BS EN IEC 62541-4:2020

What is BS EN IEC 62541-4 about? 

BS EN IEC 62541-4 is part 4 of a multi-series standard with provides technical specifications for services relating to OPC unified architecture which ensures encryption and smooth flow of data. 

BS EN IEC 62541-4 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 occur via these Services. All interactions between OPC UA Clients and Servers occur via these Services. 

BS EN IEC 62541-4 gives detailed information about terms, definitions, abbreviated terms, conventions, service set model, request/response service procedures, service sets, service behavior as well as common parameter type definitions for OPC unified architecture. 

BS EN IEC 62541-4 gives services that are considered abstract because there is no particular RPC mechanism for their implementation. 

Note: IEC 62541-4 defined services are not compulsory for all OPC UA Servers. Other standards in normative references define the profiles that dictate which services need to be implemented in order to be compliant with a particular profile. 

Who is IEC 62541-4 for? 

IEC 62541-4 on OPC unified architecture is applicable to: 

• Companies shifting to service-oriented architecture 
• Consultants working with software architecture 
• Developers and designers of unified architecture 

Why should you use IEC 62541-4? 

OPC unified architecture is an interoperability standard for transferring data securely and reliably in the industrial automation and other industries. It is a platform- independent, service-oriented architecture that ensures a smooth flow of data across devices from various manufacturers. 

IEC 62541-4 provides you a comprehensive guide on service sets, security, common parameter type definitions, figures and tables which allow you to set up secure services, encrypt and audit them. 

IEC 62541-4 provides you with all the technical information about OPC unified architecture that combines all the performance services of the individual OPC specifications into one stretchable framework which is feasible to use. 

What’s changed since the last update? 

BS EN IEC 62541-4:2020 supersedes BS EN 62541-4:2015, which will be withdrawn on 17 August 2023. 

Changes in BS EN IEC 62541-4:2020 include – 

• Added ability to resend all data of monitored items in subscription using Resend Data method 
• Added Register2 and Find Servers On Network Services to support network-wide discovery using capability filters 
• Removed definition of software certificates. Will be defined in a future edition. 
• Added a section on how to use Authorization Services to request user access tokens, JSON Web Tokens (JWTs) as a new user token and a requirement to protect against user identity token attacks