressSpace and its Objects. This specification is the OPC UA meta model on which OPC UA information models are based. This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) addition of the concept and modelling elements for Interfaces and AddIns; b) addition of Currency; c) addition of Method Meta Data to define additional attributes for Method Arguments; d) addition of ApplyRestrictionToBrowse bit to AccessRestrictionType; e) addition of a Non-Volatile Storage bit to AccessLevelExType; f) addition of a Constant bit and ConfigurationConstant bit to AccessLevelExType; g) the View NodeClass has been changed to define the EventNotifier as an EventNotifierType in the same way the Object NodeClass defines it; h) correctition of HasNotifier, HasEventSource, and Organizes, to include ObjectType as valid source node; i) NamingRules have become deprecated; j) addition of AssociatedWith ReferenceType.

IEC 62541-5:2026 This edition includes the following significant technical changes with respect to the previous edition: a) Annex B has been removed and used to create IEC 62451-16; b) Annex C has been removed and used to create IEC 62451-20; c) currency information model has been added; d) information model for Interfaces and AddIns has been added; e) information model for Method Metadata has been added; f) MaxSessions, MaxSubscriptions, and MaxMonitoredItems have been added to capabilities; g) information model for ordered list of objects has been added; h) PortableQualifiedName and PortableNodeId DataTypes have been added; i) UriString DataType has been added; j) SemanticVersionString DataType has been added; k) AssociatedWith Reference Type has been added; l) ConfigurationVersion Property has been added to NamespaceMetadataType; m) AuditClientEventType and AuditClientUpdateMethodResultEventType have been added; n) ModelVersion has been added to NamespaceMetadataType; o) NoTransparentBackupRedundancyType has been added to support a Primary/Standby use case; p) BitFieldType and BitFieldDefinitionType have been added. This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision.

IEC 62541-6:2025 specifies the mapping between the security model described in IEC 62541‑2, the abstract service definitions specified in IEC 62541‑4, the data structures defined in IEC 62541‑5 and the physical network protocols that can be used to implement the OPC UA specification. This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) addition of support for ECC to UA Secure Conversation; b) use of the AuthorityKeyIdentifier extension in Certificate Revocation Lists; c) enhancement of JSON mapping of Unions; d) addition of Decimal data type encoding. e) description of ECC keyUsage rules; f) addition of Media assigned by IANA to UANodeSet definition; g) addition of requirements for user and issuer Certificates; h) addition of rules which specify what happens when DateTime precision is lost; i) addition of rules to allow for the truncation of strings containing embedded nulls. J) definition of a normative string representation for NodeId, ExpandedNodeId and QualifiedName for JSON mapping. k) requirement that TAI times be converted to UTC; l) new possibility to omit Symbol if unknown in JSON encoding; m) addition of fields needed to support RolePermissions to the UANodeSet

IEC 62541-8:2025 defines the information model associated with Data Access (DA). It particularly includes additional VariableTypes and complementary descriptions of the NodeClasses and Attributes needed for Data Access, additional Properties, and other information and behaviour. The complete address space model, including all NodeClasses and Attributes is specified in IEC 62541‑3. The services to detect and access data are specified in IEC 62541‑4. Annex A specifies how the information received from OPC COM Data Access (DA) Servers is mapped to the Data Access model. This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) addition of a "Quantity Model" which can be referenced from EngineeringUnit Properties. The model defines quantities and assigned units. In addition it provides alternative units and the conversion to them. b) addition of rules for ValuePrecision Property: - can also be used for other subtypes like Duration and Decimal. - rules have been added when ValuePrecision has negative values.

IEC 62351-7:2025 defines network and system management (NSM) data object models that are specific to power system operations. These NSM data objects will be used to monitor the health of networks and systems, to detect possible security intrusions, and to manage the performance and reliability of the information infrastructure. The goal is to define a set of abstract objects that will allow the remote monitoring of the health and condition of IEDs (Intelligent Electronic Devices), RTUs (Remote Terminal Units), DERs (Distributed Energy Resources) systems and other systems that are important to power system operations.
Power systems operations are increasingly reliant on information infrastructures, including communication networks, IEDs, and self-defining communication protocols. Therefore, management of the information infrastructure has become crucial to providing the necessary high levels of security and reliability in power system operations.
The telecommunication infrastructure that is in use for the transport of telecontrol and automation protocols is already subject to health and condition monitoring control, using the concepts developed in the IETF Simple Network Management Protocol (SNMP) standards for network management. However, power system specific devices (like teleprotection, telecontrol, substation automation, synchrophasors, inverters and protections) need instead a specific solution for monitoring their health.
The NSM objects provide monitoring data for IEC protocols used for power systems (IEC 61850, IEC 60870-5-104) and device specific environmental and security status. As a derivative of IEC 60870-5-104, IEEE 1815 DNP3 is also included in the list of monitored protocols. The NSM data objects use the naming conventions developed for IEC 61850, expanded to address NSM issues. For the sake of generality these data objects, and the data types of which they are comprised, are defined as abstract models of data objects.
In addition to the abstract model, in order to allow the integration of the monitoring of power system devices within the NSM environment in this part of IEC 62351, a mapping of objects to the SNMP protocol of Management Information Base (MIBs) is provided.
The objects that are already covered by existing MIBs are not defined here but are expected to be compliant with existing MIB standards. For example protocols including EST, SCEP, RADIUS, LDAP, GDOI are not in scope.
This edition of IEC 62351-7 cancels and replaces IEC 62351-7 published in 2017. This new edition constitutes a technical revision and includes the following significant technical changes with respect to IEC 62351-7:
a) Reviewed and enriched the NSM object data model;
b) UML model adopted for NSM objects description;
c) SNMP protocol MIBs translation included as Code Components

IEC 62541-4:2025 is available as IEC 62541-4:2025 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 62541-4:2025 defines the OPC Unified Architecture (OPC UA) Services. The Services defined are the collection of abstract Remote Procedure Calls (RPC) that are implemented by OPC UA Servers and called by OPC UA Clients. All interactions between OPC UA Clients and Servers occur via these Services. The defined Services are considered abstract because no particular RPC mechanism for implementation is defined in this document. IEC 62541‑6 specifies one or more concrete mappings supported for implementation. For example, one mapping in IEC 62541‑6 is to UA-TCP UA-SC UA-Binary. In that case the Services described in this document appear as OPC UA Binary encoded payload, secured with OPC UA Secure Conversation and transported via OPC UA TCP. Not all OPC UA Servers implement all of the defined Services. IEC 62541‑7 defines the Profiles that dictate which Services must be implemented in order to be compliant with a particular Profile. A BNF (Backus-Naur form) for browse path names is described in Annex A. This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) addition of new definitions to Method Call Service to allow optional Method arguments; b)addition of reference to SystemStatusChangeEventType for event monitored item error scenarios; c) enhancement of the general description of how determining if a Certificate is trusted; d) addition of support for ECC; e) addition of revisedAggregateConfiguration to AggregateFilterResult structure; f) addition of INVALID to the BrowseDirection enumeration data type; g) addition of INVALID to the TimestampsToReturn enumeration data type; h) addition of definitions that make sure the subscription functionality works if retransmission queues are optional; i) addition of client checks has been added to be symmetric to the Server Certificate check has been added; j) clarification that ‘local’ top level domain is not appended by server into certificate and not checked by client when returned from LDS-ME; k) addition of a definition for expiration behaviour of IssuedIdentityTokens; l) addition of status code Good_PasswordChangeRequired to ActivateSession; m) restriction of AdditionalInfo to servers in debug mode; n) addition of new status code Bad_ServerTooBusy; o) addition of definition for cases where server certificate must be contained in GetEndpoints response.

IEC 62541-13:2025 is available as IEC 62541-13:2025 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 62541-13:2025 defines the information model associated with Aggregates. Programmatically produced aggregate examples are listed in Annex A. This third edition cancels and replaces the second edition published in 2020. This edition constitutes a technical revision. This edition includes the following technical changes with respect to the previous edition: a) Multiple fixes for the computation of aggregates • The Raw status bit is always set for non-bad StatusCodes for the Start and End aggregates. • Entries in the Interpolative examples Tables A2.2 Historian1, Historian2, and Historian3 have been changed from Good to Good, Raw status codes when the timestamp matches with the timestamp of the data source. • Missing tables have been added for DurationInStateZero and DurationInStateNonZero. • The value of zero has been removed for results with a StatusCode of bad. • Data Type was listed as "Status Code" when it is "Double" for both Standard Deviation and both Variance Aggregates. • Rounding Error in TimeAverage and TimeAverage2 have been corrected. • The status codes have been corrected for the last two intervals and the value has been corrected in the last interval. • The wording has been changed to be more consistent with the certification testing tool. • UsedSlopedExtrapolation set to true for Historian2 and all examples locations needed new values or status' are modified. • Values affected by percent good and percent bad have been updated. • PercentGood/PercentBad are now accounted for in the calculation. • TimeAverage uses SlopedInterpolation but the Time aggregate is incorrectly allowed to used Stepped Interpolation. • Partial bit is now correctly calculated. • Unclear sentence was removed. • Examples have been moved to a CSV. • The value and status code for Historian 3 have been updated. • TimeAverage2 Historian1 now takes uncertain regions into account when calculating StatusCodes. • TimeAverage2 Historian2 now takes uncertain regions into account when calculating StatusCodes. • Total2 Historian1 now takes uncertain regions into account when calculating StatusCodes • Total2 Historian2 now takes uncertain regions into account when calculating StatusCodes • Maximum2 Historian1 now takes uncertain regions into account when calculating StatusCodes • MaximumActualTime2 Historian1 now takes uncertain regions into account when calculating StatusCodes • Minimum2 Historian1 now takes uncertain regions into account when calculating StatusCodes • MinimumActualTime2 Historian1 now has the StatusCodes calculated while using the TreatUncertainAsBad flag. • Range2 Historian1 now looks at TreatUncertainAsBad in the calculation of the StatusCodes. • Clarifications have been made to the text defining how PercentGood/PercentBad are used. The table values and StatusCodes of the TimeAverage2 and Total2 aggregates have been corrected.

IEC 62541-100:2025 defines the information model associated with Devices. This document describes three models which build upon each other as follows: • The (base) Device Model is intended to provide a unified view of devices and their hardware and software parts irrespective of the underlying device protocols. • The Device Communication Model adds Network and Connection information elements so that communication topologies can be created. • The Device Integration Host Model finally adds additional elements and rules required for host systems to manage integration for a complete system. It enables reflecting the topology of the automation system with the devices as well as the connecting communication networks. This document also defines AddIns that can be used for the models in this document but also for models in other information models. They are: • Locking model – a generic AddIn to control concurrent access, • Software update model – an AddIn to manage software in a Device. This second edition cancels and replaces the first edition published in 2015. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a a ComponentType that can be used to model any HW or SW element of a device has been defined and a SoftwareType has been added as subtype of ComponentType; b the new OPC UA interface concept and defined interfaces for Nameplate, DeviceHealth, and SupportInfo has been added. c) a new model for Software Update (Firmware Update) has been added; d) a new entry point for documents where each document is represented by a FileType instance has been specified; e) a model that provides information about the lifetime, related limits and semantic of the lifetime of things like tools, material or machines has been added.

IEC 62541-7: 2025 specifies value and structure of Profiles in the OPC Unified Architecture. OPC UA Profiles are used to segregate features with regard to testing of OPC UA products and the nature of the testing. The scope of this document includes defining functionality that can only be tested. The definition of actual TestCases is not within the scope of this document, but the general categories of TestCases are covered by this document. Most OPC UA applications will conform to several, but not all of the Profiles. This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) Profiles and ConformanceUnits are not part of this document, but are solely managed in a public database as described in Clause 1.

IEC 62541-10:2025 is available as IEC 62541-10:2025 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 62541-10:2025 defines the Information Model associated with Programs in OPC Unified Architecture (OPC UA). This includes the description of the NodeClasses, standard Properties, Methods and Events and associated behaviour and information for Programs. The complete AddressSpace model including all NodeClasses and Attributes is specified in IEC 62541-3. The Services such as those used to invoke the Methods used to manage Programs are specified in IEC 62541-4. An example for a DomainDownload Program is defined in Annex A. This fourth edition cancels and replaces the third edition published in 2020. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - StateMachine table format has been aligned.

IEC 62351-7:2025 defines network and system management (NSM) data object models that are specific to power system operations. These NSM data objects will be used to monitor the health of networks and systems, to detect possible security intrusions, and to manage the performance and reliability of the information infrastructure. The goal is to define a set of abstract objects that will allow the remote monitoring of the health and condition of IEDs (Intelligent Electronic Devices), RTUs (Remote Terminal Units), DERs (Distributed Energy Resources) systems and other systems that are important to power system operations. Power systems operations are increasingly reliant on information infrastructures, including communication networks, IEDs, and self-defining communication protocols. Therefore, management of the information infrastructure has become crucial to providing the necessary high levels of security and reliability in power system operations. The telecommunication infrastructure that is in use for the transport of telecontrol and automation protocols is already subject to health and condition monitoring control, using the concepts developed in the IETF Simple Network Management Protocol (SNMP) standards for network management. However, power system specific devices (like teleprotection, telecontrol, substation automation, synchrophasors, inverters and protections) need instead a specific solution for monitoring their health. The NSM objects provide monitoring data for IEC protocols used for power systems (IEC 61850, IEC 60870-5-104) and device specific environmental and security status. As a derivative of IEC 60870-5-104, IEEE 1815 DNP3 is also included in the list of monitored protocols. The NSM data objects use the naming conventions developed for IEC 61850, expanded to address NSM issues. For the sake of generality these data objects, and the data types of which they are comprised, are defined as abstract models of data objects. In addition to the abstract model, in order to allow the integration of the monitoring of power system devices within the NSM environment in this part of IEC 62351, a mapping of objects to the SNMP protocol of Management Information Base (MIBs) is provided. The objects that are already covered by existing MIBs are not defined here but are expected to be compliant with existing MIB standards. For example protocols including EST, SCEP, RADIUS, LDAP, GDOI are not in scope. This edition of IEC 62351-7 cancels and replaces IEC 62351-7 published in 2017. This new edition constitutes a technical revision and includes the following significant technical changes with respect to IEC 62351-7: a) Reviewed and enriched the NSM object data model; b) UML model adopted for NSM objects description; c) SNMP protocol MIBs translation included as Code Components

IEC 61000-4-2: 2025 relates to the immunity requirements and test methods for electrical and electronic equipment subjected to static electricity discharges from operators directly and from personnel to adjacent objects. It additionally specifies ranges of test levels which relate to different environmental, and installation conditions and establishes test procedures. The objective of this document is to establish a common and reproducible basis for evaluating the performance of electrical and electronic equipment when subjected to electrostatic discharges. In addition, it includes electrostatic discharges which can occur from personnel to objects near the equipment. This document specifies:
- ideal waveform of the discharge current;
- range of test levels;
- test equipment;
- test setup;
- test procedure;
- calibration procedure;
- measurement uncertainty.
This document gives specifications for tests performed in laboratories and guidance to post-installation tests. This document is not intended to specify the tests to be applied to particular apparatus or systems. The main aim is to give a general basic reference to all concerned product committees. The product committees remain responsible for the appropriate choice of the tests and the severity level to be applied to their equipment. This document excludes tests intended to evaluate the ESD sensitivity of devices during handling and packaging. It is not intended for use in characterizing the performance of ESD protection circuit IEC Guide 107.
This document forms Part 4-2 of IEC 61000. It has the status of a basic EMC publication in accordance with IEC Guide 107. This third edition cancels and replaces the second edition published in 2008. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) added a calibration requirement for ESD generators with air discharge tip;
b) added a normative annex for test setups for particular kind of equipment (see Annex I);
c) added an informative annex for wearable devices (see Annex J);
d) added an informative annex on how to select test points and give guidance on how to specify the number of pulses for direct contact discharges (see Annex E);
e) moved Clause 9 into a new informative annex (see Annex K);
f) improvement of the current calibration procedure;
g) improvement of the measurement uncertainty considerations with examples of uncertainty budgets;
h) because post-installation tests cannot be performed in a controlled environment, this test method has been moved into a new informative Annex G.

IEC 61000-4-2: 2025 relates to the immunity requirements and test methods for electrical and electronic equipment subjected to static electricity discharges from operators directly and from personnel to adjacent objects. It additionally specifies ranges of test levels which relate to different environmental, and installation conditions and establishes test procedures. The objective of this document is to establish a common and reproducible basis for evaluating the performance of electrical and electronic equipment when subjected to electrostatic discharges. In addition, it includes electrostatic discharges which can occur from personnel to objects near the equipment. This document specifies: - ideal waveform of the discharge current; - range of test levels; - test equipment; - test setup; - test procedure; - calibration procedure; - measurement uncertainty. This document gives specifications for tests performed in laboratories and guidance to post-installation tests. This document is not intended to specify the tests to be applied to particular apparatus or systems. The main aim is to give a general basic reference to all concerned product committees. The product committees remain responsible for the appropriate choice of the tests and the severity level to be applied to their equipment. This document excludes tests intended to evaluate the ESD sensitivity of devices during handling and packaging. It is not intended for use in characterizing the performance of ESD protection circuit IEC Guide 107. This document forms Part 4-2 of IEC 61000. It has the status of a basic EMC publication in accordance with IEC Guide 107. This third edition cancels and replaces the second edition published in 2008. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) added a calibration requirement for ESD generators with air discharge tip; b) added a normative annex for test setups for particular kind of equipment (see Annex I); c) added an informative annex for wearable devices (see Annex J); d) added an informative annex on how to select test points and give guidance on how to specify the number of pulses for direct contact discharges (see Annex E); e) moved Clause 9 into a new informative annex (see Annex K); f) improvement of the current calibration procedure; g) improvement of the measurement uncertainty considerations with examples of uncertainty budgets; h) because post-installation tests cannot be performed in a controlled environment, this test method has been moved into a new informative Annex G.

IEC 61000-2-4:2024 is available as IEC 61000-2-4:2024 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

IEC 61000-2-4:2024 is related to conducted disturbances in the frequency range from 0 kHz to 150 kHz. It gives compatibility levels in differential mode (L-L and L-N) for industrial locations, with a nominal voltage up to 35 kV and a nominal frequency of 50 Hz or 60 Hz.
NOTE 1 Industrial locations are defined in 3.1.8.
Power distribution systems on ships, aircraft, offshore platforms and railways are not included.
NOTE 2 See also Annex E. The compatibility levels specified in this document apply at the in-plant point of coupling (IPC). The level of the low-frequency disturbances at the terminals of equipment receiving its supply from the IPC is generally assumed to be similar to the disturbance level at the IPC itself. However, in some situations this is not the case, particularly when a long feeder is dedicated to the supply of a particular load, or when a disturbance is generated or amplified within the installation of which the equipment forms a part.
Compatibility levels are specified for the types of low-frequency electromagnetic disturbances expected at any in-plant point of coupling (IPC) within industrial locations, for guidance in the definition of:
a) limits for disturbance emissions in industrial power distribution systems (including the planning levels defined in 3.1.5);
NOTE 3 A very wide range of conditions is possible in the electromagnetic environments of industrial networks. These are approximated in this document by the three classes described in Clause 4. However, it is the responsibility of the operator of such a network to take account of the particular electromagnetic and economic conditions, including equipment characteristics, in setting the above-mentioned limits.
b) immunity levels for the equipment within these systems.
The disturbance phenomena considered are:
- voltage deviations;
- voltage dips and short interruptions;
- voltage imbalance;
- power-frequency variations;
- harmonics up to order 40;
- interharmonics up to the 40th harmonic;
- voltage components above the 40th harmonic up to 150 kHz;
- DC component;
- transient overvoltages.
The compatibility levels are given for different classes of environment determined by the characteristics of the supply network and loads.
NOTE 4 Compatibility levels at the point of common coupling (PCC) on public networks are specified in IEC 61000‑2‑2 for low-voltage networks and IEC 61000‑2‑12 for medium-voltage networks. IEC TR 61000‑3‑6 and IEC TR 61000‑3‑7 describe the approach of power distribution system operators to the limitation of emissions from installations and large loads.
This third edition cancels and replaces the second edition published in 2002. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) introduction of new classes 2a, 2b and 2L (former class 2);
b) modification of existing compatibility levels for class 3;
c) addition of compatibility levels in the frequency range 2 kHz to 150 kHz;
d) addition of compatibility levels using a new quantity: partial weighted harmonic distortion (PWHD).

IEC 61968-9:2024 specifies the information content of a set of message types that can be used to support many of the business functions related to meter reading and control. Typical uses of the message types include meter reading, controls, events, customer data synchronization and customer switching. Although intended primarily for electrical distribution networks, IEC 61968-9 can be used for other metering applications, including non-electrical metered quantities necessary to support gas and water networks.
The purpose of this document is to define a standard for the integration of metering systems (MS), which includes traditional manual systems, and (one or two-way) automated meter reading (AMR) systems, and meter data management (MDM) systems with other enterprise systems and business functions within the scope of IEC 61968. The scope of this document is the exchange of information between metering systems, MDM systems and other systems within the utility enterprise. The specific details of communication protocols those systems employ are outside the scope of this document. Instead, this document will recognize and model the general capabilities that can be potentially provided by advanced and/or legacy meter infrastructures, including two-way communication capabilities such as load control, dynamic pricing, outage detection, distributed energy resource (DER) control signals and on-request read. In this way, this document will not be impacted by the specification, development and/or deployment of next generation meter infrastructures either through the use of standards or proprietary means.
The focus of IEC 61968-9 is to define standard messages for the integration of enterprise applications, these messages may be directly or indirectly related to information flows within a broader scope. Examples would include messaging between head end systems and meters or PAN devices. The various components described later in this document will typically fall into either the category of a metering system (MS) head end, an MDM or other enterprise application (e.g. OMS, DRMS, CIS).
The capabilities and information provided by a meter reading and meter data management systems are important for a variety of purposes, including (but not limited to) interval data, time-based demand data, time-based energy data (usage and production), outage management, service interruption, service restoration, quality of service monitoring, distribution network analysis, distribution planning, demand response, customer billing and work management. This standard also extends the CIM (Common Information Model) to support the exchange of meter data.
This third edition cancels and replaces the second edition published in 2013. This edition constitutes a technical revision. Please see the foreword of IEC 61968-9 for further details.

IEC 61000-2-4:2024 is available as IEC 61000-2-4:2024 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 61000-2-4:2024 is related to conducted disturbances in the frequency range from 0 kHz to 150 kHz. It gives compatibility levels in differential mode (L-L and L-N) for industrial locations, with a nominal voltage up to 35 kV and a nominal frequency of 50 Hz or 60 Hz. NOTE 1 Industrial locations are defined in 3.1.8. Power distribution systems on ships, aircraft, offshore platforms and railways are not included. NOTE 2 See also Annex E. The compatibility levels specified in this document apply at the in-plant point of coupling (IPC). The level of the low-frequency disturbances at the terminals of equipment receiving its supply from the IPC is generally assumed to be similar to the disturbance level at the IPC itself. However, in some situations this is not the case, particularly when a long feeder is dedicated to the supply of a particular load, or when a disturbance is generated or amplified within the installation of which the equipment forms a part. Compatibility levels are specified for the types of low-frequency electromagnetic disturbances expected at any in-plant point of coupling (IPC) within industrial locations, for guidance in the definition of: a) limits for disturbance emissions in industrial power distribution systems (including the planning levels defined in 3.1.5); NOTE 3 A very wide range of conditions is possible in the electromagnetic environments of industrial networks. These are approximated in this document by the three classes described in Clause 4. However, it is the responsibility of the operator of such a network to take account of the particular electromagnetic and economic conditions, including equipment characteristics, in setting the above-mentioned limits. b) immunity levels for the equipment within these systems. The disturbance phenomena considered are: - voltage deviations; - voltage dips and short interruptions; - voltage imbalance; - power-frequency variations; - harmonics up to order 40; - interharmonics up to the 40th harmonic; - voltage components above the 40th harmonic up to 150 kHz; - DC component; - transient overvoltages. The compatibility levels are given for different classes of environment determined by the characteristics of the supply network and loads. NOTE 4 Compatibility levels at the point of common coupling (PCC) on public networks are specified in IEC 61000‑2‑2 for low-voltage networks and IEC 61000‑2‑12 for medium-voltage networks. IEC TR 61000‑3‑6 and IEC TR 61000‑3‑7 describe the approach of power distribution system operators to the limitation of emissions from installations and large loads. This third edition cancels and replaces the second edition published in 2002. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) introduction of new classes 2a, 2b and 2L (former class 2); b) modification of existing compatibility levels for class 3; c) addition of compatibility levels in the frequency range 2 kHz to 150 kHz; d) addition of compatibility levels using a new quantity: partial weighted harmonic distortion (PWHD).

IEC 61968-9:2024 specifies the information content of a set of message types that can be used to support many of the business functions related to meter reading and control. Typical uses of the message types include meter reading, controls, events, customer data synchronization and customer switching. Although intended primarily for electrical distribution networks, IEC 61968-9 can be used for other metering applications, including non-electrical metered quantities necessary to support gas and water networks. The purpose of this document is to define a standard for the integration of metering systems (MS), which includes traditional manual systems, and (one or two-way) automated meter reading (AMR) systems, and meter data management (MDM) systems with other enterprise systems and business functions within the scope of IEC 61968. The scope of this document is the exchange of information between metering systems, MDM systems and other systems within the utility enterprise. The specific details of communication protocols those systems employ are outside the scope of this document. Instead, this document will recognize and model the general capabilities that can be potentially provided by advanced and/or legacy meter infrastructures, including two-way communication capabilities such as load control, dynamic pricing, outage detection, distributed energy resource (DER) control signals and on-request read. In this way, this document will not be impacted by the specification, development and/or deployment of next generation meter infrastructures either through the use of standards or proprietary means. The focus of IEC 61968-9 is to define standard messages for the integration of enterprise applications, these messages may be directly or indirectly related to information flows within a broader scope. Examples would include messaging between head end systems and meters or PAN devices. The various components described later in this document will typically fall into either the category of a metering system (MS) head end, an MDM or other enterprise application (e.g. OMS, DRMS, CIS). The capabilities and information provided by a meter reading and meter data management systems are important for a variety of purposes, including (but not limited to) interval data, time-based demand data, time-based energy data (usage and production), outage management, service interruption, service restoration, quality of service monitoring, distribution network analysis, distribution planning, demand response, customer billing and work management. This standard also extends the CIM (Common Information Model) to support the exchange of meter data. This third edition cancels and replaces the second edition published in 2013. This edition constitutes a technical revision. Please see the foreword of IEC 61968-9 for further details.

This document applies to electrical equipment using signals in the frequency range 3 kHz to 95 kHz to transmit or receive information on low voltage electrical systems, for electricity suppliers and distributors.
Mains communicating equipment (MCE) may fall into one of the two following categories:
-   MCE implementing transmission or reception of information on LV distribution networks or installations of network users connected to the public electricity distribution network as the sole function. Immunity requirements for such equipment are entirely covered by this document;
-   MCE being equipment covered by the scope of other standards, integrating mains communication as one of their functions. In this case, only the immunity requirements for the mains communication function of such equipment are covered by the scope of this document. Immunity requirements for all other available functions of this equipment are covered by the relevant product standard or generic standard.
The object of this document is to contribute to ensuring EMC in general. It specifies essential immunity requirements and test methods, including those tests which are to be performed during type-testing of MCE, for electromagnetic interference (EMI) generated on LV installations.
It defines the methods and requirements for testing immunity of MCE on meeting the essential requirements of the EMCD. Test requirements are specified for each port considered.
Furthermore, it provides guidelines for the assessment of the performance of the communication function of an MCE. Normative specifications are under consideration.
This document gives immunity requirements which are applicable to MCE used by electricity suppliers and distributors (e.g. DSOs) for purposes like energy management and network monitoring and automation. The levels do not however cover extreme cases which could occur in any location but with a low probability of occurrence. In special cases situations will arise where the level of disturbances could exceed the levels specified in this document, e.g. where a hand-held transmitter is used in proximity of an apparatus. In these instances special mitigation measures might have to be employed.
It does not specify immunity of MCE to signals from other MCE operating in the same nominal frequency band or immunity to signals originating from power line carrier systems operating on high or medium-voltage networks.
Safety considerations are not included in this document.

IEC 61970-302:2024 specifies a Dynamics package which contains part of the CIM to support the exchange of models between software applications that perform analysis of the steady-state stability (small-signal stability) or transient stability of a power system as defined by IEEE / CIGRE, Definition and classification of power system stability IEEE/CIGRE joint task force on stability terms and definitions.
The model descriptions in this document provide specifications for each type of dynamic model as well as the information that needs to be included in dynamic case exchanges between planning/study applications.
The scope of the CIM Dynamics package specified in this document includes:
• standard models: a simplified approach to describing dynamic models, where models representing dynamic behaviour of elements of the power system are contained in predefined libraries of classes which are interconnected in a standard manner. Only the names of the selected elements of the models along with their attributes are needed to describe dynamic behaviour.
• proprietary user-defined models: an approach providing users the ability to define the parameters of a dynamic behaviour model representing a vendor or user proprietary device where an explicit description of the model is not provided by this document. The same libraries and standard interconnections are used for both proprietary user-defined models and standard models. The behavioural details of the model are not documented in this document, only the model parameters.
• A model to enable exchange of models’ descriptions. This approach can be used to describe user defined and standard models.
• A model to enable exchange of simulation results.
This second edition cancels and replaces the first edition published in 2018. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) The majority of issues detected in IEC 61970-302:2018 are addressed;
b) IEEE 421.5-2016 on Excitation systems is fully covered;
c) The IEEE turbine report from 2013 was considered and as a result a number of gas, steam and hydro turbines/governors are added;
d) IEC 61400-27-1:2020 on wind turbines is fully incorporated;
e) WECC Inverter-Based Resource (IBR) models, Hybrid STATCOM models and storage models are added;
f) The user defined models are enhanced with a model which enables modelling of detailed dynamic model;
g) A model to enable exchange of simulation results is added;
h) The work on the HVDC models is not complete. The HVDC dynamics models are a complex domain in which there are no models that are approved or widely recognised on international level, i.e. there are only project-based models. At this stage IEC 61970-302:2022 only specifies some general classes. However, it is recognised that better coverage of HVDC will require a further edition of this document;
i) Models from IEEE 1547-2018 "IEEE Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces" are added.
j) Statements have been added to certain figures, tables, schemas, and enumerations throughout the document that indicate that they are reproduced with the permission of the UCA International User Group (UCAIug). These items are derived from the CIM.

IEC 61970-302:2024 specifies a Dynamics package which contains part of the CIM to support the exchange of models between software applications that perform analysis of the steady-state stability (small-signal stability) or transient stability of a power system as defined by IEEE / CIGRE, Definition and classification of power system stability IEEE/CIGRE joint task force on stability terms and definitions. The model descriptions in this document provide specifications for each type of dynamic model as well as the information that needs to be included in dynamic case exchanges between planning/study applications. The scope of the CIM Dynamics package specified in this document includes: • standard models: a simplified approach to describing dynamic models, where models representing dynamic behaviour of elements of the power system are contained in predefined libraries of classes which are interconnected in a standard manner. Only the names of the selected elements of the models along with their attributes are needed to describe dynamic behaviour. • proprietary user-defined models: an approach providing users the ability to define the parameters of a dynamic behaviour model representing a vendor or user proprietary device where an explicit description of the model is not provided by this document. The same libraries and standard interconnections are used for both proprietary user-defined models and standard models. The behavioural details of the model are not documented in this document, only the model parameters. • A model to enable exchange of models’ descriptions. This approach can be used to describe user defined and standard models. • A model to enable exchange of simulation results. This second edition cancels and replaces the first edition published in 2018. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) The majority of issues detected in IEC 61970-302:2018 are addressed; b) IEEE 421.5-2016 on Excitation systems is fully covered; c) The IEEE turbine report from 2013 was considered and as a result a number of gas, steam and hydro turbines/governors are added; d) IEC 61400-27-1:2020 on wind turbines is fully incorporated; e) WECC Inverter-Based Resource (IBR) models, Hybrid STATCOM models and storage models are added; f) The user defined models are enhanced with a model which enables modelling of detailed dynamic model; g) A model to enable exchange of simulation results is added; h) The work on the HVDC models is not complete. The HVDC dynamics models are a complex domain in which there are no models that are approved or widely recognised on international level, i.e. there are only project-based models. At this stage IEC 61970-302:2022 only specifies some general classes. However, it is recognised that better coverage of HVDC will require a further edition of this document; i) Models from IEEE 1547-2018 "IEEE Standard for Interconnection and Interoperability of Distributed Energy Resources with Associated Electric Power Systems Interfaces" are added. j) Statements have been added to certain figures, tables, schemas, and enumerations throughout the document that indicate that they are reproduced with the permission of the UCA International User Group (UCAIug). These items are derived from the CIM.

This part of IEC 62056 specifies the overall structure of the OBject Identification System (OBIS) and the mapping of all commonly used data items in metering equipment to their identification codes.
OBIS provides a unique identifier for all data within the metering equipment, including not only measurement values, but also abstract values used for configuration or obtaining information about the behaviour of the metering equipment. The ID codes defined in this document are used for the identification of:
- logical names of the various instances of the ICs, or objects, as defined in IEC 62056-6-2:2021;
- data transmitted through communication lines;
- data displayed on the metering equipment, see Clause A.2.
This document applies to all types of metering equipment, such as fully integrated meters, modular meters, tariff attachments, data concentrators, etc.
To cover metering equipment measuring energy types other than electricity, combined metering equipment measuring more than one type of energy or metering equipment with several physical measurement channels, the concepts of medium and channels are introduced. This allows meter data originating from different sources to be identified. While this document fully defines the structure of the identification system for other media, the mapping of non-electrical energy related data items to ID codes is completed separately.
NOTE EN 13757-1:2014 defines identifiers for metering equipment other than electricity: heat cost allocators, thermal energy, gas, cold water and hot water.

This part of IEC 62056 specifies the overall structure of the OBject Identification System (OBIS) and the mapping of all commonly used data items in metering equipment to their identification codes. OBIS provides a unique identifier for all data within the metering equipment, including not only measurement values, but also abstract values used for configuration or obtaining information about the behaviour of the metering equipment. The ID codes defined in this document are used for the identification of: - logical names of the various instances of the ICs, or objects, as defined in IEC 62056-6-2:2021; - data transmitted through communication lines; - data displayed on the metering equipment, see Clause A.2. This document applies to all types of metering equipment, such as fully integrated meters, modular meters, tariff attachments, data concentrators, etc. To cover metering equipment measuring energy types other than electricity, combined metering equipment measuring more than one type of energy or metering equipment with several physical measurement channels, the concepts of medium and channels are introduced. This allows meter data originating from different sources to be identified. While this document fully defines the structure of the identification system for other media, the mapping of non-electrical energy related data items to ID codes is completed separately. NOTE EN 13757-1:2014 defines identifiers for metering equipment other than electricity: heat cost allocators, thermal energy, gas, cold water and hot water.

IEC 61158-2:2023 is one of a series produced to facilitate the interconnection of automation system components. It is related to other standards in the set as defined by the "three-layer" fieldbus reference model described in IEC 61158‑1.

This part of IEC 62056 specifies the DLMS®/COSEM application layer in terms of structure, services and protocols for DLMS®/COSEM clients and servers, and defines rules to specify the DLMS®/COSEM communication profiles.
It defines services for establishing and releasing application associations, and data communication services for accessing the methods and attributes of COSEM interface objects, defined in IEC 62056-6-2:2021 using either logical name (LN) or short name (SN) referencing.
Annex A (normative) defines how to use the COSEM application layer in various communication profiles. It specifies how various communication profiles can be constructed for exchanging data with metering equipment using the COSEM interface model, and what are the necessary elements to specify in each communication profile. The actual, media-specific communication profiles are specified in separate parts of the IEC 62056 series.
Annex B (normative) specifies the SMS short wrapper.
Annex C (normative) specifies the gateway protocol.
Annex D, Annex E and Annex F (informative) include encoding examples for APDUs.
Annex G (normative) provides NSA Suite B elliptic curves and domain parameters.
Annex H (informative) provides an example of an End entity signature certificate using P-256 signed with P-256.
Annex I (normative) specifies the use of key agreement schemes in DLMS®/COSEM.
Annex J (informative) provides examples of exchanging protected xDLMS APDUs between a third party and a server.
Annex K (informative) lists the main technical changes in this edition of the standard.

This part of IEC 62056 specifies a model of a meter as it is seen through its communication interface(s). Generic building blocks are defined using object-oriented methods, in the form of interface classes to model meters from simple up to very complex functionality.
Annexes A to F (informative) provide additional information related to some interface classes.

This part of IEC 62056 specifies the DLMS®/COSEM application layer in terms of structure, services and protocols for DLMS®/COSEM clients and servers, and defines rules to specify the DLMS®/COSEM communication profiles. It defines services for establishing and releasing application associations, and data communication services for accessing the methods and attributes of COSEM interface objects, defined in IEC 62056-6-2:2021 using either logical name (LN) or short name (SN) referencing. Annex A (normative) defines how to use the COSEM application layer in various communication profiles. It specifies how various communication profiles can be constructed for exchanging data with metering equipment using the COSEM interface model, and what are the necessary elements to specify in each communication profile. The actual, media-specific communication profiles are specified in separate parts of the IEC 62056 series. Annex B (normative) specifies the SMS short wrapper. Annex C (normative) specifies the gateway protocol. Annex D, Annex E and Annex F (informative) include encoding examples for APDUs. Annex G (normative) provides NSA Suite B elliptic curves and domain parameters. Annex H (informative) provides an example of an End entity signature certificate using P-256 signed with P-256. Annex I (normative) specifies the use of key agreement schemes in DLMS®/COSEM. Annex J (informative) provides examples of exchanging protected xDLMS APDUs between a third party and a server. Annex K (informative) lists the main technical changes in this edition of the standard.

This part of IEC 62056 specifies a model of a meter as it is seen through its communication interface(s). Generic building blocks are defined using object-oriented methods, in the form of interface classes to model meters from simple up to very complex functionality. Annexes A to F (informative) provide additional information related to some interface classes.

IEC 61158-3-2:2023 is one of a series produced to facilitate the interconnection of automation system components. It is related to other standards in the set as defined by the "three-layer" fieldbus reference model described in IEC 61158‑1.
Throughout the set of fieldbus standards, the term "service" refers to the abstract capability provided by one layer of the OSI Basic Reference Model to the layer immediately above. Thus, the data-link layer service defined in this document is a conceptual architectural service, independent of administrative and implementation divisions.

IEC 61158-1:2023 specifies the generic concept of fieldbuses. This document also presents an overview and guidance for the IEC 61158 eries by:
explaining the structure and content of the IEC 61158 series;
relating the structure of the IEC 61158 series to the ISO/IEC 7498-1 OSI Basic Reference Model;
showing the logical structure of the IEC 61784 series;
showing how to use parts of the IEC 61158 series in combination with the IEC 61784 series;
providing explanations of some aspects of the IEC 61158 series that are common to the type specific parts of the IEC 61158‑5 series including the application layer service description concepts and the generic fieldbus data types.

IEC 62351-9:2023 specifies cryptographic key management, primarily focused on the management of long-term keys, which are most often asymmetric key pairs, such as public-key certificates and corresponding private keys. As certificates build the base this document builds a foundation for many IEC 62351 services (see also Annex A). Symmetric key management is also considered but only with respect to session keys for group-based communication as applied in IEC 62351-6. The objective of this document is to define requirements and technologies to achieve interoperability of key management by specifying or limiting key management options to be used.
This document assumes that an organization (or group of organizations) has defined a security policy to select the type of keys and cryptographic algorithms that will be utilized, which may have to align with other standards or regulatory requirements. This document therefore specifies only the management techniques for these selected key and cryptography infrastructures. This document assumes that the reader has a basic understanding of cryptography and key management principles.
The requirements for the management of pairwise symmetric (session) keys in the context of communication protocols is specified in the parts of IEC 62351 utilizing or specifying pairwise communication such as:
• IEC 62351-3 for TLS by profiling the TLS options
• IEC 62351-4 for the application layer end-to-end security
• IEC TS 62351-5 for the application layer security mechanism for IEC 60870-5-101/104 and IEEE 1815 (DNP3)
The requirements for the management of symmetric group keys in the context of power system communication protocols is specified in IEC 62351-6 for utilizing group security to protect GOOSE and SV communication. IEC 62351-9 utilizes GDOI as already IETF specified group-based key management protocol to manage the group security parameter and enhances this protocol to carry the security parameter for GOOSE, SV, and PTP.
This document also defines security events for specific conditions which could identify issues which might require error handling. However, the actions of the organisation in response to these error conditions are beyond the scope of this document and are expected to be defined by the organizations security policy.
In the future, as public-key cryptography becomes endangered by the evolution of quantum computers, this document will also consider post-quantum cryptography to a certain extent. Note that at this time being no specific measures are provided.
This second edition cancels and replaces the first edition published in 2017. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) Certificate components and verification of the certificate components have been added;
b) GDOI has been updated to include findings from interop tests;
c) GDOI operation considerations have been added;
d) GDOI support for PTP (IEEE 1588) support has been added as specified by IEC/IEEE 61850-9-3 Power Profile;
e) Cyber security event logging has been added as well as the mapping to IEC 62351-14;
f) Annex B with background on utilized cryptographic algorithms and mechanisms has been added.